
Class ZTX^"^! 

Book.._^LA4S"_ 
%ri^lrtN"J_a^Q_ 

COK^'HrCilT OEPOSfT 



FOOD INSPECTION'' 
and ANALYSIS 



FOR THE USE OF PUBLIC ANALYSTS, HEALTH OFFICERS, 
SANITARY CHEMISTS, AND FOOD ECONOMISTS 

BY 

ALBERT E. LEACH, S.B. 

Late Chief of the Denver Food and Drug Inspection Laboratory, Bureau of Chemistry, 

U. S. Department of Agriculture; Late Chief Analyst of the Massachusetts 

State Board of Health 

REVISED AND ENLARGED BY 

ANDREW L. WINTON, Ph.D., 

Formerly Chief of the Chicago Food and Drug Laboratory, Bureau of Chemistry, U. S. 

Department of Agriculture; Formerly in Charge of the^ A nalytical Laboratory, 

Connecticut Agricultural Experiment Station 



FOURTH EDITION 
TOTAL ISSUE, EIGHT THOUSAND 



NEW YORK 

JOHN WILEY & SONS, Inc. 

London: CHAPMAN & P a : T Limited 

1920 






Copyright, 1904, 1909. 

BY 

ALBERT E. LEACH. 



First Edition Entered at Stationers' HalL 



COYRIGHT, I913. 1920. 
BY 

Mrs. MARTHA T. LEACH. 



hvw -^ «^'^^ 



PRESS Ol' 

BRAUNWURTH ti CO. 

BOOKBINDERS AND PRINTERS 

BROOKLYN, N. Y. 



l\ 



(e)nLA5R54 48 



,-;ul 



^/ 



PREFACE TO FOURTH EDITION. 



The present revision has been carried out after a thorough search 
of the literature. A large amount of new material has been added or 
substituted for that in previous editions and the size of the book 
increased by 90 pages. While a somewhat different arrangement 
of the chapters may seem more logical, it was decided to retain the old 
order to which those who have hitherto used the book have become 
accustomed. The lists of references at the end of the chapters, which 
never aspired to be complete bibhographies, have been dropped and more 
attention has been given to footnote references. 

The reviser is indebted for criticisms and notes to many friends, 
especially the following: Prof. E. H. Farrington, Prof, E. S. Guthrie, 
and Dr. L. L. Van Slyke (dairy products). Prof. H. S. Grindley (meat), 
Mr. F. C. Atkinson, Mr. Carl S. Miner, and Prof. Harry Snyder (cereal 
products), Mr. M. C. Albrech, Mr. F. M. Boyles, and Mr. A. E. Paul 
(spices), Mr. H. S. Bailey, Prof. E. F. Ladd, and Dr. David Wesson 
(oils). Dr. C. S. Browne, Mr, A. Hugh Bryan, Dr. W. D. Home, and 
Mr. W. E. Rice (sugar), Mr. H. M. Loomis and Mr. W. E. Mathewson 
(colors), and Dr. A. R. Albright (flavoring extracts). 

A special feature is a final chapter by Prof. Gerald L. Wendt, on 
the determination of acidity by the hydrogen electrode, a method which 
seems destined to play an important part in food analysis. 

So far as possible original papers have been consulted, but whenever 
this was not possible owing to the war or other conditions the abstracts 
in the Experiment Station Record and Chemical Abstracts have proved 
invaluable. 

A. L. W. 

Wilton Conn., January, 1920. 

V 



PREFACE TO FIRST EDITION. 



In the preparation of the present work, the requirements of the public 
analyst are mainly kept in view, as well as of such officials as naturally 
cooperate with him in carrying out the provisions of the laws dealing 
with the suppression of food adulteration in states and municipalities. 
To this end special prominence is given to the nature and extent of adul- 
teration in the various foods, to methods of analysis for the detection of 
adulterants, and to some extent also to the machinery of inspection. 

While the analyst may not in all cases have directly to deal with the 
minuticB of food inspection, his work is so closely allied therewith that 
this branch of the subject is of vital interest and importance to him. 
Indeed, in many smaller cities one official often has charge of the entire 
work, combining the duties of both inspector and analyst. 

Endeavor has been made, furthermore, to deal with the general com- 
position of foods, and to give such analytical processes as are likely to 
be needed by the sanitary chemist, or by the student who wishes to 
determine the proximate components of food materials. 

It has been thought best to include brief synopses of processes of 
manufacture or preparation of certain foods and food materials, in cases 
where impurities might be suggested incidental to their preparation. 

In view of the fact that Massachusetts was the pioneer state to adopt, 
over twenty years ago, a practical system of food and drug inspection, 
and for many years was the only state to enjoy such a system, no apology 
is perhaps needed for more frequent mention of Massachusetts methods 
and customs than those of many other states, in which the food laws 
are now being enforced wiih equal zeal and efficiency. 

Considerable attention has been paid in the following pages to the 
use of the microscope in food analysis. Of the figures in the text illus- 

vii 



Viii PREFACE. 

trating the microscopical structure of powdered tea, coffee, cocoa, and 
the spices, fifteen have been reproduced from the admirable drawings 
of Dr. Josef Moeller, of the University of Graz, Austria. Acknowledg- 
ment is gratefully given Dr. Moeller for his kind consent to their use. 

The photomicrographs in half-tone, forming the set of plates at the 
end of the volume, were all made in the author's laboratory, and may 
be divided into three classes: ist, illustrations of powdered pure foods 
and food products, as well as of powdered adulterants; 2d, types of 
adulterated foods, chosen from samples collected from time to time in 
the routine course of inspection; and 3d, photographs of permanently 
mounted sections of foods and adulterants. 

While recent works covering the whole field of general food analysis 
are comparatively few, the number of treatises, monographs, government 
bulletins, and articles scattered through the journals, dealing with special 
subjects relative to food and its inspection, is surprisingly large, and from 
a painstaking review of these much information has been culled, for which 
it has been the author's intention at all times to give credit. 

Special mention should here be made of the valuable publications of 
the U. S. Department of Agriculture, both the bulletins issued from 
Washington, and those from the various experiment stations, an ever- 
increasing number of which are becoming engaged in human food 
work. The author has freely drawn from these sources, and especially 
from the data and material furnished by his coworkers in the recent 
and still pending labor of preparing food methods for the Association' of 
Official Agricultural Chemists, and he wishes to extend his thanks to 
all of them for their assistance. Appreciation is also expressed for the 
care and discrimination shown by Mr. L. L. Poates in the preparation of 
the cuts. Thanks are especially due to Mr. Hermann C. Lythgoe, 
Assistant Analyst of the Massachusetts State Board of Health, for his 
invaluable cooperation, and to Dr. Thomas M. Drown for helpful hints 
and suggestions. 

Boston, Mass., July i, 1904. 



TABLE OF CONTENTS. 



CHAPTER I. 



Food Analysis and Official Control i- 

Introductory, i. Food Analysis from the Dietetic Standpoint, 2. Commercial 
Food Analysis, 3. Systematic Food Inspection; Functions of the Official Analyst; 
Standards of Purity; Nature of Analytical Methods, 3-5. Adulteration of Food, 5. 
Misbranding, 6. A Typical System of Food Inspection, 6-9. Practical Enforcement 
of Food Laws; Publication; Notification; Prosecution, 10. 



CHAPTER II. 

The Laboratory and its Equipment 12-27 

Location, 12. Floor; Lighting; Ventilation; Benches, 13. Hoods, 14. Sinks 
and Drains, 15. Gas; Electricity; Steam, 17. Suction and Blast, 18. Apparatus, 
18-24. Reagents, 24. Equivalents of Standard Solutions, 25-26. Indicators, 27. 



CHAPTER III. 

Food, its Functions, Proximate Components, and Nutritive Value 28-40 

Nature and General Composition of Food; Fats, 28. Proteins; Classification 
of Nitrogenous Bodies, 29-34. Proteins, their Subdivisions, Occurrence, and 
Characteristic Tests, 29. Amino Acids, etc., 34- Bases; Alkaloids; Nitrates; 
Ammonia; Lecithin; Cyan Compounds, 35. Carbohydrates and their Classi- 
fication, 35-38. Organic Acids; Mineral or Inorganic Materials; Fuel Value of 
Food, 38. Calorimeters, 38-40. 



CHAPTER IV 

General Analytical Methods 41-67 

Proximate Analysis; Expression of Results, 41-42. Preparation of Sample, 43. 
, Specific Gravity; Methods and Apparatus, 43-48. Freezing Point; Moisture, 
49-50. Ash, 51. Extraction with Volatile Solvents, 52-56. Extraction with Immis- 
cible Solvents, 57. Nitrogen, 58-62. Protein and Amino Acid Nitrogen; Carbo- 
hydrates; Poisons, 63. Arsenic, 63-66. Colorimetric Analysis; Colorimeter, 66. 
Tintometer, 67. 

ix 



X TABLE OF CONTENTS. 

CHAPTER V 

PAGE 

The Microscope in Food Analysis 68-85 

Microscopical vs. Chemical Analysis; Technique of Food Microscopy, 68. 
Apparatus and Accessories, 69-71. Preparation of Vegetable Foods for Micro- 
scopical Examination, 72. Microscopical Diagnosis, 73. Vegetable Tissues and 
Cell Contents, under the Microscope, 74-77. Microscopical Reagents, 77-80. Pho- 
tomicrography; Appurtenances and Methods, 80-85. Microchemical Reactions, 
81. 

CHAPTER VI. 

The Refractometer 86-107 

Types, 86. Butyro-refractometer, 87. Refractometer Heater, 88. Manipula- 
tion, 88-90. Equivalents of Refractive Indices and Butyro-refractometer Read- 
ings, 91-92. Temperature Correction, 93. Abbe Refractometer, 94. Construc- 
tion; Manipulation, 95-97. Immersion Refractometer, 97-98. Manipulation, 
99-101. Equivalents of Refractive Indices and Immersion Refractometer Read- 
ings, 102-105. Strength of Solutions by Refractometer, 106. Temperature Cor- 
rections, 107. 

CHAPTER VII. 

Milk and Milk Products 108-204 

Milk; Composition; Characteristics; Acidity; Microscopy, 108. Color; Fat; 
Lactose, 109. Proteins and other Nitrogenous Bodies, 109-110. Citric Acid; 
Other Organic Constituents; Enzymes, no. Composition of Milk, 111-112. 
Composition of Ash, 112-113. Milk of Different Animals; Fore Milk and Strip- 
pings, 113. Colostrum, 114. Composition as related tv. Stage of Lactation, Age, 
Breed, Feed, etc., 114-116. Frozen Milk; Fermentations of Milk, 116. Analysis of 
Milk; Sampling, 117. Specific Gravity, 118-120. Total Solids, 119-121. Ash, 
121. Fat, by Extraction, by Centrifugal, and by Refractometric Methods, 121-131. 
Proteins; Casein, 132. Albumin; Other Nitrogenous Bodies, 133. Milk Sugar, 
by Optical Methods, 134-136, by Fehling's Solution, 136-138. Relation between 
the Various Milk Constituents; Calculation by Formulae, 138-141. Acidity, 140, 
Modified Milk and its Preparation, 142-144. 

Milk Adulteration and Inspection; Milk Standards, 144-146. Forms of Adul- 
teration, and Variation in Standard, 146-147. Rapid Approximate Methods of 
Examination, 148. Examination of Milk Serum; Constants, 149-154. Freezing 
Point, 153. Systematic Routine Examination, 154. Analytical Methods for 
Solids, Fat, and Ash, 155-158. Added Foreign Ingredients, 158. Coloring 
Matters and their Detection, 159-162. Preservatives, their Relative Efficiency 
and their Detection, 162-171. Added Cane Sugar, Starch, and Condensed 
Skimmed Milk, 171. Analysis of Sour Milk, 172. 

Homogenized Milk, 172. Analysis, 173. 

Pasteurized Milk; Enzyme Tests, 173-174. 

Fermented Milk; Kumiss, 174. Mazun; Analysis, 175. 

Condensed Milk; Composition, Standards, Adulteration, 175-178. Methods of 
Analysis, 178-183. Calculation of Fat in Original Milk, 183. 

Milk Powder, 184. Analysis, 185. 



TABLE OF CONTENTS. xi 

PAGE 

Cream; Composition, Standards, Adulterants, 186-187. Analytical Methods, 
187-190. 

Ice Cream; Standards, 191. Classification, Ingredients, 192. Methods of 
Analysis, 193-196. 

Cheese; Composition, Varieties, 196-197. Standards; Adulteration, 198. 
Analytical Methods, 199-203. 

Protein Preparations; Casein, 203. Lactalbumin, 204. 

CHAPTER VIII. 

Flesh Foods 205-266 

Meat; Structure and Components, 205-206. Proximate Composition of the 
Common Meats, 207-212. Meat Inspection, 207. Standards, 213. Preserva- 
tion; Storage, 214. Curing, 215. Antiseptics, 216. Drawn vs. Undrawn Poultry; 
Spoilage, 217. Effect of Cooking, 217-218. Canned Meats, 218-219. Sausages 
220-222. Analytical Methods; Water, 223. Fats, 224. Nitrogenous Bodies, 
225-230. Ash; Acidity, 230. Starch, 231. Horseflesh, 232. Glycogen, 233-236. 
Biological Tests for Horseflesh, 236. Sugars, 237. Preservatives, 238-240. CoLi- 
ing Matter, 240-241. Frozen Meat, 241. 

Meat Extracts; Manufacture, 242. Constituents, 243. Meat Juices, 244. 
Peptones and Seasonings, 245. Composition of Extracts, etc., 246-249. Bouillon 
Cubes, 250-251. Yeast Extracts, 252. Standards for Extracts, etc., 252-253. 
Analytical Methods, 253. Water; Ash; Fat; Nitrogen, 253. Nitrogenous Bodies, 
253~257. Acidity, 257. Sugars; Glycerol; Preservatives, 258. 

Gelatin, 258. 

Fish; Structure; Composition, 259-261. Crustaceans and Mollusks, 262. 
Canned, Salted and Smoked Fish, 263. Floating of Shellfish, 264. Preservatives 
in Fish and Oysters; Colors, 265. 

Concentrated Foods for Armies and Campers, 265-266. 

CHAPTER IX 

Eggs 267-279 

Nature; Weight, 267. Composition, 268. Shell; Membrane; Egg White, 269. 
Constituents, 270. Egg Yolk, 270. Constituents, 271-272. Grades of Eggs; 
Preservation, 272. Cold Storage, 273. Spoilage, 274. Frozen Eggs, 275. Desic- 
cated Eggs, 276. Analytical Methods, 276-278. Lecithin; Preservatives, 278. Egg 
Substitutes, 278-279. Custard Powders, 279. 

CHAPTER X. 

Cereals and their Products, Legumes, Vegetables, and Fruits 280-377 

Composition of Cereals, Vegetables, Fruits, and Nuts, 280-284. Methods 
of Proximate Analysis, 285-288. Carbohydrates of Cereals, 288. Starch: Detec- 
tion, Varieties, Classification, Microscopical Examination, 288-292. Starch 
Determination, 292-293. Sugars, 293. Cellulose, 294. Pentosans, 294-304. 
Carbohydrates of Cereals, 304-305. Proteins of Cereals and Vegetables, 305-309. 
Proteins of Wheat, 307-309. Proteins of Other Cereals and Vegetables, 309. 
Ash, 310. Scheme for Ash Analysis, 311-313. Sulphur, 313. Chlorine, 314. 
Microscopy of Cereal Products, 314-320. 



xii TABLE OF CONTENTS. 

PAGE 

Flour; Milling; Composition, 320-321. Graham Flour, 322. Flour of Other 
Cereals, 323. Damaged Flour; Ergot, 323. Adulteration, 324-327. Alum; 
Bleaching, 325. Inspection and Analysis; Fineness; Color, 326-327. Absorp- 
tion, and Dough Tests, 327. Expansion of Dough; Baking Tests, 328-330. 
Ash, 330. Gluten; Gliadin, 331. Glutenin, etc., 332. Acidity; Improvers, 333. 
Bleaching; Nitrites, 334-335. Chlorine, 335. Bamihl Test, 336. 

Corn Meal; Manufacture, 337. Composition; Spoilage; Acidity, 338. 

Bread; Composition; Varieties, 338-340. Water; Acidity, 340. Fat; Yeast 
Foods, 341. Alum; Wrapping; Cake, 342. Analytical Methods, 343. Compo- 
sition of Cake, 343. 

Leavening Materials; Yeast, 343. Compressed Yeast; Dry Yeast, 344. Com- 
position, 345. Starch in Compressed Yeast; Microscopy, 346. Carbon Dioxide, 

347- 

Chemical Leavening Materials, 348. Baking Powders; Classification, 349. 
Composition, 350-351. Adulteration, 351. Cathartics in Residue; Alum Salts; 
Analytical Methods; Sodium Bicarbonate, 352. Cream of Tartar, 353. Carbon 
Dioxide, 353-356. Tartaric Acid, 356-359. Starch, 360. Alumina; Lime; 
Potash; Soda, 361. Phosphoric Acid; Sulphuric Acid; Ammonia; Arsenic; Lead, 
362. 

Semolina and Edible Pastes, 363. Macaroni, etc.; Noodles, 364. Adulteration, 
365. Analytical Methods; Lecithin-Phosphoric Acid, 366. Colors, 366-369. 

Cereal Breakfast Foods; Nature and Composition, 369-371. 

Infants' and Invalids' Foods, 371. Preparation, 372. Composition, 373. Dia- 
betic Foods, 373-375- Analytical Methods, 375-377. 



CHAPTER XI. 

Tea, Coffee, and Cocoa 378-421 

Tea; Varieties; Method of Manufacture, 378. Compositions, 379-381. Analyt- 
ical Methods, 381. Protein; Ash; Essential Oil; Insoluble Leaf, 382. Extract, 
383. Tannin, 383-385. Theine, or Caffeine, 385-387. Facing, 387. Spent 
Leaves; Foreign Leaves, 388. Stems and Fragments, 389. Astringents; Tea 
Tablets, 390. Microscopy, 391. 

Coffee; Nature; Constituents, 392. Composition, 393-395. Substitutes and 
Adulterants, 395. Analytical Methods, 395. Caffetanic Acid, 395-396. Caffeine; 
Adulteration, 397. Imitation Coffee; Coloring; Glazing; Methods, 398. Micros- 
copy, 399. Chicory; its Microscopical Structure, 400-402. Composition of 
Chicory, and its Detection in Coffee, 402-403. Date Stones, 403. Hygienic 
Coffee, 404-405. Substitutes, 406. 

Cocoa and Cocoa Products, 406. Manufacture, 407. Composition, 407-409. 
Theobromine and Nitrogenous Substances; Pentosans, 410. Milk Chocolate; 
Compounds, 410. Analytical Methods; Moisture; Ash, 411. Protein; Casein, 
412. Theobromine and Caffeine, 413. Crude Fiber; Reducing Matters, 414. 
Starch; Pentosans; Sucrose; Lactose, 415. Cocoa Red, 416. Adulteration, and 
Standards, 417. Addition of Alkali; Microscopy, 418-419. Cocoa Shells; Added 
Starch, Sugar, Fat and Colors, 420-421. 



♦ TABLE OF CONTENTS. xiii 

CHAPTER XII. 

PAGE 

Spices 422-485 

Nature; Adulteration; General Methods of Proximate Analysis, 422. Moisture; 
Ash, 423. Ether, and Alcohol Extract; Nitrogen, 424. Starch; Crude Fiber; 
Volatile Oils, 425. Microscopy, 426. Spice Adulterants, 426-427. 

Cloves; Composition, 426-429. Tannin, 429. Microscopy, 430-431. Stand- 
ards; Adulterants; Clove Stems; Exhausted Cloves, 432. Cocoanut Shells, 433. 

Allspice; Nature, 434. Composition; Tannin, 435. Microscopy, 436-437. 
Standards; Adulteration, 438. 

Cassia and Cinnamon; Nature, 438-439. Composition, 439-440. Microscopy, 
440-442. Standard; Adulterants; Foreign Bark, 442. 

Pepper; Nature, 442. Composition, 443-446. Nitrogen Determination, 446. 
Piperin, 447. Microscopy, 447-449. Standards; Adulteration, 449. Pepper 
Shells and Dust, 449. Olive Stones, 450. Buckwheat, 451. Long Pepper, 452. 

Red Pepper (Cayenne, Paprika, etc.); Nature, 452-453. Constituents, 454. 
Composition, 455-458. Microscopy, 458-460. Adulteration, 460-462. Added 
Oil in Paprika, 461. 

Ginger; Nature, 462. Composition, 463-464. Exhausted Ginger, and its 
Detection, 464-465. Microscopy, 465. Standards; Adulteration, 466. 

Turmeric; Nature; Composition, 467. Microscopy, 468. 

Mustard; Nature, 469-470. Composition, 471-473. Analytical Methods; 
Potassium Myronate; Sinapin Thiocyanate; Myrosin; Volatile Oil, 473-474. 
Microscopy, 475. Standards; Adulteration, 476. Wild Mustard, 476-477. 
Coloring Matter, 478. Prepared Mustard; Composition, Adulteration, 478-479. 
Analytical Methods, 479. 

Nutmeg and Mace; Nature, 480. Composition of Nutmeg, 480-481. Micros- 
copy, 481. Standards; Adulteration, 482. Composition of Mace, 482-483. 
Microscopy; Standards; Adulteration, 484. Bombay or Wild Mace and its 
Detection; Macassar Mace, 484-485. 

CHAPTER XIII. 

Edible Oils and Fats 486-585 

Constituents; Solubihties, 486. Fatty Acids, 486-487. Saponification, 487. 
Hydrogenation; Analytical Methods; Judgment of Purity, 488. Rancidity; Filter- 
ing; Weighing; Measuring, 489. Specific Gravity, 490-492. Viscosity, 492. 
Refraction, 493-495. Melting Point, 496-497. Reichert-Meissl Process for 
Volatile Fatty Acids, 497-499. Polenske Number, 499-500. Soluble and Insol- 
uble Fatty Acids, 501-503. Saponification Number, 503-504. Iodine Absorption 
Number; Hiibl Method, 504-507. Hanus Method, 50S. Wijs Method, 509. 
Bromine Absorption Number, 509-510. Thermal Tests, 510. Maumene Test, 511. 
Bromination Test, 511-514. Acetyl Value, 514-516. Valenta Test, 516. Elaidin 
Test, 517. Free Fatty Acids, 518. Titer Test, 518-520. Unsaponifiable Matter, 
520. Cholesterol and Phytosterol, 520-521. Separation and Crystallization, 
522-525. Bomer Phytosterol Acetate Test, 525-526. Paraffin; Microscopy, 527. 
Constants of Edible Oils and Fats, 527-529. Olive Oil; Source, 530. Nature; 
Composition; Substitutes, 531. Standards, 531-532. Tests for Adulteration, 
532-535. Cottonseed Oil; Source; Nature; Composition, 535. Standards; 
Bechi Test, 536. Halphen Test, 537, Sesame Oil, 537. Adulterants; Tocher 



xiv TABLE OF CONTENTS. 



Test; Baudonin Test; Vlllavechia and Fabric Test, 538. Rape Oil, 539. Mustard 
Oil; Charlock Oil, 540. Corn Oil, 541. Sitosterol, 542. Peanut Oil; Composi- 
tion; Standards; Adulterants, 542. Renard Test, 543-544. Bellier Test, 544- 
545. Soy Oil, 545. Composition; Tests, 546. Linseed Oil, 547. Poppyseed Oil, 
547. Sunflower Oil, 547-548. Rosin Oil, 548-549. Cocoanut Oil, 549. Palm 
Kernel Oil; Cocoa Butter; Tallow, 550. 

Butter, 551. Composition, 551-552. Effects of Feeding; Analytical Methods, 
552. Water, 553-555. Fat; Casein, 555. Ash; Lactose; Salt; Standards, 556. 
Colors, 557-559. Preservatives, 560-562. Reno\ated or Process Butter, 563. 
Oleomargarine, 563. Oleo Oil, 564. Coloring; Detection of Palm Oil, 565. 
Adulterants, 566. Healthfulness; Distinction from Butter, 567-571. Distinguish- 
ing Tests for Butter, Process Butter, and Oleomargarine, 571. Foam Test, 572, 
Milk Test, 573. Curd Tests, 574. Microscopical Examination, 574-576. Nut 
Butter, 576. 

Lard; Nature, 577. Constants, 578. Effects of Feeding; Oily Hogs; Standards; 
Lard Oil, 579. Compounds; Substitutes; Adulterants, 580-582. Analytical 
Methods, 582. Beef Fat, 582-583. Various Oils-,. Nickel in Hydrogenated Sub- 
stitutes, 584. Paraffin, 585. 

CHAPTER XIV. 

Sugar and Saccharine Products 586-681 

Nature; Classification, 586. Cane Sugar; Standard, 587. Sugar Cane; Manu- 
facture of Cane Sugar, 588. Composition of Cane Sugar Products, 589. Sugar Beet; 
Manufacture of Beet Sugar, 590. Refining Sugar; Maple Products, 591. Com- 
position, Standards, and Adulteration of Maple Products, 592-594. Sorghum, 595. 
Grape Sugar; Levulose, 596. Malt Sugar; Dextrin; Commercial Glucose, 597- 
598. Standards and Healthfulness of Glucose; Milk Sugar, 599. Raffinose, 600. 

Polariscope, 600. Saccharimeter, 600-606. Comparison of Scales and Normal 
Weights, 606. Specific Rotary Powers, 607. Birotation, 608. ! 

Analysis of Cane Sugar and its Products; Tests for Sucrose, 608. Moisture; 
Ash; Non-sugars, 609. SucroseDeterminationby Polariscope, 610-613. Inversion; 
Clerget's Formula, 611. Detection and Determination of Invert Sugar; Ultra- 
marine in Sugar, 613. Copper Reduction, 614. Volumetric Feliling Process, 
615-617. Gravimetric Fehling Methods, 617. Defren-O'Sullivan Method, 618- 
621. Munson and Walker Method, 622-631. Allihn Method, 632-634. Elec- 
trolytic Apparatus, 634-637. Meissl and Hiller Invert Sugar Method, 637-641. 
Sucrose Determination by Fehling Solution, 642. 

Analysis of Molasses and Syrups, 642. Solids; Ash; Polarization, 643-650. 
Double Dilution Method of Polarizing; Raffinose Determination, 650. Adultera- 
tion of Molasses and Standards, 651. Glucose Determination, 651-654. Ashing 
Saccharine Products, 654. Tin Determination, 655. 

Separation and Determination of Various Sugars, 655, 656. 

Analysis of Maple Products; Moisture, 656. Ash; Malic Acid Value, 657. 
Lead Number, 658. Hortvet Number, 659-660. Sy's Method, 660. Snell Elec- 
trical Conductivity Method, 661. 

Analysis of Glucose; Polarization Formulae, 661-662. Dextrin; Ash; Sulphurous 
Acid; Arsenic, 663. 

Honey; European; Canadian, 664. American; Hawaiian, 665-666. Cuban; 
Mexican; Haitian, 667. Adulteration, 668-669. 



TABLE OF CONTENTS. 



XV 

PAGE 



Analysis of Honey; Moisture, 670. Ash; Polarization; Reducing Sugar; 
Levulose, 671. Dextrose; Sucrose; Dextrin, 672. Acids; Glucose, 673. Invert 
Sugar; Distinction of Honeydew from Glucose, 674. Beeswax, 675-676. 

Confectionery; Standard; Adulteration; Colors, 677. Analytical Methods; 
Mineral Matter; Lead Chromate, 678. Ether Extract; Paraffine, 679. Starch- 
Polarization, 680 Alcohol; Colors; Arsenic, 681. 



CHAPTER XV. 

Alcoholic Beverages 682-787 

Alcoholic Fermentation, 682. Alcoholic Liquors and State Control, 683. Liquor 
Inspection, 684-686. Analytical Methods Common to all Liquors; Specific Gravity, 
686. Detection and Determination of Alcohol, 686-689. Alcohol Tables, 690-703! 
The Ebullioscope, 704-705. Extract; Ash; Artificial Sweeteners, 706. 

Fermented Liquors; Cider, 707. Manufacture, 707-708. Composition, 708-711. 
Adulteration, 711. Perry, 712. Wine; Manufacture, 713. Classification; 
Varieties, 714-715- Constituents, 715-716. Composition, 716-718. Standards, 
716-720. Adulteration, 720. Plastering; Cane Sugar, 721. Watering, 722-723. 
Fortification, 723-724. Pomace Wine; Piquette, 724. Various Adulterants; Fruit 
Wines, 725. Analytical Methods; Extract; Acidity, 726. Volatile Acidity, 726, 
731- Extract Table, 727-729- Tartaric Acid, 731-732. Lactic Acid, 732-733! 
Sugars; Glycerol, 734. Sulphates; Chlorides; Nitrates; Tannin, 735. Foreign 
Colors, 736-737- 

Malt Liquors; Beer; Malting, 738. Brewing; Varieties of Beer and Ale, 739. 
Composition, 740-741- Malt and Hop Substitutes, 741. Adulteration and 
Standards, 742-743- Malted vs. Non-malted Liquors, 743-744. Malt vs. Substi- 
tutes, 744-745- Preservatives; Arsenic; Temperance Beers, 746. Analytical 
Methods; Alcohol, 747. Extract, 747-755- Original Gravity, 754-756. Sugars; 
Dextrin; Glycerol, 756. Acids; Proteins; Phosphoric Acid, 757. Carbon 
Dio.xide, 758. Bitter Prmciples, 759-760. Arsenic, 760; Malt Extract, 761-762. 

Distilled Liquors, 762. Standards for Spirits, 763. Fusel Oil, 763-764. Whiskey, 
764. Manufacture, 764-765- Standards, 765-767. Composition, 767-770! 
Adulteration, 770-771- Brandy, 771. Manufacture, 771. Composition; Stand- 
ards, 772. Adulteration, 773. Rum; Composition; Standards, 774-775. Gin; 
Composition, 776. Analytical Methods; Extract; Acids; Esters; Aldehydes! 
777- Furfural, 778. Fusel Oil, 778-781. Methyl Alcohol, 781-784. Caramel! 
784-785. Opalescence Test, 785. 
Liqueurs and Cordials, 786. Composition; Analytical Methods, 787. 

CHAPTER XVI. 

V^^^^^^ 788-811 

Acetic Fermentation; Varieties of Vinegar, 788. Manufacture, 789. Compo- 
sition, 790. Cider Vinegar, 790-791- Wine Vinegar, 792. Malt Vinegar, 792- 
793- Spirit, Glucose, and Molasses Vinegars, 794. Wood Vinegar; Analytical 
Methods; Density; Extract; Ash; Phosphoric Acid, 795. Nitrogen; Acidity, 
796. Alcohol; Mineral Acids, 797-798. Malic Acid, 798. Lead Precipitate, 799! 
Acid Potassium Tartrate; Sugars, 800-801. Pentosans, 801. Glycerol, 801-803. 
Adulteration of Vinegar; Standards, 803-804. Artificial Cider Vinegar, 805. 



xvi TABLE OF CONTENTS. 

PAGE 

Character of Residue and Ash, 805-806. Character of Sugars, 807. Glycerol, 808. 
Direct Tests, 808-809. Composition of Artiucial Cider Vinegars, 809. Detection 
of Adulterants, and Metallic Impurities, 810-81 1. 



CHAPTER XVII. 

Artificial Food Colors 812-875 

Extent of Use; Objectionable Features, 812. Toxic Effects, 813-814. Harm- 
ful and Harmless Colors, 815. 

Mineral Colors; Detection, 816. 

Lakes; Detection, 817. 

Vegetable and Animal Colors, 817. Dyeing Tests; Reactions on Fiber, 818-819. 
Extraction with Immiscible Solvents, 818-820. Reactions in Aqueous Solution 
and with Sulphuric Acid, 820-823. Special Tests; Orchil; Logwood; Turmeric; 
Caramel, 821. Indigo; Cochineal, 824. 

Coal-tar Colors, 824. Allowed Colors, 825-826. Examination of Coal-tar 
Food Colors, 826. Analytical Schemes, 827. Rota Scheme, 827-832. Separa- 
tion and Identification of Allowed Colors, 833-836. Quantitative Separation of 
Acid Colors, 836-839. Analysis of Colors, 839. Spectroscopic Examination, 840. 
Detection of Coal Tar Colors in Foods, 840. Basic and Acid Dyes; Wool Dyeing 
Methods, 841-842. Extraction with Amyl Alcohol, 843. Extraction with Acetic 
Ether; Separation with Ether; Extraction of Dried Residues, 844. Special Tests, 
844-845. Loomis Scheme, 845-852. Reactions of Dry Colors or Dyed Fibers, 
853. Mathewson's Tables, 854-858. Mathewson Method for Separation by 
Immiscible Solvents and Identification, 859-867. Mathewson's Tables, 868-875. 



CHAPTER XVIII. 

Food Preservatives 876-904 

Preservation of Food, 876. Regulation of Antiseptics, 877. Commercial Food 
Preservatives, 878-879. Formaldehyde, 879. Determination in Preservatives, 
880. Detection in Food, 881-882. Determination, 883. Boric Acid, 883. Deter- 
mination in Preservatives, 884-885. Detection in Foods, ^885-886. Determina- 
tion, 886-887. Salicylic acid, 887. Detection, 8S8-889. Determination, 890. 
Benzoic Acid; Sodium Benzoate, 890. Detection, 891-893. Determination, 893- 
896. Sulphurous Acid, 896. Detection; Determination, 897-898. Formic Acid, 
898. Detection, 899. Determination, 900-901. Fluorides, Fluosilicates, Fluo- 
borates, 901. Detection, 902. Beta-Naphthol; Detection, 903. Asaprol or 
Abrastol, 903. Detection, 904, 



CHAPTER XrX. 

Artificial Sweeteners 905-910 

Extent of Use; Saccharin, 905. Detection of Saccharin, 906-907. Deter- 
mination, 907-908. 

Dulcin; Detection, 90S 909. Determination of Dulcin, 909-910. Glucin, 910. 



TABLE OF CONTENTS. xvii 

CHAPTER XX. 

PAGE 

Flavoring Extracts and their Substitutes 911-956 

Vanilla Extract, 911. Vanilla Bean, 911-912. Composition, 912. Vanillin; 
Exhausted Vanilla Beans; Preparation of Vanilla Extract, 913. Composition of 
Vanilla Extract, 914-916. Tonka Bean; Coumarin; Standards; Adulteration of 
Vanilla Extract, 917. Artificial Extracts, 918. Analytical Methods; Detection 
of Artificial Extracts, 919. Determination of Vanillin and Coumarin, 920-923. 
Tests for Coumarin, 923-924. Vanillin and Coumarin under the Microscope, 924. 
Normal Lead Number, 925. /Vcetanilide, 925-926. Glycerol; Alcohol; Caramel, 
926. Acidity; Colors, 927. 

Lemon Extract, 927. Standards, 927-928. Adulteration, 928-929. Analytical 
Methods, 929. Determination of Lemon Oil, 929-932. Alcohol, 932. Total 
Aldehydes, 933-934. Citral, 934-935. Methyl Alcohol, 935. Colors; Solids; 
Ash, 936. Glycerol; Examination of Lemon Oil, 937. Constants of Lemon and 
other Oils, 938. Citral, Citronellal, and other Adulterants, 938-939. Lemon Oil; 
Analytical Methods: Density; Refraction; Rotation, 939. Citral; Aldehydes; 
Physical Constants, 940. Pinene; Alcohol, 941. 

Orange Extract; Standards, 941-942. Analytical Methods, 942. Almond 
Extract; Oil of Bitter Almonds, 942. Benzaldehyde; Standards; Adulteration, 
943. Analytical Methods; Determination of Benzaldehyde, 944-945. Nitro- 
benzol; Distinction and Separation from Benzaldehyde, 945-946. Artificial Benzal- 
dehyde; Alcohol; Hydrocyanic Acid, 946. Wintergreen Extract; Standards; 
Adulteration, 947. Determination of Wintergreen Oil; Peppermint Extract; 
Peppermint Oil, 948. Standards; Analytical Methods, 949. Spearmint Extract, 
949. Spice Extracts; Standards, 949-951. Analytical Methods, 951-953. Rose 
Extract; Standards; Determination of Rose Oil, 953. Imitation Fruit Flavors, 
954-956. Determination of Esters, 956, 



CHAPTER XXI. 

Vegetable and Fruit Products 957-1020 

Canned Vegetables and Fruits; Method of Canning, 957-958. Composition, 
959. Decomposition; Swells; Springers, 960. Metallic Impurities, 961. Action 
of Fruit Acids on Tin Plate, 961-964. Action of Fruits and Vegetables on Differ- 
ent Weights of Tin Coating, 964-965. Salts of Lead, 965. Salts of Zinc, 966. 
Salts of Copper, 967-968. Salts of Nickel, 968. Toxic Effects of Metallic Salts; 
Preservatives, 969. Soaked Goods; Analytical Methods; Gases from Spoiled 
Cans, 970. Drained Solids, 971. Tin and Lead in Tin Plate and Alloy, 972. Tin, 
Copper, Lead, Zinc, and Nickel, 973-977. 

Ketchup; Standards, 977. Process of Manufacture; Composition, 978. Decayed 
Material; Refuse, 978-980. Foreign Pulp; Preservatives; Colors, 980. Analytical 
Methods; Solids; Sand, 981. Sugars; Citric Acid, 982. Lactic Acid, 983. Micro- 
scropy, 984. 

Pickles, 984. Composition, 985. Adulteration; Horseradish, 986. 

Preserves; Fruit Butter, 986. Mince Meat; Pie Filling, 987. Maraschino Cher- 
ries, 988-989. 

Jams and Jellies, 989. Composition; Adulteration, 990-993. Compounds; 
Imitations, 994-995. .'Vnalytical Methods, 995. Solids; Ash; Acidity, 996. 



XVlll TABLE OF CONTENTS. 



Protein, 997. Sugars, 997-999. Glucose; Dextrin, 999. Alcohol Precipitate; 
Colors, 1000. Preservatives; Sweeteners; Starch; Gelatin, looi. Agar-agar; 
Apple Pulp; Fruit Tissues, 1002. 

Dried Fruits, 1002. Lye Treatment; Sulphuring, 1003. Moisture; Spoilage; 
Zinc, 1004. 

Fruit Juices; Composition, 1004. Grape Juice, 1005. Sweet Cider, 1006. Lime 
Juice, 1006-1007. Analytical Methods; Acidity, 1007. Tartaric and Malic Acids, 
1008-1009. Citric Acid, 1009-1010. 

Fruit Syrups, loio-ioii. 

Non-Alcoholic Carbonated Beverages; Soda Water, loii. Syrups, 1012. 
Bottled Beverages, 1012-1013. Sweeteners; Acids; Preservatives, 1013. Colors, 
Foam Producers; Habit-forming Drugs, 1014. Analytical Methods, 1014. Solids; 
Ash; Acids; Sugars; Flavors; Colors; Preservatives; Sweeteners; Alcohol, 1015. 
Saponin, 1015-1017. Caffein; Cocaine, loi 7-1020. 



CHAPTER XXn. 

Determination of Acidity by Means of the Hydrogen Electrode 1021-1039 

Practical Value, 1021. Principle of Method, 1022-1023. Theory of Method, 
1024. Apparatus, 1025-1026. Hydrogen Electrode, 1027. Calomel Electrode, 
1028. Electrical Instruments, 1029. Titration, 1030. Typical Curves, 1030-1033. 
Titration of Milk, 1033-1034. Tea and Coffee, 1035. Acidity of Fruit Juices, 
1035-1038. Effects of Ripening, 1038-1039, 



APPENDIX. 

The Food and Drugs Act, 1041. The Meat Inspection Law, 1045. 



TABLE OF CONTENTS xix 

PLATES I-XL. 
Photomicrographs of Pure and Adulterated Foods and of Adulterants. 

Cereals: Barley, I. Buckwheat, II, III. Corn, III, IV. Oat, IV, V. Rice, V, 
VI. Rye, VI, Vn. Wheat, VIII. 

Legtimes: Bean, IX. Lentil, IX, X. Pea, X, XL 

Miscellaneous Starches: Potato; Arrowroot; Tapioca, XII. Turmeric; Sago, XIII. 
Coffee, XIV, XV. Chicory, XV, XVI. Cocoa, XVI, XVII. Tea, XVIII. 

Spices: Allspice, XVIII, XIX. Cassia, Cinnamon, XX-XXII. Cayenne, XXII- 
XXIV. Cloves; Clove Stems, XXIV-XXVII. Ginger, XXVII-XXIX. Mace, XXIX. 
Nutmeg, XXX. Mustard, XXXI-XXXIII. Pepper, XXXIII-XXXVI. 

Spice Adulterants: Olive Stones; Cocoanut Shells, XXXVL Elm Bark; Sawdust; 
Pine Wood, XXXVII. 

Edible Fats: Pure Butter; Renovated Butter; Oleomargarine, XXXVIII. Lard 
Stearin, XXXIX. Beef Stearin, XL. 

PLATE XLI. 

Minimum Percentages of Alcohol in Wines Corresponding to Halphen Ratios. 



FOOD INSPECTION AND ANALYSIS. 



CHAPTER I. 
FOOD ANALYSIS AND OFFICIAL CONTROL, 

INTRODUCTORY. 

The general subject of food analysis, in so far as the public health is 
concerned, is to be considered from two somewhat different standpoints: 
first, from the outlook of the government, state, or municipal analyst, whose 
mission it is to ascertain whether or not the food may properly be con- 
sidered pure or free from aduUeration; and second, from the point of view 
of the food economist, whose aim is to determine its actual composition 
and nutritive value. The one protects against fraud and injury, the 
other furnishes data for the arrangement of dietaries and for an intelUgent 
conception of the role which the various nutrients play in the metaboHsm 
of matter and energy in the body. The two fields are as a rule distinct each 
from the other, often • involving, in the examination of the food, different 
methods of procedure. 

Official Control of Food.— In view of the importance of the consideration 
of food with reference to its purity, an ever-increasing number of states 
have realized the necessity of protecting their citizens from the unscrupu- 
lous manufacturers who in various lines are seeking to produce cheaper 
or inferior articles of food in close imitation of pure goods. Many of 
the states have laws in accordance with which the sale of such impure 
or aduherated foods is made a criminal offense, and some, but not all 
of these, are provided with public analysts and other officers to enforce 
these laws and punish the offenders. Numerous communities are awake 
to the importance of municipal control of such commonly used articles 
of food as milk, butter, and vinegar, and in many cases have machinery 
of their own for regulating the sale of these foods. 



2 FOOD INSPECTION AND ANALYSIS. 

Since January i, 1907, the federal government has been actively en- 
gaged in the enforcement of the national food law of June 30, igo6, through 
the Bureau of Chemistry of the U. S. Department of Agriculture. In 
addition to the central laboratories of this Bureau at Washington, a num- 
ber of branch laboratories have baen established in the principal cities of 
the United States to enforce the provisions of the national law which regu- 
lates interstate commerce in foods, as well as their manufacture and sale 
in the territories and the District of Columbia, and their importation from 
foreign countries. 

Food Analysis from the Dietetic Standpoint. — The study of the prin- 
ciples of dietetics has been given increased attention during the last decade 
in the curricula of many of the technical schools and colleges. Much 
has been accomplished by certain of the state experiment stations working 
as a rule in connection with the United States Department of Agriculture 
along this line. Investigations of this character are especially valuable, 
and are indeed rendered necessary by the general tendency of the modern 
physician to regard the hygienic treatment of disease, especially with 
reference to the matter of diet, as often of far greater importance than 
the mere administering of drugs. 

The food economist studies the varying conditions of age, sex, occupa- 
tion, environment, and health among his fellow men, with a view to show- 
ing what foods are best adapted to supply the special requirements of 
various classes. The quantity and proportion of protein, fat and carbo- 
hydrates, or of fuel value best suited for the daily consumption of a given 
class or individual having been determined, dietaries are made up from 
various food materials to supply the need with reference as far as possible 
to the taste and means of the consumer. 

Experiments are made on famihes, clubs, or individuals, representing 
various typical conditions of life, and extending over a given period, dur- 
ing which records are kept of the available food materials on hand and 
received during the term of the experiment, as well as of those remaining 
at the end. In the case of individuals, additional records may be kept 
of the amount and composition of the urine and feces. From such data 
the physiological chemist calculates the amount of nutrients utilized, 
and studies the metabolism of material in the human body. 

Up to this point no very extensive apparatus is required, but if in 
addition the incone and outgo of heat and energy are to be studied, which 
are important to a complete investigation of the economy of food in the 
body, the student will require a respiration calorimeter and its appurtc- 



FOOD ANALYSIS AND OFFICIAL CONTROL. 3 

nances. The calorimeter is so constructed that an individual may be 
confined therein for a term of days under close observation and with 
carefully regulated conditions. Such an equipment involves a large 
expenditure and is to be found in but few laboratories. 

It is not the purpose of the present work to go beyond the strictly 
chemical or physical processes involved in making the analyses by which 
the proximate components of the foods are determined. For more com- 
plete information in the field of dietary studies and the metabolism of 
matter and energy in the body, the student is referred especially to the 
investigations of Atwater and his co-workers, as published in the annual 
reports of the Storrs Experiment Station at Middletown and in the bulle- 
tins of the U. S. Department of Agriculture, Office of Experiment Stations, 
also to studies conducted by Benedict of the Carnegie Institution. 

Commercial Food Analysis. — The proper preparation of food products 
has long ceased to be carried on by the hap-hazard rule-of-thumb methods 
that formerly prevailed. Now in the manufacture of many prepared foods 
and condiments, especially on a large scale, it has become a necessity to 
use scientific processes, rendered possible only by the employment of 
skilled chemists. In fact it is coming to be more and more common for 
food manufacturers to establish chemical laboratories in connection with 
their works, in the interests both of economy and of improved production. 

Frequently disputed points arise in the enforcement of the food laws 
that render the services of the private food analyst of great importance 
both to manufacturer and dealer. Thus a wide field is open to the analyst 
of foods outside the domain of the government or state laboratory, either 
in connection with the large food manufacturing plants directly, or m 
private laboratories for experimental research, or for analytical control 
work. 

SYSTEMATIC FOOD INSPECTION. 

Functions of the Official Analyst. — The public analyst is employed by 
city, state, or government to pass judgment on various articles of food 
taken from the open market by purchase or seizure, either by himself or 
by duly authorized collectors employed for the purpose. The sole object 
of his examination is to ascertain whether or not such articles of food con- 
form to certain standards of purity fixed in some cases by special law, and 
in others by common usage or acceptance. Such a public analyst need not 
concern himself with the dietetic value of the food or whether it is of high 
or low grade. It is for him to determine simply whether it is genuine or 



4 FOOD INSPECTION AND ANALYSIS. 

adulterated within the meaning of the law, and, if adulterated, how and 
to what extent. Aside from his skill as a chemist, it is often necessary for 
him to possess other no less important qualifications, chief among which 
are his ability to testify clearly and concisely in the courts, and to meet at 
any time the most rigid kind of cross-examination, it being of the utmost 
importance that he understand thoroughly the nature of evidence. 

Standards of Purity for Food Products.* — Under an act of Congress 
approved March 3, 1903, standards of purity for certain articles of food 
have been established as official standards for the United States by the 
Secretary of Agriculture. The earlier of these standards were formulated 
under the Secretary's direction by a committee of the Association of Official 
Agricultural Chemists. Later, however, a joint committee of that asso- 
ciation and of the association composed of state and national food officials 
has had charge of this work and still later a joint committee of these organ- 
izations and the Bureau of Chemistry. Standards have been adopted, 
covering the entire range of food products. 

Nature of the Analytical Methods Employed. — Since usually only a 
small number of the samples submitted are adulterated, the analyst should, 
as quickly as possible, separate the pure from the impure, so as to con- 
centrate his attention on the latter. The nature of the processes by 
which this is done varies with the foods. Experience soon enables one 
to judge much by even the characteristics of taste, appearance, and odor, 
though such superficial indications should be used with discretion. One 
or two simple chemical or physical tests may often suffice to establish 
beyond a doubt the purity of the sample, after which no further atten- 
tion need be paid to it. 

A sample failing to conform to the tests of a genuine food must be 
carefully examined in detail for impurities or adulterants. While in 
most cases usage or experience suggests the forms of adulteration peculiar 
to various foods, the analyst should be on the alert to meet new conditions 
constantly arising. His methods are largely qualitative, since technically 
he need only show in most cases the mere presence of a forbidden in- 
gredient, though for the analyst's own satisfaction 'he had best deter- 
mine the amount, at least approximately. 

In reporting approximate quantitative results in court, especially 
when they are calculated from assumed or variable factors, or when they 
are the result of judgment based on the appearance of the food under 

* U. S. Dept. of Agric, Ofif. of Sec, Circ. 19. 



FOOD ANALYSIS AND OFFICIAL CONTROL 5 

the microscope, the analyst should always be conservative in his figures 
by expressing the low^est or minimum amount of the adulterant, so as 
to give the defendant the benefit of any doubt. When exact standards 
are fixed by law, as in the case of total solids or fat in milk, for example, 
there is of course great necessity for preciseness in quantitative work. 

A full analysis of an adulterated food beyond establishing the nature 
and amount of the adulteration is entirely unnecessar}', and in most 
instances adds nothing to the strength of a contested case, as twenty 
years' experience in the enforcement of the food laws in Massachusetts 
has shown. 

The responsibility resting upon the analyst is not to be lightly con- 
sidered, when it. is realized that his judgment and findings constitute the 
basis on which court complaints are made, and the payment of a fine 
or even the imprisonment of the defendant may be the result of his report. 
Therefore he should be sure of his ground, knowing that his results are 
open to question by the defendant. Where court procedure is apt to be 
involved, a safe rule is for the analyst to consider himself the hardest 
person to convince that his tests are unquestionable, making every possible 
confirmatory test to strengthen his position and consulting all available 
authorities before expressing his opinion; and finally, after being fully 
convinced that a sample is adulterated, and having so alleged, let him 
adhere to his statements and not waver in spite of the most rigid cross- 
examination to which he may be subjected. 

While each state or municipality has its own peculiar code of regula- 
tions and restrictions concerning the duties of the analyst and other officials, 
these rules are in the main very similar. For instance, it is usually neces- 
sary, excepting in the case of such a perishable food as milk, for the analyst 
to reserve a portion of a sample before beginning the analysis, which 
sample, in the event of proving to be adulterated, shall be sealed, so that 
in case a complaint is made against the vendor, the sealed sample may, 
on application, be delivered to the defendant or his attorney. 

Adulteration of Food. — Except in special cases a food in general is 
deemed to be adulterated if anything has been mixed with it to reduce 
or lower its quality or strength; or if anything inferior or cheaper has 
been substituted wholly or in part therefor; or if any valuable constituent 
has been abstracted wholly or in part from it ; or if it consists wholly or 
in part of a diseased, decomposed, or putrid animal or vegetable sub- 
stance; or if by coloring, coating, or otherwise it is made to appear of 
greater value than it really is; or if it contains any added poisonous 



6 FOOD INSPECTION AND ANALYSIS. 

ingredient. These provisions briefly expressed are typical of the general 
food laws adopted by most states and by the government, though the 
verbiage may differ. Laws covering compound foods and special foods 
vary widely with the locality. As to the character of adulteration, nine 
out often adulterated foods are so classed by reason of the addition of 
cheaper though harmless ingredients added for commercial profit, rather 
than by the addition of actually poisonous or injurious substances, though 
occasional instances of the latter are found. 

Authentic instances of actual danger to health from the presence of 
injurious ingredients are extremely rare, so that the question of food 
adulteration should logically be met largely on the ground of its fraudu- 
lent character. Indeed the commoner forms of adulteration are restricted 
to a comparatively small number of food products, the most staple articles 
of our food supply, such as sugar and the cereals, eggs, fresh meat, fresh 
vegetables and fruit being less often subject to adulteration. 

Misbranding.—Under the federal food law and the laws of many of 
the states misbranding constitutes an offense as well as adulteration. By 
misbranding is meant any untrue or deceptive statement or design on the 
label of a food package, either regarding the nature of the contents, or of 
the place of manufacture or name of manufacturer. One of the com- 
monest forms of misbranding consists in the incorrect statement of weight 
or measure. Extravagant and untrue claims as to nutritive value have 
hitherto constituted a frequent form of misbranding. 

A Typical System of Food Inspection. — The efficiency of a system of 
public food inspection is greatly enhanced if the business part of the 
work, including the bookkeeping and attending to the outside public, 
be done wholly through some person other than the analyst, as, for example, 
a health officer, to whom the collectors of samples and the analyst 
may report independently as to the results of their work, and whose 
duty it is to determine what shall be done in cases of adulteration. 
In this way the analyst knows nothing of the data of collection 
nor the name of the person from whom the sample was purchased, 
so that he can truthfully state in court that his analysis was un4 
biased. 

Suppose, for example, that three collectors are employed to purchase 
samples of food for analysis, their duties being to visit at irregular intervals 
different portions of a state or municipality. Each collector keeps a book 
in which he enters all data as to the collection of the sample, includ- 



FOOD AN.\LYSIS AND OFFICIAL CONTROL. 




Fig. I.— Inspectors' Lockers. Insuring safe legal delivery of samples collected by Inree 
inspectors. Each locker has a door in the rear accessible, from an anteroom, to the in- 
spector holding key to that locker only. 



FOOD INSPECTION AND ANALYSIS. 




&i)o 



FJD 




Fio. 2. — Inspectors' Lockers. Front View. The lockers are accessible to the analyst in the 
laboratory bv a single sUding-sash front, provided with a spring lock. The removable 
sliding-racks are convenient for returning clean sample bottles. 



FOOD ANALYSIS AND OFFICIAL CONTROL. 9 

ing the name of the vendor, assigning a number to each sample, which 
number is the only distinguishing mark for the analyst. One collector 
may use for this purpose the odd numbers in succession from i to 9999, 
the second the even numbers from 2 to 10,000, while the third may use 
the numbers from 10,000 up. Each of the two former would begin with a 
lettered series, as, for instance, A, numbering his samples lA, 3 A, 5 A, 7 A, 
etc., or 2A, 4A, 6A, etc., till he reached 10,000, then beginning on series 
B and so on. If the analyst is to be kept in ignorance of the brand or 
manufacturer in the case of package goods, the collector must remove 
from the original package sufficient of the sample for the needs of the 
analyst, and deliver it to the latter in a plain package, bearing simply the 
name under which the article was sold and the number. Such precau- 
tions are, however, not always practicable and depend largely on local 
regulations. The analyst reports the result of the analysis of each sample 
with the number thereof on a library card, with appropriate blanks both 
for data of analysis and for data of collection, the latter to be filled by 
the collector from his book after the analyst has handed in the card with 
the data of analysis. This system of recording and reporting analyses 
has been successfully used for years by the Department of Food and 
Drug Inspection of the Massachusetts State Board of Health. 

Legal Precautions. — The laboratory of the public analyst should 
preferably be provided with a locker for each collector, to which access 
may be had only by that collector and the analyst, so that in the absence 
of the latter, or when circumstances are such that the samples cannot be 
delivered to him personally, there may be such safeguards with respect 
to lock and key as to leave no question in the courts as to safe delivery 
and freedom from accidental tampering. With such a system it is un- 
necessary for the collector to place under seal the various samples sub- 
mitted for analysis. Unless such lockers or their equivalent are employed, 
it is best to carefully seal all samples. 

Such a system of lockers for use with three collectors is shown in 
Figs. I and 2. The same careful attention should afterwards be given to 
keep the specimens in a secure place both before and during the process 
of analysis, and to label with care all precipitates, filtrates, and solutions 
having to do with the samples, especially when several processes are 
being simultaneously conducted, in order that there may be no doubt 
whatever as to their identity. The importance of precautions of this 
kind in connection with court work can hardly be too strongly emphasized. 



10 FOOD INSPECTION AND ANALYSIS. 

Practical Enforcement of the Food Law. — In the case of foods actually 
found adulterated, there are three practical methods of suppressing their 
further sale, viz., by publication, by notification, and by prosecution. These 
may be separately employed or used in connection with each other, accord- 
ing to the powers conferred by law on the commission, board, or official 
having in charge the enforcement of the law, and according to the dis- 
cretion of such official. 

Publication. — Under the laws of some states, the only means of pro- 
tecting the people lies in publishing lists of adulterated foods with their 
brands and manufacturers' names and addresses in periodical bulletins 
or reports. Sometimes it is considered best to publish for the informa- 
tion of the pubHc lists of unadulterated brands as well, and, again, it is 
held that only the offenders should thus be advertised. 

Such pubhcation, by keeping the trade informed of the blacklisted 
brands and manufacturers, certainly has a decidedly beneficial effect 
in reducing adulteration, and involves less trouble and expense than 
any other method. It is obviously an advantage, however, in addition 
to this to be able in certain extreme cases to use more stringent methods 
when necessary. 

Notification and Prosecution. — The adulteration of food is best held 
in check in localities where under the law cases may be brought in court 
and are occasionally so brought. The mere power to prosecute is in 
itself a safeguard, even though that power is not frequently exercised. 
Under a conservative enforcement of the law, actual prosecution should 
be made as a last resort. Neither the number of court cases brought 
by a food commission nor the large ratio of court cases to samples found 
adulterated are criteria of its good work. Except in extreme cases, 
it is frequently found far more effective to notify a violator of the law, 
especially if it is a first offense, giving warning that subsequent infraction 
will be followed by prosecution. Such a notification frequently serves 
to stop all further trouble at once and with the minimum of expense. 
Instances are frequent in Massachusetts where, by such simple notifica- 
tion, widely distributed brands of adulterated foods have been immediately 
withdrawn from sale. 

Massachusetts was the first of all the states to enact pure-food legisla- 
tion, and since the year 1883 has had a well-established system of 
inspection, prosecuting cases under its laws through the Food and Drug 
Department of the State Board of Health. Cases are brought in court 
with practically no expense for legal services. Complaints are entered by 



FOOD ANALYSIS AND OFFICIAL CONTROL. 11 

the collector, or, as he is termed, inspector, who makes complaint not in 
his official capacity, but as a citizen who under the law has been sold a 
food found to be adulterated, and who is entitled to conduct his own 
case, which he does with the aid of the analyst and such other witnesses 
as he may see fit to employ. Experience is readily acquired by the inspector 
in conducting such cases in the lower police or municipal courts, where 
they are first tried, and years ago the services of legal counsel in Massa- 
chusetts were dispensed with as superfluous. Where such a practice is 
in vogue an intelligent inspector must of course be chosen with reference 
to his ability to do this court work. The food laws are few and simple, 
as are also the court decisions rendered under them, so that it is no great 
task for the inspector to become much more familiar with them than the 
average general lawyer whom he meets in court and who not infrequently 
consults the inspector for information regarding these laws. 

Statistics in the annual reports of the Massachusetts Board show 
with what uniform success these trials have been conducted. While 
more often settled in the lower courts, occasional appeal cases are car- 
ried to the superior courts, where the services of the regular district attor- 
ney are of course availed of in prosecuting the case. 

Such a system as the above, while admirable for a state or city after 
long experience in the enforcement of food laws in the courts, is obviously 
impracticable with newly established systems of state food inspection. 



CHAPTER II. . 
THE LABORATORY AND ITS EQUIPMENT. 

Location.— The selection of a location for a food laboratory cannot 
always be made solely with reference to its needs and its convenience, 
but it is more often subject to economic conditions beyond the analyst's 
control. Under very best conditions, such a laboratory should be situated 
in a building designed from the start exclusively for chemical or biological 
and chemical work. Almost any well-Hghted rooms in such a building 
can be readily adapted for the purpose. When, however, as is frequently 
the case, rooms for such a laboratory are provided in municipal, govern- 
ment, or office buildings, in which for the most part clerical work is done, 
the problem of adequately utilizing such rooms so that they may not 
at the same time prove offensive to or interfere with the comfort of other 
occupants of the building is sometimes difficult. It is obvious that base- 
ment rooms in such a building, as far as ventilation is concerned, are less 
readily adapted for the requirements in hand than are those of the top 
floor, though, if the light is good and there are abundant and well-arranged 
ventilating-shafts, such rooms may be made to serve every purpose. In 
the basement one may most easily obtain water, gas, and steam, and 
dispose of wastes without annoyance to one's neighbors. When, how- 
ever, it is possible to do so, rooms on the top floor of an office building 
should be utilized for a food laboratory, for in such rooms the problems 
of Hghting, heating and ventilating are comparatively simple and may 
usually be solved without regard to other occupants. In such a case 
ample provision must be made, preferably through shafts which are 
readily accessible for water-, gas-, steam-, and soil-pipes passing down 
below. 

The actual equipment of the food laboratory depends of course largely 
on its particular purpose; and while it is manifestly impossible to do other- 
wise than leave the details to the individual taste and needs of the analyst. 

12 



THE LABORATORY AND ITS EQUIPMENT. 13 

modified by the means at his disposal, a few general suggestions regarding 
important essentials may prove helpful. These imply a fairly liberal 
though not extravagant outlay, with a view to saving both time and energy 
by convenient surroundings well adapted to the work in hand. 

Floor.— The best material for the floor of the working laboratory 
is asphalt. Such a floor is firm but elastic, is readily washed by direct 
application of running water, if necessary, and resists well the action of 
ordinary reagents. An occasional thin coating of shellac with lampblack 
applied with a brush gives the asphalt floor a smooth, hard surface and 
may be applied locally to cover spots and blemishes. 

Lighting. — The ideal arrangement is with benches for analytical 
work running north and south, the principal light being from south win- 
dows, and with benches for microscopes, balances, colorimeters, and 
standard solutions along the north wall where the north windows admit 
a soft light and never direct sunshine. 

FIXTURES. 

Ventilation by forced draft is a great convenience. For this purpose 
an exhaust fan driven by an electric motor and controlled in speed by 
a fractional rheostat is admirable. Such a fan would best be located 
in a small closed compartment or closet near the centre of the series of 
rooms designed to be ventilated by it, and this closet should have directly 
over the fan an outlet-shaft passing through the roof of the building. 
With such a system, a series of branching air-ducts should radiate from the 
fan closet, conveniently arranged either above or along the ceiling and 
communicating with the various hoods, closets, and rooms near the top. 

Benches. — The working benches should have wooden or glazed tile 
tops. White glazed tile, if properly laid, furnish a very clean, sanitary, 
and resistant surface, besides being often convenient for color tests. If 
laid on a plank surface, cement should not be applied directly, as it swells 
the wood before drying out and results in a loose and often uneven surface. 
Cement may be avoided altogether and the tiles after first soaking in oil 
may be laid in putty directly on the wood. Tiles may be laid in cement 
by first covering the plank surface with cheap tin plate, overlapping the 
edges and securing by tacks. This prevents swelling of the wood. The 
tin may be covered to advantage with cheap paint. The tiles may then 
be embedded in a layer of cement spread over the tin surface. 

Soft encaustic glazed tiles commonly used for wall finish are not as 



14 FOOD INSPECTION AND ANALYSIS. 

effective as hard floor tiles specially glazed, since the former crackle and 
lose color when subjected to heat. A suitable material for the top of the 
titration bench is opal plate glass with a polished surface. Jet-black plate 
glass with a honed surface is admirably suited for the microscope 
table. 

When wooden bench tops are used they may be treated to advantage 
by staining with the following solutions: 

Solution I. loo grams of anilin hydrochloride, 40 grams of ammonium 
chloride, 650 grams of water. 

Solution 2. 100 grams of copper sulphate, 50 grams of potassium 
chlorate, 615 grams of water. 

Apply solution i thoroughly to the bare wood and allow it to dry; then 
apply 2 and dry. Repeat these applications several times. Wash with 
plenty of hot soap solution, let dry and rub well with vaseline. It is claimed 
that wood so treated is rendered fire-proof and is not acted on by acids and 
alkalies. When the finish begins to wear, an application of hot soap solu- 
tion or vaseline will bring back the deep black color. 

Gas and water outlets, sinks and waste pipes should be conveniently 
arranged, while the space beneath the benches should be utilized for drawers 
and cupboards. A clear bench width of 24 inches is ample for most 
work; if wider there is a temptation tc allow apparatus to accumulate at the 
back. At the back of the bench and within easy reach, a raised narrow 
shelf should be provided to be used exclusively for common desk reagents. 
This again should not be so wide as to allow the accumulation of useless 
bottles. A narrow raised guard or beading at the edge of the reagent shelf 
prevents the bottles from accidently slipping off. 

Hoods. — Closed hoods with sliding sash fronts are almost indispensable. 
These hoods should be directly connected with the ventilating shafts or 
pipes, or with the air-ducts that radiate from the exhaust-fan closet, when 
such a system is provided. Gas outlets inside the hoods are neces- 
sary. 

When there is a good draft, either natural or forced, a hooded top 
over the working bench, such as that shown in Fig. 3, is quite as efficient 
as a closed hood for most purposes. This is best made of galvanized 
iron, painted on the outside and treated on the inside with a preparation 
of graphite ground in oil. Here are best carried out all the processes 
involving the giving off of fumes and gases, which, if the ventilation is 
efficient, should pa^s directly up the flues and not come out in the room. 



THE LABORATORY AND ITS EQUIPMENT. 15 

Sinks and Drains. — The sinks should preferably be o f iron or porce- 
lain. If iron, they should at frequent intervals be treated with a coat of 




Fig. 3. — Hooded Top of Galvanized Iron over Working-bench, Connected with 
\'entilating Air-ducts. 

asphalt varnish. A great convenience is a hooded sink (Fig. 4) in which 
foul- smelling bottles, or vessel? giving off noxious or offensive fumes 



16 



FOOD INSPECTION AND ANALYSIS. 



or gases, may be rinsed under the tap while completely closed in. Open- 
work rubber mats at the bottom of the sinks help to insure against break- 
age. Open plumbing of simplest design should be used, and a multi- 
plicity of traps should be avoided. Sinks may be variously located for 




Fig. 4. — A Hooded Sink. An injector-like arrangement of steam and cold-water pipes 
furnishes water of any desired temperature. 

convenience without regard to situation of soil-pipes, if the floor is thick 
enough to allow an open drain with sufficient pitch to flow readily. Such 
open drains are much more readily cleaned than closed pipes, and are 
best constructed by splitting a lead pipe and laying it in an iron box which 
is sunk into the floor. The edges of the lead pipe arc rounded over those 
of the box as in Fig. 5, filling the joints with hydraulic cement, and 
the top of the drain is covered by a series of readily removable iron plates 



THE LABORATORY AND ITS EQUIPMENT. 



17 



flush with the top of the floor. Waste-pipes from sinks, still-condensers, 
refrigerators, and various forms of apparatus involving flowing water may 
be led into this drain, holes being drilled in the iron cover for their insertion. 
Gas, Electricity, and Steam. — While formerly gas, made either in 
public or private plants, was the sole dependence for laboratory work, 
to-day gas, electricity, and steam are often on tap in the same laboratory, 
for some processes one and for others another giving the best results. 
If only one can be had, gas is usually the cheapest and most satisfactory, 
but in many office buildings only electricity is available as it may be im- 
practicable to pipe in gas from the city mains and against insurance regu- 
lations to make it on the premises from gasoline. Laboratories and 




Fig. 5. — Section of Open Drain-pipe in Floor, 
works remote from centers often have an abundance of home-generated 
electricity and steam, but no gas. 

Fortunately electrical heaters for almost every kind of laboratory 
apparatus, such as furnaces, drying ovens, evaporators, thermostats, 
Kjeldahl digestors, and stills, are obtainable, although somewhat expensive. 
An electric current is also of great value in carrying out electrolytic methods 
and in running motors for driving centrifuges, shaking apparatus, ven- 
tilating fans, air pumps, etc. Whenever in an electrically equipped lab- 
oratory a free flame is indispensable, which is rarely the case, alcohol 
or blue flame kerosene oil burners are fairly satisfactory. Steam, when 
available, may be used to advantage for boiling ether or benzine in con- 
nection with continuous fat-extraction apparatus, for furnishing the 
motive power for driving the Babcock centrifuge, for heating water-baths 
and hot closets, and, in connection with cold water, to furnish a supply 



18 



FOOD INSPECTION AND ANALYSIS. 



of hot water when wanted at the sink. The latter application is illus- 
trated in Fig. 4. 

Suction and Blast. — If the water-pressure is ample, both air-pressure 
and exhaust for blast-lamps, vacuum filtration, and other purposes are 
readily available through the agency of the various devices used in con- 
nection with the flow of water, as, for instance, the Richards pump. When 
however, the water pressure is insufficient, other means must be employed 
for furnishing these much-needed requisites. Fig. 6 illustrates a simple 




Fig. 6. — Portable Pressure- and Exhaust-pump Run by Electric Motor, Useful for 
blast-lamps, vacuum filtration, etc. 

and almost noiseless pressure and exhaust pump run by a i-H.P. electric 
motor, which with the pressure-equalizing tank and the appropriate 
connections are mounted on a light wheel truck, and readily movable 
to any part of the laboratory. By simply screwing the plug into an 
electric-light outlet, either suction or blast may be had at will, depending 
on the position of a knife-edge switch which determines the direction of 
the current. By means of a fractional rheostat the speed may be varied 
and the pressure thus controlled. 

APPARATUS. 
The laboratory is of course to be supplied with the usual assortment 
of test-tubes, flasks, beakers, evaporating and other dishes of porcelain, 
platinum and glass, funnels, casseroles, crucibles, mortars, burettes, 



THE LABORATORY AND ITS EQUIPMENT. 19 

pipettes, graduates, rubber and glass tubing, lamps, ring-stands and ' 

various supports, clamps and holders, the nature, number, and sizes cf 
which are determined by individual requirements. Special forms cf 
apparatus peculiar to certain processes of analysis or to the examination 
of special foods will be described in their appropriate connection. The 
following apparatus of a general nature may be regarded as indispensable 
for the proper fitting out of the food laboratory : 

Balances. — These should include (i) an open pan balance for coarse 
weighing, having a capacity up to i kilogram and sensitive to o.i gram, 
with a set of weights; and (2) an analytical balance, enclosed in a case, 
sensitive to .0001 gram under a load of 100 grams, with an accurate set 
of non-corrosive weights. The short-beam analytical balance is prefer- 
able for quick work, and as constructed by the best modern makers leaves 
nothing to be desired. 

Water-baths. — These are such an important accessory to food analysis 
that they should, if possible, be specially designed to meet the requirements, 
though the ordinary copper baths, supported on legs and designed to 
be heated by gas-burners, as kept in regular stock by the dealers, will 
sometimes serve the purpose. For nearly all moisture determinations the 
platinum dishes described on page 119 and the somewhat larger wine-shells 
of 100 cc. capacity are most used, and for this purpose the top of the 
bath should have plenty of openings of the right size for these. A very 
economical construction of bath admirably adapted for the food analyst's 
use is shown in Fig. 7, being the form employed by the writer. 

The size and number of openings are determined by the number of 
samples to be simultaneously analyzed. A steam coil within the body 
of the bath serves to boil the water. Fig. 7 also shows the hood for 
carrying off the steam and fumes, the sliding front of which is furnished 
with a hasp and a padlock, so that it may always be kept locked by the 
analyst whenever he is temporarily absent from the laboratory. This 
is a useful precaution, when the residues left thereon are from samples 
which are to form subjects for possible prosecution in court later. 

Steam, if available at all seasons of the year, or electric immersion 
coils furnish a ready means of heating the bath. In the absence of both 
steam and electricity, the bath must be boiled by gas burners. 

Drying-oven. — Water ovens heated by gas and steam ovens are com- 
monly used, although the drying cell seldom reaches a temperature above 
98° C. The electric oven shown in Fig. 8 obviates this difficulty, the 
regulator permitting of adjustment so that full 100°, as well as any de- 



20 



FOOD INSPECTION AND ANALYSIS. 



sired temperature can be attained. Fig. 9 shows an asbestos-covered, 
jacketed air-oven, heated by a gas burner, with an efficient form of gas- 
pressure regulator. 

Water-still. — An efficient still should be provided, capable of supply- 




FlG. 7. — Water-bath, Enclosed in Hood, with Sliding-sash Front. 

ing the laboratory with an ample quantity of pure water for analytical 
purposes. Fig. 10 illustrates a compact form of still, which is particu- 
larly economical in view of the fact that a single stream of inflowing cold 
water first serves to cool the condenser, and, rising, becomes vaporized 
in the boiler directly connected with the condenser at the top. This 
apparatus is capable of distilling six gallons of water in twelve hours. 

Universal Centrifuge. — This convenient apparatus merits a separate 
brief description, being useful for a wide variety of purposes, such as 



THE LABORATORY AND ITS EQUIPMENT. 



21 



breaking up ether and other emulsions, quickly settling out precipitates, 
and roughly estimating chlorides, sulphates, phosphates, etc., by the 
volume of the precipitate in graduated tubes. 




Fig. 8. — Freas Electrically Heated Drying Oven with Accurate Temperature Control. 

n 




Fig. 9. — Asbestos-covered Air-oven, with Gas-pressure Regulator. 
The centrifuge (Fig. 11) is inclosed within a cast-iron case and is 
driven by an electric motor concealed at the base. The vertical spindle 



22 



FOOD INSPECTION AND ANALYSIS. 



f;; provided with interchangeable heads carrying various forms of swinging 
holder? for tubes, bottles, beakers, and separatory funnels. Holders are 
obtainable for tubes ranging from 2 cc. to 200 cc. capacity, for Squibb's 
form of separatory funnel of 150 cc. capacity, and for graduated bottles 
such as are used in determining fat by the Babcock method and in meas- 




FiG. 10. — A Convenient Laboratory Water-still with Earthenware Receptacle, Provided with 

Faucet and Glass Gauge. 

uring precipitates, as for example, in Hortvet's method of estimating the 
amount of lead precipitate formed in solutions of maple sugar or syrup. 

The electrical machinery is entirely enclosed, thus obviating the danger 
of exploding mixtures of vaporized ether and air by sparking — a danger 
which always must be carefully guarded against in the food laboratory. 

The various types of centrifuges designed for the Babcock test (page 
124) may also be used for general work especially if fitted with inter- 
changeable heads carrying different forms of holders. 



THE LABORATORY AND ITS EQUIPMENT. 23 

Other special Apparatus. — The following list includes pieces which 
are more or less indispensable : 

Continuous Extraction Apparatus (Figs. 20, 21, and 22). 
Apparatus for Nitrogen Determination (Figs. 26, 27^, and 276). 
Apparatus for Distilling Various Food Products . 




Fig. II. — A Universal Electric Centrifuge. 

A Bahcock or other Milk-fat Centrifuge (Figs. 11 and 45). 

A Butyro Refractometer (Fig. 38). 

An Immersion Refractometer (Fig. 42). 

A Microscope and its Appurtenances (Chapter V). 

A Polariscope and its Accessories (Figs. 102, 103, and 104). 

Specific Gravity Apparatus (Figs. 14, 15, 16, and 17). 

Carbon Dioxide Apparatus (Fig. 71). 

Melting-point Apparatus (Fig. 93). 

Freezing-point Apparatus. 

Electrical Conductivity and Hydrogen Ion Concentration Apparatus 

(Chapter XXII). 
Marsh Arsenic Apparatus (Fig. 28). 
Electrolytic Apparatus (Fig. no). 
Separatory Funnels and Stand (Figs. 24 and 25). 

A Spectroscope, either of the direct-vision variety for the pocket, or 
the Kirschoff & Bunsen style on a stand. 

Spectroscope Cells, parallel-sided, for observation of absorption spectra. 



24 



FOOD INSPECTION AND ANALYSIS. 



A Photomicro graphic Camera and Appurtenances * (pp. 80. to 85). 

A Muffle Furnace, gas (Fig. 3), or, preferably, electric (Fig. 19). 

An Ehullioscope (Fig. 113). 

An Assay Balance, for weighing arsenic mirrors to o.oi mg. 

An Abbe Refractometer (Fig. 39). 

A Schreiner Colorimeter (Fig. 30). 

A Lovibond Tintometer (p. 67). 



REAGENTS. 

Under the appropriate methods are described the reagents for carrying 
out the processes treated of in this volume, together with their strength, 
mode of preparation when necessary, and other data. 
Reagents, especially those constantly employed, should 
be assigned to regular places on the shelves, and 
should invariably be kept in place when not in use. 

Among the standard solutions for volumetric work, 
none is more frequently of service in the food labora- 
tory than a tenth-normal solution of sodium hydrox- 
ide, and a large supply of this reagent, carefully 
standardized, should be at all times conveniently at 
hand. Besides being useful for standardizing tenth- 
normal solutions, it is constantly needed for deter- 
mining various acids in food products, such as milk, 
vinegar, butter, lime juice, cream of tartar, liquors, 
and many others. Time is well spent in carefully ad- 
justing this solution to its exact tenth-normal value, 
thus simplifying the calculation of results. A large 
stock bottle (say of two gallons capacity) containing 
the standard tenth-normal sodium hydroxide, is con- 
veniently mounted with a side-tube burette in con- 
nection, in some such manner as shown in Fig. 12. A 
small connecting side bottle contains a strong solution 
of sodium hydroxide through which the air that enters 
the large bottle is passed, thus depriving it of CO 2- In this manner the 
standard solution may readily be kept of unvarying strength for a year 
or more. 




Fig. 12. — Stock Bot- 
tle of Tenth-normal 
Alkali. 



* A photographic dark room is also necessary if photomicrographic work is to be done. 



THE LABORATORY AND ITS EQUIPMENT. 25 



EQUIVALENTS OF STANDARD SOLUTIONS. 

Decinormal Sulphuric Acid. One cc. is equivalent to 

Ammonia gas NHj 0.C017 granx 

Ammonia NH,OH 0.0035 

Ammonium carbonate (NHJ2CO3 0.0046 

(NHj^COg^zO 0.0057 

Calcium carbonate CaCOg o . 0050 

Calcium hydroxide Ca(OH)2 0.0037 

' ' oxide CaO o . 0028 

Lead acetate Pb(C2H30 2)2,31120 0.0189 

Magnesia MgO o . 0020 

Magnesium carbonate MgCOj 0.0042 

Nitrogen N 0.0014 

Potassium acetate * KCgHgO, o . 0098 

bicarbonate KHCO3 o.oioo 

bitartrate * KHC^H^e 0.0188 

carbonate K2CO3 0.0069 

citrate* KgCjHjOjjHgO 0.0106 

hydroxide KOH; 0.0056 

and sodium tartrate . KNaC^H^08,4H20 0.0141 

Sodium acetate NaC2H302,3H20 0.0136 

" benzoate * NaCyHjO, 0.0144 

" bicarbonate NaHC03 0.0084 

" borate Na2B^07,ioH20 0.0191 

" carbonate Na2C03 0.0053 

Na2C03,ioH20 0.0143 

" hydroxide NaOH 0.0040 

' ' salicylate * NaC7H503 o . 01 60 

Decinormal Sodium Hydroxide Solution. One cc is equivalent to 

Acid, acetic H,C2H302 0.0060 gram. 

" boric H3BO3 0.0062 

" citric H3CgH:,07,H20 0.0070 

" hydrobromic HBBr 0.0081 

" hydrochloric HCl 0.00365 

" hydriodic HI ■ 0.0128 

** lactic HC3H5O3 0.0090 

" malic C^HeOj 0.0067 

*' nitric HNO3 0.0063 

" oxalic H2C20^,2H20 0.0063 

„ , , . zT-or^ '^ ^° ^°^™ K.HPO.with I 

" phosphoric H..PO. -j , , : , , . r 0.0049 

^ ^ J 4 ( phenolphthalein ) ^^ 

,, ^^ ( to form KH,PO,with ) 

' phosphoric H,PO. i , , ~ * r 0.0098 

^ ^ •= M methyl orange ) ^ 

" sulphuric H2SO^ 0.0049 

" tartaric H2C^H^08 0.0075 

Potassium bitartrate KHC^H^Oj 0.0188 

Sodium borate i.... Na^B^Oj, loHjO o. 00955 

* To be ignited. 



26 FOOD INSPECTION AND ANALYSIS. 

Decinormal Iodine Solution. One cc. is equivalent to 

Arsenious oxide ASjOg 0.00495 gram, 

Potassium sulphite K2S03,2H20 0.0097 

Sodium bisulphite NaHSOj 0.0052 

" sulphite, Na2S03,7H20 0.0126 

" thiosulphate NajSjOjjSHjO 0.0248 

Sulphur dioxide SOj 0.0032 

Sulphurous acid HjSO-j 0.0041 

Decinormal Sodium Thiosulphate Solution. One cc. is equivalent to 

Bromine Br o . 0080 gram. 

Chlorine CI 0.00355 " 

Iodine I 0.01266 " 

Iron (in ferric salts) Fe 0.0056 " 

Decinormal Silver Nitrate Solution.* One cc. is equivalent to 

Ammonium bromide NH^Br o . 0098 gram. 

" chloride NH^Cl 0.00535 " 

Chlorine CI 0.00355 " 

Cyanogen (CN)2 0.0052 " 

Hydrocyanic acid HCN with indicator 0.0027 " 

< , TT-^xT { to formation of precip- [ 

" " HCN . ^ ^ f 0.0054 " 

( itate ' ^^ 

Hydrobromic acid HBr 0.0080 " 

Potassium bromide KBr 0.0119 " 

chloride KCl 0.00745 " 

" cyanide KCN with indicator 0.0065 " 

" KCN r°^°™^''''''°^P''"P'' 0.0130 " 

j itate i ■^ 

Sodium bromide NaBr 0.0103 " 

" chloride NaCl 0.00585 " 

Decinormal Potassium Bichromate Solution.! One cc. is equivalent to 

Ferrous carbonate FeCOj 0.0116 gram. 

Ferric oxide FcjOj 0.0080 '* 

Ferrous oxide FeO 0.0071 " 

" sulphate FeSO^ 0.0152 " 

" FeSO,,7H20 0.0278 " 

Iron (ferrous) Fe 0.0056 " 

Decinormal Potassium Permanganate Solution. One cc. is equivalent to 

Oxalic acid H2C20^,2H20 0.0063 gram, 

and to same weights for iron salts as given under N/io K2Cr20,. 



* Use potassium chromate solution as an indicator, or add till precipitate appears. 

+ Use a freshly prepared solution of potassium ferricyanide as an mdicator, applying a drop of titrated solu- 
tion to a drop of indicator on a white surface. 



THE LABORATORY AND ITS EQUIPMENT. 



27 



The following table from Talbot * shows the reactions of the com- 
mon indicators used in acidimetry: 



Indicator. 


Reaction with 
Acids. 


Reaction U^\^''> 
• . \ Carbonic 

Alkalies. Acid in Cold 

solution. 


Use with 

Carbonic 

Acid in Hot 

Solution. 


Use with 

Ammonium 

Salts. 


Use with 
Organic Acid. 


Litmus 


Red 

Pink 
Colorless 
Purple-red 
Purple -red 

Yellow 
Yellow 


Blue 
Yellow 
Pink 
Blue 
Blue 
Pink 
Red 


Unreliable 
Reliable 
Unreliable 
Unreliable 
Reliable 
Unreliable 
Unreliable 


Reliable 
Unreliable 
Reliable 
Reliable 
Reliable 
Reliable 
Reliable 


Reliable 
Reliable 

Unreliable 
Reliable 
Reliable 

Unreliable 
Reliable 


Relia"oi3 

Unreliable 

Reliable 

Unreliable ( ?) 

Unreliable 

Unreliable^ 

Reliable 


Methyl orange. . . 
Phenolphthalein. . 

Lacmoid 

Cochineal 

Rosolic acid 

Alizarine 



* Talbot, Quantitative Analysis, page 75. 
t Reliable wiih oxa'ic acid. 



CHAPTER III. 

FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, AND 
NUTRITIVE VALUE. 

Nature and General Composition. — Food is that which, when eaten, 
serves by digestion and absorption to support the functions and powers 
of the body, by building up the material necessary for its growth and 
by supplying its wastes. The raw materials that constitute our food- 
supply are not all available for nourishment, but often contain a propor- 
tion of inedible or refuse matter, which it is customary to remove before 
eating, such as the bones of fish and meat, the shells of clams and oysters, 
eggshells, the bran of cereals, and the skins, stones, and seeds of fruits 
and vegetables. The proximate components which make up the edible 
portion of food include in general water, fat, various nitrogenous bodies 
consisting chiefly of proteins, carbohydrates, organic acids, and mineral 
matter. Of these water is hardly to be considered as a nutrient, though 
it plays an important part in nearly all foods as a diluent and solvent. 
The fats, proteins, and carbohydrates all contribute in varying degree to 
the supply of fuel for the production of heat and energy. Besides this 
universal function, the fats and the carbohydrates serve especially to fur- 
nish fatty tissue in the body, while the proteins are the chief source of 
muscular tissue. 

Liebig's classification of foods into nitrogenous, or flesh formers, and 
non-nitrogeneons, or heat generators, is now no longer accepted as strictly 
logical, in view of the well-known fact that the nitrogenous materials, 
besides building up the body, aid in supplying the wastes and yielding 
energy, and may even be converted into fats or carbohydrates, while the 
non-nitrogenous aid in furnishing tissue growth in addition to serving as 
fuel. 

The Fat of Food.— Fats and oils consist essentially of the glycer- 
ides of the fatty acids, the characteristics of the various edible fats and 

28 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 29 

oils being treated under their appropriate headings elsewhere. Fat in 
human food is suppHed by milk and its products, by the adipose tissue of 
meat, and in slight extent by the oil of cereals and by the edible table 
oils. The term "ether extract" is sometimes used in stating the results 
of the analysis of foods and this includes other substances than fat which 
when present are extracted by ether, such as chlorophyl and other color- 
ing matters, lecithin, alkaloids, etc. 

The glycerides occurring in foods are of acids belonging in four series 
as follows, the value for 11 being in parentheses : 

A. Acetic Series (C„H2„02).— Butyric (4), caproic (6), caprylic 
(8), capric (10), lauric (12), myristic (14), palmitic (16), stearic (18), 
arachidic (20), behenic (22), and lignoceric (24). 

B. Oleic Series (C„H2„-202).— Hypogoeic (16), oleic (18), isooleic 
(18), rapic (18), and erucic (22). 

C. LmoLic Series (CnH2n-402).— LinoHc (18). 

D. LiNOLENic Series (C„H2„-602).— Linolenic (18). 

E. Clupanodonic Series (C„H2„-802).— Clupanodonic (18). 

Fats contain not only simple glycerides, consisting of glycerol com- 
bined with three equivalents of the same fatty acid, but mixed glycerides 
with two or three acids in the same molecule. Other substances present 
are free fatty acids, lecithin, cholesterol, phytosterol, sitosterol, coloring 
matter, and other matters in minute amount. 

Nitrogenous Compounds and their Classification — These 
substances may for convenience be grouped as follows : 

A. Proteins, B. Amino-acids, Amides, Amines, etc., C. Alkaloids, D. 
Nitrates, E. Ammonia, F. Lecithin, and G. Cyan Compounds. 
^ A. Proteins. — Occurrence. — Under the term proteins are included 
numerous bodies consisting, according to our present knowledge, essen- 
tially of combinations of a-amino-acids and their derivatives. Proteins 
in one form or another exist in nearly all natural foods both animal and 
vegetable, but are supplied chiefly by the flesh of meat and fish, by milk, 
cheese, and eggs, and in the vegetable kingdom by grain, seeds, nuts, 
and vegetables, especially the legumes. The proportion of crude protein, 
often designated merely as " protein," is commonly estimated by mul- 
tiplying by 6.25 the percentage of nitrogen found in the material anal- 
yzed. This is done on the assumption that all of the nitrogen present 
in the substance belongs to protein and that the protein contained 16 
per cent of nitrogen, neither of which assumptions is usually true, al- 
though for most purposes the results are sufficiently accurate. In certain 



30 FOOD INSPECTION AND ANALYSIS. 

cases, as for example, wheat flour and milk, special factors (5.70 and 6.38 
in the :ases :ited) are used. Methods depending on the separation of 
the proteins as such are used in special investigations, but these, with few 
exceptions, are not adapted for practical purposes. 

There is no marked distinction in chemical constitution between animal 
and vegetable proteins, although some of the types have as yet been found 
only in one or the other kingdom. The terms " proteids " or " albu- 
minoids " were formerly used generically as synonymous with " protein " 
to include all nitrogenous bodies of this group, but in 1908 a joint com- 
mittee on protein nomenclature of the American Physiological Society 
and the American Society of Biological Chemists recommended that the 
word " proteid " be abandoned; that " protein " be used to designate 
the entire group; and that the word "albuminoids" be restricted to a 
sub-group of proteins. A committee of the Physiological Society of 
England also made the same recommendation as to the use of the term 
protein. The classification and most of the definitions here given are 
those adopted by the American committee.* The examples in most 
cases were kindly furnished by Dr. T. B. Osborne. For further details 
the reader is referred to the works of Mathews,! Osborne,t Plimmer,§ 
and Jones, 1 1 also journal articles by Emil Fischer, Kossell> and their 
students. 

I. The Simple Proteins. — Protein substances which yield only a- 
amino acids or their derivatives on hydrolysis. 

Although no means are at present available whereby the chemical 
individuality of any protein can be established, a number of simple pro- 
teins have been isolated from animal and vegetable tissues which have been 
so well characterized by constancy of ultimate composition and uniformity 
of physical properties that they may be treated as chemical individuals 
until further knowledge makes it possible to characterize them more 
definitely. 

(a) Albumins. — Simple proteins soluble in pure water and coagulable 
by heat. 

Examples. — Seralbumin of blood and other animal fluids; lactalbumin 
of milk; leucosin of the seeds of wheat, rye, and barley; legumelin of legu- 
minous seeds. 

* Amer. Jour. Phys., 21, 1908, xxvii. 

t Physiological Chemistry, New York, 1916. 

X The Vegetable Proteins, London, 191 2. 

§ The Chemical Constitution of the Proteins, London, 1917. 

II Nucleic Acids, London, 1914. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 31 

Coagulation. — Animal albumins usually coagulate at about 75°; 
vegetable albumins at about 65°. 

Miscellaneous Reactions. — Very dilute acids precipitate albumins with 

the aid of heat. Nitrate of mercury (in dilute nitric acid) precipitates 

albumins from their solutions; also Mayer's solution acidified with acetic 

acid. They are precipitated by saturation with ammonium sulphate. 

These reactions are not, however, characteristic of the group. 

(b) Globulins. — Simple proteins insoluble in pure water, but soluble in 
neutral solutions of salts of strong bases with strong acids. 

Examples. — Myosin of muscle substance; legumin of leguminous seeds; 
amandin of almonds. 

Qualitative Tests. — Globulins are precipitated from their solution by 
dialysis or dilution. Albumins are not thus precipitated. 

(c) Glutelins. — Simple proteins insoluble in all neutral solvents, but 
readily soluble in very dilute acids and alkalies. 

Examples. — Glutenin of wheat is the only well defined protein of this 
group. 

(d) Prolamins. — Simple proteins soluble in relatively strong alcohol 
(70-80 per cent), but insoluble in water, absolute alcohol, and other 
neutral solvents. 

Examples. — Gliadin of wheat; zein of maize; hordein of barley. Found 
as yet only in the seeds of cereals. 

The use of appropriate prefixes will suffice to indicate the origin of 
compounds of sub-classes a, b, c, and d, as for example: ovoglobulin, 
myalbumin, etc. 

(e) Albuminoids. — Simple proteins which possess essentially the same 
chemical structure as the other proteins, but are characterized by great 
insolubility in all neutral solvents. 

Examples. — Keratins of hair, nails, hoofs, horn, feathers, etc.; elastin 
of connective tissues; collagen of connective tissues and cartilage; fibroin 
and sericin of raw silk. No albuminoids have yet been discovered in plants. 

Gelatin is usually regarded as an albuminoid but does not come strictly 
within the requirements of the above definition. It is an artificial deriva- 
tive of collagen and is formed from it by boiling with water or subjecting 
to steam under pressure. It is prepared from bones and other animal 
parts, and is insoluble in cold, but soluble in hot water. When the hot 
water solution containing one per cent or more of gelatin cools, it forms a 
jelly. By prolonged boiling the gelatinizing power is lost. Aqueous 
solutions are strongly laevo-rotary. 



32 FOOD INSPECTION AND ANALYSIS. 

Gelatin in common with most proteins is precipitated from its solution 
by mercuric chloride, picric acid, and tannic acid. It is readily distin- 
guished from soluble proteins, in that it is not precipitated from its solution 
by lead acetate, nor by most of the metallic salts that throw down proteins. 

(f) Histones. — Soluble in water and insoluble in very dilute ammonia, 
and, in the absence of ammonium salts, insoluble even in an excess of 
ammonia; yield precipitates with solutions of other porteins, and acoagu- 
lum on heating, which is easily soluble in very dilute acids. On hydrolysis 
they yield a large number of amino-acids, among which the basic ones 
predominate. 

Examples. — Thymus histone. Not found in plants. 

(g) Protamins. — Simpler polypeptides than the proteins included in 
the preceding groups. They are soluble in water, uncoagulable by heat, 
have the property of precipitating aqueous solutions of other proteins, 
possess strong basic properties, and form stable salts with strong mineral 
acids. They yield comparatively few amino-acids, among which the basic 
amino-acids greatly predominate. 

Examples. — Salmin, clupein, and other protamins of fish spermatozoa. 
Not found in plants. 

II. Conjugated proteins. — Substances which contain the protein 
molecule united to some other molecule or molecules otherwise than as a 
salt. 

(a) Nucleoproteins. — Compounds of one or more protein molecules 
with nucleic acid. 

Examples.— ThQ nucleins salmin nucleate and clupein nucleate. 

(b) Glycoproteins.— Compounds of the protein molecule with a sub- 
stance or substances containing a carbohydrate group other than a nucleic 
acid. 

Examples. — Mucins; ovomucoid; ovalbumin; ichthulin. 

(c) Phosphoproteins. — Compounds of the protein moiCcule with some 
yet undefined phosphorus-containing substance other than a nucleic acid 
or lecithins. 

Examples .—Casein of milk; vitellin of egg yolk. 

(d) Haemoglobins. — Compounds of the protein molecule with haematin 
or some similar substance. 

Example. — Oxyhaemoglobin of red blood corpuscles. 

(e) Lecithoproteins. — Compounds of theprotein molecule with lecithins, 
(lecithans, phosphatides). 

Examples. — Lecithalbumin ; lecithin-nucleovitellin. 



J 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 33 

III. Derived Proteins. 

1. Primary Protein Derivatives. — Derivatives of the protein mole- 
cule, apparently formed through hydrolytic changes which involve only 
slight altterations of the molecule. 

(a) Proteans. — Insoluble products which apparently result from the 
incipient action of water, very dilute acids or enzymes. 

Examples. — Edestan; blood fibrin; insoluble myosin. 

(b) Metaproteins. — Products of the further action of acids or alkalies, 
whereby the molecule is so far altered as to form products soluble in very 
weak acids and alkalies, but insoluble in neutral fluids. 

Examples. — Acid albumin; alkali albumin. 

This group will thus include the familiar "acid proteins" and "alkali 
proteins," not the salts of proteins with acids. 

(c) Coagulated Proteins. — Insoluble products which result from (i) 
the action of heat on their solutions, or (2) the action of alcohol on the 
protein. 

Examples. — Albumin coagulated by heat or alcohol. 

2. Secondary Protein Derivatives. Products of the further hydro- 
lytic cleavage of the protein molecule. 

(a) Proteoses. — Soluble in water, uncoagulated by heat, and precipi- 
tated by saturating their solutions with ammonium or zinc sulphate. 

As thus defined this term does not strictly cover all the protein deriva- 
tives commonly called proteoses, e.g. heteroproteose and dysproteose. 

Subdivision of the Proteoses. — According to the proteins from which 
they are derived the proteoses may be designated albumose, from albumin, 
globulose, from globulin, vitellose, from vitellin, caseose, from casein, etc. 

Proteoses are subdivided into proto-proteose , soluble in water (both cold 
and hot) or in dilute salt solutions, but precipitated by saturation with 
salt; hetero- proteose, insoluble in water, and deutero- proteose, soluble in 
water, but not precipitated by saturation with salt. 

Vegetable proteoses are sometimes called phyt-albumoses. 

Qualitative Tests. — Besides responding to the biuret reaction (p. 34) 
proteoses are precipitated by nitric acid, the precipitate being soluble on 
heating, but reappearing on coohng. 

Proto-proteose is precipitated from its solution by mercuric chloride 
and copper sulphate; hetero-proteose is precipitated by mercuric chloride, 
but not by copper sulphate. 

(b) Peptones. — Soluble in water, uncoagulated by heat, and not pre- 
cipitated by saturating their solutions with ammonium sulphate. 



34 FOOD INSPECTION AND ANALYSIS. 

Qualitative Tests. — Besides giving the biuret reaction, peptones are 
precipitated from their solution by tannic acid, picric acid, phosphomolybdic 
acid, and by sodium phosphotungstate acidified by acetic, phosphoric, 
or sulphuric acid. 

Peptones are the only soluble proteins not precipitated by saturation 
with ammonium sulphate. 

(c) Peptides. — Definitely characterized combinations of two or more 
amino-acids, the carboxyl group of one being united with the amino group 
of the other, with the elimination of a molecule of water. 

The peptones are undoubtedly peptides or mixtures of peptides, the 
latter term being at present used to designate those of definite structure. 

Qualitative Tests for Proteins. — Xanthoproteic Reaction. — Concen- 
trated nitric acid containing nitrous acid formed during standing added 
to a solution of a protein may or may not form a precipitate. It, however, 
produces a yellow coloration on boiling. Addition of ammonia in excess 
turns the precipitate or liquid yellow or orange; proteins in suspension 
also react. 

Milton's Reaction. — Millon's reagent is prepared by dissolving metallic 
mercury in twice its weight of concentrated nitric acid, diluting with an 
equal volume of water, and allowing to settle. When added to a protein 
solution it produces a white precipitate, which becomes jDrick-red on 
heating. Solid proteins give the red color by direct treatment. Sodium 
chloride prevents the reaction. Various organic substances are precipi- 
tated by Millon's reagent, but these precipitates do not turn red on heating. 

Biuret Reaction. — If a solution of a protein in dilute sulphuric acid be 
made alkaline with potassium or sodium hydroxide and very dilute copper 
sulphate be added, a reddish to violet coloration is produced, similar to 
that formed if biuret be treated in the same way, hence the name. An 
excess of copper sulphate should be avoided lest its color obscure that 
of the reaction. 

In solutions which are strongly colored this reaction is of little use 
unless modified as follows: A considerable quantity of the dilute copper 
sulphate solution is added to the solution made alkaline with a large excess 
of potassium hydroxide, and then solid potassium hydroxide is dissolved 
to almost complete saturation in the solution. The mixture is then shaken 
with about one half its volume of strong alcohol. On standing the alcohol 
separates as a clear layer or a violet or crimson color if proteins are present. 

B. Amino-acids, Amides, Amines, and Allied Products.— Under 
this head are included products derived from acids or bases, the radicles 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 35 

of which replace one or more hydrogen atoms in ammonia. The most 
common bodies of this class occurring in foods follow : 

I. AminO-ACIDS — The following are obtained by the hydrolysis of 
the different proteins: i. glycocoll; 2. alanine; 3. valine; 4. leueine; 
5. glyco-leucine, 6. iso-leucine, 7. serine, 8. cysteine, 9. aspartic acid, 10. 
glutamic acid, 11. arginine, 12. lycine, 13. cystine, 14. tyrosine, 15. phenyl- 
alanine, 16. proline, 17. oxy-proline, 18. histidine, 19, tryptophane. Of 
these, I to 13 inclusive belong to the aliphatic series, 14 and 15 to the 
carbocyclic series, and 16 to 19 inclusive to the heterocyclic series. 

II. Amides. — Asparagin occurs in the young shoots of asparagus, 
lettuce and other green vegetables, and marshmallow root. Glutamine 
occurs in seeds during sprouting. 

III. Amines. — Choline is found in meat, egg yolk, and certain fungi. 
Betaine is a constituent of beets, hops, and certain mollusks. Carnitine 
occurs in meat extract. 

IV. Creatine and Creatinine.— These are constituents of meat 
extracts. 

V. Purine Bases. — In the vegetable kingdom these are represented 
by the caffeine of tea, coffee, and cocoa , and the theobromine of cocoa, 
in the animal kingdom by xanthine, hypoxanthine, guanine, and adenine 
of meat and meat extracts. They are also classified with the alkaloids. 

C. Alkaloids. — This group is characteristic of certain drugs; in 
foods they are of infrequent occurrence. Aside from the purine bases 
caffeine and theobromine, the piperine and piperidine of pepper are 
the only common examples. 

D. Nitrates. — These occur mostly in growing parts of the plant 
and only in traces. 

E. Ammonia. — This occurs in ripened cheese of certain varieties and 
meat that is undergoing decomposition. 

F. Lecithin. — This is a phosphorized fat occurring in egg yolk and 
other animal and vegetable substances. 

G. Cyan Compounds. — The bitter cassava contains hydrocyanic 
acid. Cyanides and sulphocyanides (thiocyanates) are found in small 
amounts, in various foods. Common examples of sulphocyanides are the 
pungent principles of mustard and horse radish. Amygdalin of bitter 
almonds is a glucoside containing the cyan group. 

Carbohydrates and their Classification.— Of the total number 
of carbohydrates which have been described only a limited number occur 
in food products and of these a considerable number do not exist in the 



36 P^OOD INSPECTION AND ANALYSIS. 

original vegetable or animal substance, but are formed during manu- 
facture. 

A classification of the common food carbohydrates is given below. 
Descriptions of the more important individuals appear in chapters X 
and XIV. Other details will be found in the works of Armstrong,* and 
Browne,! as well as in special papers by Emil Fischer, Tollens, and their, 
students. 

I. Monosaccharides. — These, also known as simple carbohydrates, 
are either aldehyde alcohols (aldoses) or ketone alcohols (ketoses) with 
usually one carbonyl and one or more alcohol groups. One of the hydro- 
gens of the end group CHjOH may be replaced by an alkyl group, usu- 
ally methyl. The formulae of the ^forms are mirror images of the d- 
forms. 

(a) Dioses. — No representative of this group occurs in foods, but 
an example is here given to illustrate the simplest form of monosaccharide. 

Example. — Glycolose (CHjOH-CHO), prepared synthetically. 

(b) Methyl Dioses. — Example. — Dimethylglycolose 

(CH3.CHOH.COCH3), 

occurs in vinegar and other fermented products. 

(c) Trioses. — Example. — Dioxyacetone (CHsOH-CO-CHgOH), a 
ketose, is formed in various fermentation processes. 

(d) Tetroses. — No example in food products. 

(e) Methyl Tetroses. — Example. — Apiose 

(CH20HHOC(CH20H)CHOHCHO), 

a constituent of the glucoside apiin of parsley. 

(f) Pentoses (C5H10O5). — These sugars occur seldom and in only 
small amounts in foods, but are prepared from the corresponding pento- 
sans by hydrolysis. 

Aldoses. — Examples. — J-Arabinose 

(CH2OH • (HOCH) 2 • HCOH • CHO) ; 

/-arabinose (CH20H(HCOH)2-HOCH-CHO), a constituent of certain 
glucosides; /-xylose (CH^OH-HOCH-HCOH -HOCH -CHO); (/-ribose 
(CH20H-(HOCH)3-CHO), a constituent of various nucleic acids. 
Ketoses. — Little studied. 

* Simple Carbohydrates, London, 191 2. 

t Handbook of Sugar Analysis, New York, 191 2. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS. ETC. 37 

(g) Methyl Pentoses. — Examples. — Rhamnose 

(CH3 • CHOH HCOH • (HOCH) 2 CHO), 
occurs in various glucosides; fucose 

(CH3CHOH(HOCH)2.HCOHCHO), 
derived by hydrolysis of fucosan. 

(h) Hexoses (CoHioOe). 
"" Aldoses. — Examples. — (^-glucose or dextrose 

(CH.OH(HOCH),HCOHHOCHCHO), 
abundant in nature, forming with J-fructose invert sugar, occurs in nu- 
merous glucosides, formed by hydrolysis of starch, and is one of the chief 
constituents of commercial glucose; (/-mannose 

(CH2OH • (HOCH) 2 . (HCOH) 2 • CHO), 
found in plant juices, germinating seeds, and molasses; ^-galactose 
(CH30H-HOCH-(HCOH)2-HOCHCHO), a constituent of certain 
glucosides, occurs free in whey and germinating seeds; /-galactose 
(CH2OH HCOH (HOCH) 2 HCOH CHO); d, /-galactose or racemic 
galactose, identified in certain oriental food products. 
Ketoses. — Examples. — c?-Fructose or levulose 

(CH20H(HOCH)2HCOHCOCH20H), 
occurs v/ith (/-glucose in invert sugar; J-sorbose 

(CH.OHHCOHHOCHHCOHCO-CH^OH), 
formed by fermentation of the juice of the sorb apple; glutose, found in 
molasses. 

n. DiSACCHARIDES. — These yield on hydrolysis two monosaccharides. 
Their constitutional formulae have not been fully decided on. 

Examples. — Sucrose or common sugar (C12H22O11); maltose 
(C12H22O11) formed by the action of diastase on starch; lactose or milk 
sugar (Ci2H220ii-H20); trehalose or mushroom sugar (Cj 2H 2 20ii-2H20) 
melibiose (Ci2H220ii-2H20), formed by action of yeast on raffinose. 
Of these maltose, lactose, and melibiose are copper reducing. 

III. TRISACCHARIDES.— These yield on partial hydrolysis a monosac- 
charide and a disaccharide. 

Example. — Raffinose (Ci8H320i6-5H20), occurs in sugar beets, 
cotton seed, etc. 

IV. Tetrasaccharides.— These yield on partial hydrolysis a mono- 
saccharide and a trisaccharide. 

Kraw/'/e.— Stachyose (C24H4202r4H20), found in various roots and 
in ash manna. 



38 FOOD INSPECTION AND ANALYSIS. 

V. Polysaccharides.— This group includes the pentosans 
((C5H,s04)„-H20) and the hexosans ((C6Hio05)n-H20). The value of 
n is so large that the water may for practical purposes be ignored. For 
descriptions of the individual pentosans and hexosans see Chapter X. 

(a) Pentosans. — Examples. — Araban; metaraban; xylan. 
(b) Hexosans. — Examples. — Mannan; galactan; inulin; dextrin; 
starch; cellulose. 

Closely allied to the carbohydrates, if not actually belonging to them, 
are inosite (CjHijOe), occurring in muscular tissue, and peclose, found 
in green fruits and vegetables. 

The Organic Acids. — These acids are minor though important 
constituents of foods. From their conversion into carbonates within 
the body, they are useful in furnishing the proper degree of alkalinity 
to the blood and to the various other fluids, besides being of particular 
value as appetizers. They exist in foods both in the free state and as 
salts. Acetic acid is supplied by vinegar; lactic acid by milk, fresh meat, 
and beer; citric, malic, and tartaric acids by the fruits. 

Mineral or Inorganic Materials. — These substances occur in 
food in the form of chlorides, phosphates, and sulphates of sodium, potas- 
sium, calcium, magnesium, and iron, and are furnished by common salt, as 
well as by nearly all animal and vegetable foods. The inorganic salts are 
necessary to supply material for the teeth and bones, besides having an 
important place in the blood and in the cellular structure of the entire body. 

Fuel Value of Food. — In order to express the capacity of foods for 
yielding heat or energy to the body, the term fuel value is commonly used. 
By the fuel value of a food material is meant the amount of heat expressed 
in calories equivalent to the energy which we assume the body could obtain 
from a given weight of that food material, if all of its nutritents were 
thoroughly digested, a calorie being the amount of heat required to raise a 
kilogram of water i° C. This definition apphes to what is known as the 
large calorie, which is one thousand times as large as the small calorie. 
Large calories are meant wherever the term occurs in this volume. The 
fuel value, or, as it is sometimes called, ''heat of combustion," may be 
determined experimentally with a calorimeter, or may be calculated by 
means of factors based on the result of many experiments showing the 
mean values for protein, fats, and carbohydrates. 

The Bomb Calorimeter.'^ — This apparatus in its most approved form, 

* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 21, pp. 120-126. 



FOOD, ITS FUNCTIONS, PROXIMATE COMPONENTS, ETC. 



39 



Fig. 13, consists of a water-tight, cylindrical, platinum lined, Stcel bomb, 
adapted to hold in a capsule the substance whose heat is to be determined, 
y,nd containing also oxygen under pressure. This bomb is immersed in 
water contained in a metal cyHnder, which is in turn placed inside of 
concentric cylinders containing alternately air and water. The heat for 
igniting the substance is supphed by the electric current passing through 
wires to the interior of the bomb and acting upon a cleverly devised 
mechanism therein. The heat developed by the ignition is measured by 




Fig. 13. — Bomb Calorimeter of Hempel and Atwater 

the rise in temperature of the water surrounding the bomb, as indicated 
by a very delicate thermometer graduated to hundredths of a degree, 
certain corrections being made, as, for instance, for the heat absorbed by 
the metal of the apparatus. A mechanical stirrer serves to equalize the 
temperature of the water surrounding the bomb. 

The Respiration Calorimeter is a combustion apparatus on a large 
scale, of which a living human being or animal confined in a tight chamber, 
is a part. The food is carefully weighed and analyzed and the oxygen 
is supplied in known amount from a cylinder to replace that consumed 
by oxidation in the lungs. The water and carbon dioxide exhaled are 



40 FOOD INSPECTION AND ANALYSIS. 

absorbed in calcium chloride tubes and potash bulbs or their equivalents 
on a large scale while the excreta is collected, weighed, and analyzed. 
The heat produced is measured by delicate appliances. In the United 
States human calorimeters are maintained at the Carnegie Nutrition 
Laboratory, Boston, under the direction of F. G. Benedict and at The 
Department of Agriculture, Washington, under the direction of Langworthy. 
A calorimeter for farm animals is in operation at State College, Pennsyl- 
vania, by Armsby. 

Calculation of Fuel Value. — The bomb calorimeter is beyond the 
reach of many laboratories while the respiration calorimeter can be main- 
tained only in specially equipped institutions, hence the expression of 
fuel values by calculation is the most common method employed. For 
this the factors of Rubner are generally used, in accordance" with which 
the amount of energy in one gram of each of the three principal classes 
of nutrients are, for carbohydrates 4.1, for protein 4,1, and for fats 9.3. 
Expressed in pounds, each pound of carbohydrate or protein has a fuel 
value of i860 calories, while each pound of fat has a fuel value of 4220 
calories. 

For further details on the caloric value of foods and the science of 
nutrition the works of Jordan,* Lusk,t Sherman, J and Snyder § may be 
consulted. 

* The Principles of Human Nutrition, New York, 1914. 
t The Science of Nutrition, Philadelphia, 191 7. 
I Chemistry of Food and Nutrition, New York, 1918. 
§ Human Food, New York, 1916. 



.CHAPTER IV. 
GENERAL ANALYTICAL METHODS. 

Bxtent of a Proximate Chemical Analysis. — For purposes of studying 
the proximate composition of food for its dietetic value, it is nearly always 
necessary to make determinations of moisture, ash, fat, total nitrogen, and 
carbohydrates (when present), as well as of the fuel value. In some cases 
it may be desirable to proceed further, to make an analysis of the ash, for 
instance, to separate, at least into classes, the various nitrogenous bodies, 
especially in flesh foods, and perhaps to subdivide the starch, sugar, gums, 
and cellulose or crude fiber that make up the carbohydrates in the case of 
cereals, 

A.n analysis is considered complete whenever the purpose for which 
the examination has been made has been accomplished, and on that pur- 
pose depends solely the extent to which the various compounds present 
shall be subdivided and determined. Such a subdivision may be extended 
almost indefinitely. For example, a milk analysis may consist simply in 
the determination of the total solids and (by difference) the water. Again, 
it may be desirable to divide the milk solids into fat and solids not fat, 
and in some cases to carry the subdivision still farther and separate the 
solids not fat into casein, albumin, milk sugar, and ash. 

Determinations of one or more of the proximate components natural 
to food are frequently of great service in proving their purity or freedom 
from adulteration. For the latter purpose, especially in such foods as milk, 
vinegar, oils, and fats, the determination of specific gravity is also an 
important factor. Special methods of a peculiar nature are often neces- 
sary in the examination of particular foods, and such methods will be 
treated subsequently under the appropriate headings. In the present 
chapter only such general methods as are applicable to a large variety of 
cases will be discussed. 

Expression of Results of a Proximate Analysis. — However complete the 
division of the various proximate compounds or classes of compounds 

41 



42 FOOD INSPECTION AND ANALYSIS. 

which the analyst sees fit to make, the results of his various determina- 
tions in a proximate analysis are expected to aggregate about 100%. 
If every determination be directly made, the result will rarely be exactly 
100, but the precision of the work is apt to be judged by its approach 
to 100. 

It is often the custom to determine certain compounds or classes of 
compounds by difference. Thus in cereals moisture, proteins, fat, crude 
fiber and ash may be determined by the regular analytical methods, 
and by subtracting their sum from .100 the difference may be expressed as 
" nitrogen- free extract" or carbohydrates. It has long been customary 
in food analysis to calculate the protein by multiplying the total nitrogen 
by the factor 6.25, and on this basis analyses of thousands of animal and 
vegetable foods have been made. WTiile the figure thus obtained is an 
arbitrary one, being at best but a rough approximation of the amount of 
protein present, yet for many reasons there is much to commend this 
practice of reporting results. In the first place, in most cases it actually 
does approach the truth. Again, the nitiogenous ingredients of many foods 
are so numerous and varied, that for the every-day study of dietaries and food 
values it would be well-nigh impossible with our present knowledge to 
subdivide these compounds with any degree of accuracy, and especially 
with uniformity between different chemists, to say nothing of the time 
involved. 

From the fact that so many valuable analyses have 'already been 
expressed on the basis of NX 6.25 for protein, the advantage of comparison 
with the results thus recorded would seem to be in itself a good reason 
for continuing the practice, especially until a factor that gives better 
average results can be adopted. By recording the actual nitrogen found 
as well as the "protein," old results may at any time be recalculated 
under new conditions, if found desirable. 

In flesh foods, when carbohydrates are known to be absent, the total 
protein may conveniently be determined by difference. Rather more 
progress has been made in the separation of the nitrogenous compounds 
of meats than of the vegetables and cereals, though the methods are by 
no means accurate or uniform. 

Most of the recorded analyses of vegetable foods express the carbohy- 
drates as a whole without attempting to subdivide them, at least furthei 
than possibly to express the crude fiber or cellulose separately. A much 
more intelligible idea of the dietetic value of these foods would be gained 
by a further separation into starch and sugars. 



d 



GENERAL ANALYTICAL METHODS. 43 

Preparation of the Sample.— It is at the outset of the utmost importance 
in all cases that a strictly representative portion of the food to be examined 
should be submitted to analysis. All refuse matter, such as bones, shells, 
bran, skins, etc., are removed as completely as possible from the edible 
portion and discarded. 

If the composition of the entire mass cannot be made homogeneous 
throughout, it may be best to select from various portions in making up 
the sample for analysis, in order to represent as fair an average of the 
whole as possible. 

Finally the sample, if solid or semi-solid, should be divided as finely 
as possible, by chopping, shredding, pulping, grinding, or pulverizing 
according to its nature and consistency. 

For disintegrating such substances as vegetables and meats for analysis, 
the common household rotary chopping-machine is admirably adapted. 
For pulverizing cereals, tea, coffee, whole spices, and the like, the mortar 
and pestle may be used, or a rotary disk mill or spice-grinder. 

Specific Gravity or Density of Liquids.— Where formerly it was cus- 
tomary to compare the density of liquids with that of water at 4° C. (its 
maximum density) it is now more common to refer to water at 15.5° C. 
or 20° C, making the determination at that temperature. A common 
form, of expressing the temperature of the determination and the tempera- 
ture of the standard volume of water with which that of the substance is 
to be compared, is the employment of a fraction, the numerator of which 
expresses the temperature of the determination and the denominator 

that of the standard volume of water, as — ^o , ^ ^ s* ^ C* 

4 15-5 15-5 4° 
When extreme accuracy in the determination of density is required, the 
pycnometer or Sprengel tube should be employed. 

The Hydrometer. — This instrument furnishes the most convenient and 
ready means of determining the density of liquids where extreme nicety 
is not required. If well made and carefully adjusted, the hydrometer 
may be depended on to three decimal places, but before relying on its 
accuracy, it should be tested by comparison with a standard instrument, 
or with the pycnometer. 

The liquid whose density is to be determined is contained in a jar 
whose inner diameter should be at least f '' larger than that of the spindle- 

* LTnless otherOTse stated, all specific gravities in this volume are assumed to be expressed 

I? <:° 
on the basis of ^'-^ 

15-5° 



44 FOOD INSPECTION AND ANALYSIS. 

bulb, and the temperature of the hquid should be exactly 15.5° when the 
reading is taken. 

For best results for use with liquids of varying densities, the laboratory 
should be furnished with a set of finely graduated hydrometers, each 
limited to a restricted part of the scale, together with a universal hydrom- 
eter coarsely graduated, covering the entire range, to show by preliminary 
test which of the special instruments should be used. 

A convenient set of seven such hydrometers are graduated as follows: 
0.700-0.850, 0.850-1.000, 1. 000-1.200, 1. 200-1. 400, 1. 400-1. 600, 1.600- 
1.800, 1.800-2.000, while the universal hydrometer has a scale extending 
from 0.700 to 2.000. Another less delicate set of three only has one for 
liquids lighter than water and two for heavier liquids. Some instruments 
have thermometers in the stem. Others require a separate thermometer. 

The Westphal Balance (Fig. 14). — This instrument consists of a 
scale-beam fulcrumed upon a bracket, which in turn is upheld by a sup- 
porting pillar. The scale-beam is graduated into ten equal divisions. 
From a hook on the outer end of the beam hangs a glass plummet pro- 
vided with a delicate thermometer, the beam being so adjusted that when 
the dry plummet hangs in the air, the beam is in exact equilibrium, i.e., 
perfectly horizontal as shown by the indicator on its inner end. If the 
large rider be placed on the same hook as the plummet and the latter 
immersed in distilled water of the standard temperature at which the 
determinations are to be made (say 15.5° C), the scale-beam should 
again be in equihbrium if the instrument is accurately adjustedo As 
commonly made, the weight of the plummet including the platinum wire 
to which it is attached amounts to 15 grams, and the displacement of 
its volume to 5 grams of distilled water at 15.5° C, the normal temperature 
on which the determinations are based. Thus the unit (or largest) rider 
should weigh 5 grams, while the others weigh 0.5, 0.05, and 0.005 gram 
respectively. 

If, instead of distilled water, the plummet be immersed in the liquid 
whose density is to be determined, the position of the riders on the scale- 
beam, when so placed as to bring the same into equihbrium, and when 
read in the order of their relative size (beginning at the largest), indicates 
directly the specific gravity to the fourth decimal place. 

If the hquid is lighter than water, the large rider is first placed in the 
notch where it comes closest to restoring the equilibrium of the beam, 
but with the plummet still underbalanced. The rider next in size is 
then applied in a similar manner, and, unless equilibrium is exactly re- 



GENERAL ANALYTICAL METHODS. 



45 



Stored, the third and the fourth riders successively. If it happens that 
two riders should occupy the same position on the beam, the smaller 
is suspended from the larger. 

If the liquid is heavier than water, the method employed is the same 
except that one of the largest or unit riders is in this case always hung 
from the hook which supports the plummet, while the others cross the 




L 




J 


1 



Fig. 14. — The Westphal Balance. 

beam at the proper points. If carefully made and adjusted, the Westphal 
balance is capable of considerable accuracy. 

A delicate analytical balance can be used in place of the less carefully 
adjusted Westphal instrument, by hanging the Westphal plummet from 
one of the scale-hooks of the same, and employing a fixed support for the 
glass jar that holds the liquid in which the plummet is to be immersed. 
The support is so arranged that the scale-pan below it can move freely 
*vithout coming in contact with it. This arrangement is shown in Fig. 15. 

The Pycnometer, or Specific- gravity Bottle. — Fig. 16 shows the two 



46 



FOOD INSPECTION AND ANALYSIS. 



forms of pycnometer commonly made. The plain form has a ground- 
glass stopper with a capillary passage through it, the other has a fine ther- 
mometer connected with the stopper and a capillary side tube provided 
with a ground hollow cap. Both are made in different sizes to hold 
respectively lo, 25, 50, and 100 grams of distilled water at the standard 



•jSMiijr' 




O ^ 



o 




Fig. 15. — ^The Analytical Balance Arranged for Determining Specific Gravity witli the 

Westphal Plummet. 

temperature. It is convenient to have a counterweight for each pycnom- 
eter as fitted with its stopper, thus avoiding much trouble in calculation. 
The calculation of results is simplified also if the pycnometers are accurately 
constructed to contain exactly the weight of distilled water which they 
purport to contain at the standard temperature, but it is rather difficult to 
procure such instruments, especially of the form furnished with the ther- 
mometer. Most instruments hold approximately the amount specified, 
the exact net weight of distilled water which they hold at standard tem- 
perature being found by careful test and kept on record. In determining 
the density of a liquid, the pycnometer is carefully filled with it at a tem- 
perature below the standard, the stopper carefully inserted, and the bottle 
wiped dry. Care should be taken that the liquid completely fills the bottle 
and is free from air-bubbles. The net weight of the liquid is then taken 



I 



GENERAL ANALYTICAL METHODS. 



47 



on the balance, when the temperature has reached the standard (say 15.5° 
C), being careful to wipe off the excess of hquid that exudes from the capil- 
lary due to expansion. The net weight of the hquid is divided by that of 
the same volume of distilled water, previously ascertained under the same 
conditions at the same temperature, the result being the density of the 
liquid. 

The pycnometer with thermometer attachment is obviously susceptible 
of a greater degree of accuracy than the other form, since the temperature 
of the hquid, even though 15.5° C. at the start, soon rises. 




Fig. 16. — ^Types of Pycnometer. 

The writer prefers to use the pycnometer provided with the ther- 
mometer, but without the hollow cap that covers the capillary side tube, 
unless hquids hke strong acids are to be operated on, that might other- 
wise injure the balance. By keeping the liquid to be tested for some time 
in a refrigerator, it acquires a temperature of from 10 to 12° C. It is 
then transferred in the regular manner to the pycnometer and the ther- 
mometer-stopper inserted (but not the hollow cap) and the bottle wiped 
dry. There is ample time to adjust the balance- weights with extreme 
care while the temperature of the liquid is rising, leisurely wiping off 



48 FOOD INSPECTION AND ANALYSIS. 

at intervals with a soft towel the excess that exudes from the capillary 
tube, the final weight of the dry bottle and contents being made at the 
exact temperature of 15.5° C. 

In taking the tare or adjusting the counterweight of a specific-gravity 
bottle, the latter should be perfectly clean and dry. It had best be rinsed 
first with water, then with alcohol, and finally with ether^ all traces of the 
latter being removed by a current of dry air, or otherwise, before weighing. 
In making successive determinations of density of a number of different 
liquids with the same pycnometer, it is sufficient to rinse the bottle once 
with a little of the liquid to be tested before making each determination, 
when the various liquids are miscible. When the liquids are immiscible, 
the bottle should be carefully cleaned in the manner described in the 
previous paragraph before making each test. 

The Sprengel Tube. — The Sprengcl tube is a variety of pycnometer 
useful when only a small quantity of the liquid to be tested is available. 
It is susceptible of great accuracy. It consists of a 
U-shaped tube (Fig. 17), each branch of which termi- 
nates in a horizontal capillary tube bent outward. 
One of the capillaries, b, has a mark m thereon and 
has an inner diameter of about 0.5 mm. The 
diameter of the other capillary, a, should not exceed 
0.25 mm. The liquid at room temperature is as- 
pirated into the tube so as to fill it completely, the 
end b being dipped in the liquid while suction is 
applied at the end a. The tube is then placed in a 
beaker of water kept at the standard temperature, 
the beaker being of such size that the capillary 
ends rest on the edge. The temperature of the 
liquid in the tube may be assumed to be constant 
*tG. 17.— Sprengel Tube when there is no further movement due to contrac- 
for Determining Spe- tion in the larger capillary end, b. The meniscus of 
cific Gravity. ^-^^ liquid, when cooled, should not be inside the 

mark m, and is brought exactly to the mark by applying a piece of bibulous 
paper to the other end, a. If a drop or two of hquid has to be added, this 
may be done by applying to the end a sl glass rod dipped in the liquid. 
When exactly adjusted, the whole is wiped dry and quickly weighed, 
hung from the arm of the analytical balance. To avoid evaporation by 
contact with the air, the ends of the capillaries are sometimes ground 
to receive hollow glass caps not shown in the figure. 



^ 




GENERAL ANALYTICAL METHODS. 49 

Determination of Freezing Point—The Beckmann Apparatus^ consists 
of a cooling jar provided with a stirrer, an ordinary thermometer register- 
ing temperatures below zero, and a siphon for emptying, an air jacket, 
a freezing tube with a stirrer, and a Beckmann thermometer graduated 
too.oi°C. 

The reservoir in the top of the Beckmann thermometer is for a reserve 
supply of mercury. If the capillary tube contains so much mercury 
that the top of the column when cooled to the freezing point is not within 
the scale, by gently tapping a portion may be made to drop into the reser- 
voir; if it contains too little a portion may be added in the same manner 
after inverting the thermometer. 

Process.— Fla.ce an amount of the sample in the freezing tube sufficient 
to cover the thermometer bulb and cool in the cooling jar, containing a 
mixture of crushed ice and salt sufficient to produce a temperature several 
degrees below zero, until the mercury column ceases to fall and begins 
to rise. Then quickly transfer the freezing tube to the ah- jacket and 
continue the cooling, with gentle stirring, until the mercury column remains 
constant. Read the temperature with the aid of a lens. Determine the 
reading for distilled water in the same manner. The difference between 
the two readings is the freezing point of the sample. 

Keister f in the examination of milk recommends as a check removing 
the freezing tube, after taking each reading, warming with the hands or 
in water at 40° until the contents melt, and repeating the cooling. He 
also emphasizes the necessity of controlling the supercooling within narrow 
limits— from 1° to 1.2° for the apparatus used by him. 

Determination of Moisture.— This is usually calculated from the 
loss in weight at the temperature of boiling water. Platinum dishes 
(Fig. 51) are well adapted for the drying as the residue can be ignited 
for the determination of ash. If only the moisture is desired, dishes of 
other metals or glass weighing bottles may be used. Caps for wide- 
mouthed bottles made of tinned lead are convenient and can be thrown 
away after using. Viscous substances are best spread over asbestos or 
sand to hasten the drying. 

Some materials must be heated above 100° C, while certain saccharine 
products are dried at 70° C. in vacuo to avoid decomposition. If alcohol, 
acetic acid, essential oils, or other volatile substances are present the loss 
includes these as we ll as moisture. As the water or steam oven seldom 

* Zeits. physik. Chem., 2, p. 638. 

t Jour. Ind. Eng. Chem., 9, 191 7, p. 862. 



60 



FOOD INSPECTION AND ANALYSIS. 



attains a temperature above 98°, the loss sustained in these is, strictly 
speaking, at the " temperature of boiling water." Figs. 8 and 9 show 
electric and gas ovens for heating at full 100°. Benedict has shown that 
certain materials can best be dried at room-temperature over sulphuric 
acid in vacuo. Trowbridge * has shortened this process in the case of 
meat, by gently agitating the desiccator during the drying. 




Fig. 18. — Apparatus for Drying in Hydrogen. 



Drying in Hydrogen. — Fig. 18 shows the apparatus devised by Win ton f 
for drying cereal products, legumes, cattle foods, etc.. The material is 
weighed out on a watch glass and transferred to the drying tube (G), 
wisps of cotton, too small to contain an appreciable amount of moisture, 
being used at both ends to prevent mechanical loss. The hydrogen is 
purified by passing through sodium hydroxide solution {A) and dried by 
sulphuric acid in the jar (B). The acid drops over the glass beads into 
the chamber at the bottom of the jar where the gas bubbles through it 
before passing out over the beads. A siphon automatically removes the 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 219. 
t Conn. Agric. Exp. Sta., Rep. 1889, p. 187. 



GENERAL ANALYTICAL METHODS. 



51 



excess of acid. The drying tubes pass through the copper tubes of the 
water oven and are fitted at the posterior ends with capillary exit tubes 
of 0.5 mm, bore, thus creating a slight pressure and insuring even dis- 
tribution of current. When the drying is begun the exit tubes should be 
within the copper tubes to avoid stoppage of the current by condensed 
moisture, but later they should be pushed out, as m the cut, and each 
tested by lighting. 

Determination of Ash.— The residue from the determination of moisture 
or else a new portion, is burned at 
a very faint red heat until white or 
gray, cooled in a desiccator and 
weighed. A flat-bottomed platinum 
dish is most convenient for the pur- 
pose. Platinum, however, is at- 
tacked by free chlorine, bromine, 
and iodine, sulphur and phosphorus, 
sulphates and phosphates with re- 
ducing agents, all sulphides, sodium 
or potassium hydroxide, nitrate and 
cyanide, metals, and metallic com- 
pounds reduced in fusion, such as 
lead, tin, zinc, bismuth, mercury, 
arsenic, and antimony. In such 
cases porcelain must be used. 




Fig. 19.— Hoskins Electric Furnace. 



The degree of heat employed in ashing should be the lowest possible to 
insure complete oxidation of the carbon, so as to avoid driving off certain 
volatile salts that are sometimes present and that would be lost if the heat 
were too high. At a bright red heat potassium and sodium chloride are 
slowly volatilized, and calcium carbonate is converted into oxide; further- 
more alkali phosphates fuse about particles of carbon, protecting them 
from oxidation. To avoid overheating it is recommended not to allow 
the flame to impinge directly against the dish, but to carry out the burn- 
ing on a piece of asbestos paper supported on a triangle. The asbestos 
also serves to distribute the heat and to protect the dish from the injurious 
action of the direct flame on long heating. In order to burn off the last 
traces of carbon, a second piece of asbestos paper may be placed over the 
top of the dish, or the incineration may be completed in a gas or 
electric muffle furnace (Figs. 3 and 19). Heating should be continued 
till the carbon is all oxidized, which is in most cases indicated by a white 



52 FOOD INSPECTION AND ANALYSIS. 

ash. It is, however, sometimes impossible to obtain a perfectly white 
ash, but the appearance of the ash usually indicates when all the carbon 
has been burnt off. It is sometimes necessary to stir the contents of 
the dish with a stiff platinum wire from time to time during the ignition. 

Methods for the detection and determination of the various ash ingre- 
dients are described in detail in Chapter X. Such cases as are peculiar to 
certain foods, like the metallic impurities that occur in canned, bottled, 
and preserved foods under certain conditions, will be considered in their 
appropriate place. 

Extraction with Volatile Solvents. — Whenever it is necessary to 
exhaust a substance of its ether-soluble or alcohol-soluble ingredients, 
some form of continuous extraction apparatus is emplo}?ed with ad- 
vantage. 

Preliminary Drying. — In the case of cereal, legume, and oil-seed 
products, meats, etc., the portion of the material dried in hydrogen, in 
vacuo, or in contact with air in an ordinary oven, for the determina- 
tion of moisture, may be used for extraction. If volatile oil is present, 
as in spices, the drying must be performed at room temperature in a 
desiccator. 

Milk and other liquids are absorbed in a roll of bibulous paper, in 
asbestos, or in sand, previous to drying (Chapter VII). The evaporation 
may be carried on in shells of thin glass (Hoffmeister Schalchen) which 
are finally broken previous to extraction, or in tinned lead bottle caps 
which may be crumpled up and inserted in the extractor. 

The Soxhlet Extractor. — This apparatus is shown in Fig. 20. The 
substance to be extracted is subjected to successive treatment with freshly 
distilled portions of the solvent in the tube 5. Dry powders are con- 
tained in extraction thimbles of filter paper or in filters folded over the 
end of a flat-bottomed cylinder so as to form a cartridge; liquids, such 
as milk, previously dried in a paper coil or in a wad of asbestos, are extracted 
without a filter. The vapor from the solvent, boiling in the flask F, 
passes up through the side tube a' into the condenser C, where it is lique- 
fied and falls drop by drop on the substance. 

When the level of the solvent in the tube 6* reaches the top of the 
siphon the liquid drains off into the tared flask F, carrying with it what- 
ever it dissolves. The operation is automatically repeated, the sub- 
stance being successively extracted with freshly distilled portions of the 
solvent, which leaves behind in the flask F the material in solution. 

The heater employed should be a hot plate heated by steam, or, as 



GENERAL ANALYTICAL METHODS. 



53 



shown in Fig. 20, an electric stove, which may be provided with a frac- 
tional rheostat for varying the amount of heat. If neither of these is 
available the extraction flask may be rested on a piece of asbestos paper 




Fig. 20. — The Soxhlet Extractor with 
Electric Heater. 




-Johnson Extraction 
Tubes. 



supported by a lamp stand, the heat being supplied by an ordinary Bunsen 
burner. 

The degree of ebullition is so regulated as to allow the solvent to saturate 
the sample and siphon over into the flask F from six to twelve times an 
hour, the extraction being continued from two to six hours, or until all the 
ether-soluble material has been removed. Care should be taken also that 



54 FOOD INSPECTION AND ANALYSIS. 

the rate oi "boiling and the rate of condensation are so regulated that no 
appreciable loss of reagent occurs during the extraction. A strong smell of 
ether perceptible at the top of the condenser indicates a loss. The solvent 
is recovered at the end of the extraction by disconnecting the weighing 
flask at a time when nearly all of the solvent is in the part 5 and before 
it is ready to siphon over. The weighing-flask is then freed from all 
traces of the solvent by drying first on the water-bath and then in the 
oven, after which it is cooled in the desiccator and weighed, the difference 
between this and the first weighing representing the weight of the fat or 
ether extract. 

The Johnson Extractor. — This form of apparatus (Figs. 21 and 22) has 
the advantage of the Soxhlet extractor in that it is simpler and employs a 
much smaller amount of ether. The substance is contained in the inner 
tube of the extractor (Fig. 21), which is closed at the lower end by one 
thickness each of filter paper and cheese cloth, held tightly in place by 
means of a linen thread wrapped several times about the tube in the con- 
striction and tied in a fast knot. This inner tube properly prepared 
can be used over and over for extractions. The outer tube, also shown 
in Fig. 21, is of such a size that the inner tube fits loosely within it. A 
slight bulge on one side prevents trapping by means of the condensed 
solvent. The extraction flask is preferably of only 30 to 35 cc. capacity. 
It is attached to the extractor, as is also the extractor to the condenser 
tube, by means of a carefully bored cork stopper. For ordinary deter- 
minations of ether extract the outer tube should have an inside diameter 
of 26 mm. and the inner tube an outside diameter of 22 mm., only 8 to 
10 cc. of the solvent being required. If, however, large amounts of material 
(25 to 50 grams) are to be extracted, the diameters may be made 32 mm. 
and 28 mm. respectively and a larger amount of solvent employed. 

Where only a few extractions are made, the heating can be performed 
over (but not on) a metal plate heated by a Bunsen burner, and the conden- 
sation effected by an ordinary Liebig condenser. If, however, a considerable 
number of extractions are carried out, the set apparatus shown in Fig. 22 
will be found convenient and also economical of space. It may be attached 
to the wall or placed at the back of a working desk. The heating, as shown 
in the cut, is effected by means of two steam pipes, but some form of elec- 
tric heater answers equally well. The case with glazed door prevents the 
radiation of heat. At the top is shown the multiple condenser consisting 
of a copper tank with block tin tubes. Water is introduced at the left 
and carried off at the right. 



I 



GENERAL ANALYTICAL METHODS. 



55 



The solvent is best poured through the material, thus obviating in large 
degree the crawling of the extract. The door should be opened several 
times during the extraction and kept open for a few minutes for the pur- 
pose of rinsing down the sides of the tubes by means of the condensed 
vapors. 

Preparation of Solvents. — In taking the so-called ether extract, some- 
times reckoned as fat, the solvent employed is either ethyl ether or the 
cheaper petroleum ether. Whichever reagent is employed, certain pre- 
cautions are necessary for the purity of the reagent. If ethyl ether is 




Fig. 22. — Johnson Multiple Extraction Apparatus with Heating Closet and Condenser. 

used, it should be entirely freed from moisture and alcohol by first shaking 
with water to remove the larger portion of the alcohol, allowing it to 
stand for some time over dry calcium chloride, and then distilling over 
metallic sodium. The ether thus prepared should be kept till used with 
sodium in the container, the latter being somewhat loosely corked, to allow 
escape of the hydrogen formed. 

Petroleum ether is variously termed benzine, naphtha, or gasoline. It 
should be low-boiling, preferably between 35° and 50°, and it is always 
best to redistil it before using, in order to be sure it is free from residue. 
As to the choice of the two reagents for use in fat extraction, it may be 
said that ethyl ether is the solvent most used, but if a large number of 
determinations are to be made, the lower cost of petroleum ether is to 



56 



FOOD INSPECTION AND ANALYSIS. 





Fig. 23. — Fractionating-still, Arranged for Petroleum Ether. 



Fig. 24. — A Convenient 
Form of Separatory 
Funnel. 



GENERAL ANALYTICAL METHODS. 



57 



be considered. A convenient still for fractionating such substances as 
petroleum ether is shown in Fig. 23. 

Extraction with Immissible Solvents. — It is frequently necessary to 
dissolve out a substance from a liquid by shaking it with an immiscible 
solvent, as, for example, in the extraction of certain preservatives from 
aqueous or acid solutions with ether, petroleum ether, or chloroform. 
This can be done by shaking in ordinary flasks, but is attended by some 
difficulty and loss on decantation. A separatory funnel of the type shown 
in Fig. 24 is almost indispensible for this kind of extraction. The liquid 




Fig. 25. — Separatory Funnel Support. 



and solvent are transferred to the funnel, which is then stoppered and 
shaken. If the solvent is heavier than water, as in the case of chloroform, 
it is drawn off from beneath through the outlet-tube of the funnel, or, if the 
solvent is the lighter, as in the case of ether, the aqueous liquid lying 
beneath is first drawn off and finally the solvent is poured out through 
the top. If troublesome emulsions form when shaken, they may frequently 
be broken up by adding an excess of the solvent and again very gently 
shaking, or by careful manipulation with a stirring rod, or by centrifug- 
ing. If the solvent is ether, and an obstinate emulsion forms, it may 
frequently be broken by the addition of chloroform. Such a mixture of 
ether and chloroform sinks to the bottom and may be drawn -off as in the 
case of chloroform alone. 



58 FOOD INSPECTION AND ANALYSIS. 

A separatory funnel support, devised by Win ton, is shown in Fig. 25. 
It serves for holding the separatory funnels while drawing from one into 
another, and also as a support for ordinary funnels. The two shelves 
are adjustable by means of thumbscrews. The holes in these shelves 
are somewhat wider than the slots, so that the separatory funnels after 
being introduced through the latter drop into position and are held firmly 
while manipulating the stop-cock. 

Winton attaches all stop-cocks and stoppers to the funnel by means of 
small brass chains, thus preventing breaking and interchange of these parts 
during washing. 
' Determination of Nitrogen by Moist Combustion. — In thus determin- 
ing nitrogen, the organic matter is first decomposed by digestion with 
sulphuric acid and an oxidizer, the carbon and hydrogen being driven off 
as carbon dioxide and water respectively, while the nitrogen is converted 
into an ammonium salt, from which free ammonia (NH3) is later liberated 
by making alkaline. The ammonia is then distilled into an acid solution 
of known value and calculated by titrating the excess of acid. 

In the Kjeldahl process the oxidation is effected by means of a mercury 
compound, in the Gunning method, by potassium sulphate which forms 
the bisulphate with the acid. 

Neither method in its simplest form is applicable in the presence of 
nitrates; if these are present, a modification must be used. The Gunning- 
Arnold method (page 446) is employed for the determination of nitrogen 
in pepper, as the piperin is not completely decomposed by the usual 
processes. 

The Gunning Method. — Reagents: 

Standard alkah solution, N/io NaOH or NH4OH.* 

Pulverized potassium sulphate. 

Sulphuric acid, concentrated, free from nitrogen. 

Sodium hydroxide, saturated solution. 

Standard acid solution, N/io H2SO4 or HCl.* 

An indicator, cochineal solution (page 28). 

Granulated zinc, passing a i-mm. mesh. 

* Winton employs standard acid of such a strength that i cc. is equivalent to i% of 
nitrogen, working on a gram of material, and titrates back with standard alkali two cind 
one-half times weaker than the acid. In order to insure accurate readings, burettes of 
narrow bore (i cc.= 2.6cm.) are employed. The alkali burette is so graduated that a 
reading of i corresponds to 2.5 cc, thus allowing for the greater dilution. The advantage 
of this system is that the per cent of nitrogen is obtained by simply subtracting the alkali 
reading from the number of cc. of acid employed. 



GENERAL ANALYTICAL METHODS. 59 

The digestion and distillation are preferably carried out in the same 
flask, which should be pear-shaped with flat or round bottom and made of 
moderately thick Jena glass. A convenient size has the following dimen- 
sions: length 29 cm., maximum diameter 10 cm., tapering gradually to a 
long neck, which near the end is 28 mm. in diameter with a flaring edge. 
Its capacity is about 550 cc. 

If desired, the digestion may be conducted in a smaller hard-glass 
flask of about 250 cc. capacity and of the same shape as the above, 
and the distillation in an ordinary round-bottomed flask cf 500 cc. 
capacity. 

Introduce from 0.5 to 3.5 grams of the sample into the digestion-flask 
with 10 grams of potassium sulphate and from 15 to 25 cc. of concentrated 
sulphuric acid. The flask is inclined over the flame and heated gently 
for a few minutes "below the boiling-point of the acid till the frothing 
has ceased, after whic"h the heat is gradually increased till the acid boils, 
and the boiling is continued till the contents have become practically 
colorless or at least of a pale straw color. Wire gauze may be interposed 
between the flask and flame, but a triangle or a similiar support is to be 
preferred. 

The contents of the flask are then cooled, and, if the digestion has 
been conducted in the larger flask suitable also for distilling, is above 
recommended, 300 cc. of water are added and sufficient strong sodium 
hydroxide to make the contents strongly alkaline, using phenolphthalein as 
an indicator. If a separate flask is used for the distillation, the contents 
of the digestion-flask are transferred thereto with the water and the alkah 
added. A few pieces of granulated zinc should also be introduced, which 
by the evolution of gas prevents bumping and the sucking back of the 
distillate. The flask is then without delay connected with the con- 
denser, the bottom of which is provided with an adapter, dipping below 
the surface of the standard hydrochloric or sulphuric acid, a measured 
quantity of which is contained in the receiving- flask. The distillation is 
then continued till all the ammonia has passed over into the acid, this 
part of the operation requiring from forty-five minutes to an hour and 
a half. As a rule the first 250 cc. of the distillate will contain all the 
ammonia. 

The excess of acid in the receiving-flask is then titrated with standard 
alkali, and the amount of nitrogen absorbed as ammonia is calculated. The 
reagents, unless known to be absolutely pure and free from nitrates and 



^ 



60 



FOOD INSPECTION AND ANALYSIS. 



ammonium salts, should be tested by conducting a blank experiment with 
sugar, by means of which any nitrates present are reduced. Any nitrogen 
due to impurities should be corrected for. 

In purchasing sulpliuric acid for nitrogen determination it is important 
to specify that it be "nitrogen-free" as the so-called chemically pure acid 
often contains a considerable amount of nitrogen. 

Modification of Gunning Method to include Nitrogen of Nitrates. — In 
addition to the reagents used in the simpler Gunning method, sodium 
thiosulphate and salicyhc acid are required. 

A mixture of salicylic and sulphuric acids is made in the proportion of 
30 cc. of concentrated sulphuric to i gram of sahcyhc. From 30 to 35 cc. of 




Fig. 26.— Bank of Stills for Nitrogen Determination by Gunning Process. 

the mixture are added to the 0.5 to 3.5 grams of the substance in the di- 
gestion-flask, the flask is well shaken and allowed to stand a few minutes, 



GENERAL ANALYTICAL METHODS. 



61 



occasionally shaking. Then 5 grams of sodium thiosulphate are added, 
and 10 grams of potassium sulphate, after which the heat is applied, at first 
very gently and afterwards increasing slowly till the frothing has ceased. 
The heating is then continued till the contents have been boiicd practically 
colorless. From this point on, proceed as in the Gunning method. 

The Kjeldahl Method. — One gram of the air dry substance, or a propor- 
tionately larger amount of a moist or liquid substance, and 0.7 gram of 
mercuric oxide (or an equivalent amount of metallic mercury) are placed 




Fig. 27a. — Johnson Digestion Stand for Nitrogen Determination with Lead Pipe for Carrying 

off Fumes. 



in a 550-cc. Jena flask and 20 cc. of sulphuric acid added. The flask is 
placed in an inclined position over a Bunsen burner, and the mixture 
heated below boiling for 5 to 1 5 minutes or until the frothing ceases, after 
which the heat is raised until the mixture boils briskly. The boiling is 
continued until the liquid has become nearly colorless and for a half 
hour in addition. The lamp is then turned out, the flask placed in an 
upright position, and potassium permanganate slowly added with shaking 
until the solution takes on a permanent green or purple color. 

After cooling, 250 cc. of water are added, then 25 cc. of potassium 
sulphide solution (40 grams of the commercial salt in i liter of water), 
sufficient saturated sodium hydroxide solution to render the solution 
alkaline, and finally a few grains of granulated zinc, shaking the flask 
after each addition. Without delay connect with the distillation appa- 
ratus, and proceed as in the Gunning method. 



62 



FOOD INSPECTION AND ANALYSIS. 



Apparatus for Nitrogen Determination. — A bank of stills used by the 
author in nitrogen determination and in other processes is shown in Fig, 26. 

The digestion apparatus shown in Fig. 27a is that devised by Johnson, 
Winton, and Boltwood. The stand is of cast iron, with holes provided 
with three projections that support the flask. The lead pipe with holes 
for receiving the ends of the flasks serves to carry off the acid fumes. 
Sy has devised apparatus for sucking the fumes from the flask into water 
by means of a filter pump, thus dispensing with a hood. 




Fig. 2 7 J. — Johnson Distilling Apparatus for Nitrogen Determination. 

The Johnson distilling apparatus, with accessories by Winton, is 
hown in Fig. 27^. The distillation tubes, except for the glass traps and 
bulb receiver tubes, are of block tin, and are cooled in a copper tank filled 
with water. The receivers for the distillate are ordinary pint milk 
bottles. 

At the left are two bottles with suspended tubes for measuring the 
potassium sulphide and sodium hydroxide solutions. 

Determination of Ammonia. — A weighed quantity of the finely 
divided sample, treated with ammonia-free water and made alkaline with 
magnesium oxide free from carbonate, is distilled into a measured quan- 
tity of standard acid (tenth-normal hydrochloric or sulphuric acid) and 
the amount of ammonia determined by titration. 



GENERAL AJMALYTICAL METHODS. 63 

Determination of Protein Nitrogen. — Stutzer Method.^ — Boil 0.5-2.0 
grams of the sample, ground to pass a i-mm. mesh, with 100 cc. of 1% 
acetic acid in 95% alcohol, cool, filter, and wash by decantation with warm 
alcohol. Heat the insoluble matter in the beaker with 100 cc. of water 
for 10 minutes on a boiling water-bath with stirring, cool, and add copper 
hydroxide suspension (2% copper sulphate solution 'containing 0.05% of 
glycerol, precipitated with an excess of sodium hydroxide, washed by decanta- 
tion with water containing 0.5% of glycerol, and finally suspended in 10% 
glycerol) sufficient to contain 0.3-0.4 gram of copper hydroxide as deter- 
mined by evaporation and ignition. Allow to settle, collect on a paper, wash 
with water, and determine nitrogen in filter and contents. In the absence of 
alkaloids heat directly with water and precipitate with the copper reagent. 

Determination of Nitrogen in Amino Acids. — Van Slyke Method.-\ — 
This method has proved valuable in physiological investigations and 
is useful in food examination in special cases. The manipulation is quite 
simple, but the apparatus is somewhat expensive. For further details 
reference should be made to Van Slyke's original articles or Mathews' 
Physiological Chemistry. 

Determination of the Various Carbohydrates. — Under title of "Cereals" 
in Chapter X are given in detail methods for separation and determination 
of sugar, starch, dextrin, crude fiber, etc. 

Detection of Poisons. — Metallic impurities present in foods incidental 
to their preparation, or as adulterants, are considered under title of foods 
liable to such adulteration. The detection of highly toxic substances, 
such as arsenic, corrosive sublimate, and alkaloids, added with criminal 
intent, comes within the province of the medico-legal chemist or toxicologist 
and is beyond the scope of this work. The methods involved are fully 
described in the treatises of Autenrieth | and Blyth,§ only those for 
arsenic, which occurs also as an accidental impurity, being here considered. 

Detection and Determination of Arsenic. — Methods of Solution. — • 
Syrups, baking powders and other materials soluble in water or acid do 
not need preliminary treatment. Beer is treated as described in Chapter 
XV. Other methods of solution are as follows: 

I. Johnson-Chittenden-Gautier Method.\\ — This method is suitable 
for meat, vegetables, and the like, the proportion of acids used being 

* Jour. Landw., 29, 1881, p. 473. 

t D. D. Van Slyke, Jour. Biol. Chem., 12, 1912, p. 275; 16, 1913, p. 121; 23, 1915, p. 408. 

X Detection of Poisons and Strong Drugs, trans, by Warren, Phila., 1905. 

§ Poisons, their Efifects and Detection, London, 1906. 

II Amer. Chem. Jour., 2, 1880-81, p. 250. 



64 



FOOD INSPECTION AND ANALYSIS. 



varied to suit conditions. Heat at i5o°-i6o° C, in a porcelain dish, loo 
grams of the finely divided material with 23 cc. of pure concentrated 
nitric acid, stirring occasionally. When the mixture assumes a deep 
orange color, remove from the heat, add 3 cc. of pure concentrated sul- 
phuric acid, and stir while nitrous fumes are given off. Heat to 180° 
and add while hot, drop by drop, with stirring, 8 cc. of nitric acid, then 
heat at 200° till sulphuric fumes come off and a dry charred mass remains. 
Pulverize the mass, exhaust with hot water, filter, evaporate to small 
volume, take up in cold 20% sulphuric acid and treat by the modified 
Marsh or Gutzeit method. 

2. Sanger Method.'^ — Digest at room-temperature for some hours 
5 to 20 grams of the material in a casserole with about an equal bulk of 



\=- 




Fig. 28. — Marsh Apparatus for Arsenic. 

concentrated nitric acid, add 20 cc. of concentrated sulphuric acid and 
digest further at a gentle heat until the mixture begins to char. Add about 
2 cc. of nitric acid and heat until sulphuric fumes appear, repeating the 
addition of acid and heating until oxidation appears to be practically 
complete. Remove all nitric acid by dilution and evaporation to the 
fuming stage, then dilute with 4 volumes of water. At this point about 
twice the bulk of saturated sulphurous acid solution may be added and the 
evaporation repeated, thus reducing to the arsenious condition, but this 
is not usually necessary. 

Methods of Determination. — i. Marsh Test. — The apparatus (Fig. 28) 
consists of a generating flask with funnel tube, a U-tube containing cotton 
* Proc. Am. Acad. Arts, Sci., 26, 1891, p. 24. 



GENERAL ANALYTICAL METHODS. 



65 



moistened with io% lead acetate solution (to remove hydrogen sulphide), 
a calcium chloride drying tube, and a hard glass tube of 6 mm. bore, 
drawn down near the end to a uniform constriction 
about 4 cm, long and i mm. inside diameter and also at 
the very end to a narrow exit tube. The tube is sup- 
ported over a three-burner furnace the part in contact 
with the flame being wrapped with wire gauze. 

Introduce into the generating flask from 20 to 30 grams 
of arsenic-free stick zinc and a perforated platinum disk 
to form an electric couple. Stopper and add through 
the funnel tube 20% sulphuric acid sufficient to start the 
reaction and drive out all air. When danger of explosion 
is over heat the tube to bright redness. After running 
the current long enough to prove the absence of arsenic 
in the reagents add slowly from the funnel tube the solu- 
tion of the material in 20% sulphuric acid or the solu- 
tion obtained by one of the foregoing methods containing 
about 20% of that acid, keeping a steady evolution of gas. 
When the flow slackens add 30% sulphuric acid and later 
40% acid until all arsenic has been expelled, which usually 
requires 2 to 3 hours. If no arsenic mirror forms in the 
constriction of the tube in one hour, further test may be 
abandoned. 

If more than o.i mg. of arsenic appears to be present 
cut off the constriction from the tube and weigh it on an 
assay balance; then dissolve the arsenic in a solution of 
sodium hypochlorite, (antimony being insoluble), wash with 
water and then with alcohol, dry, cool, and weigh. The 
loss is arsenic. 

If the amount of arsenic is very small Sanger com- 
pares the mirror with a series of standard mirrors pre- 
pared in the same apparatus using quantities of a stand- 
ard solution containing from 0.005 to 0.05 mg. of 
AS2O3. To prepare the standard solution i gram of pure AS2O3 is dis- 
solved in arsenic-free sodium hydroxide, acidified with sulphuric 
acid, made up to one liter and 10 cc. of this stock solution further diluted 
to I liter; i cc. = o.oi mg. AS2O3. 

2. Sanger -Black-GiUzeit Method.'^ — The apparatus (Fig. 29), devised 
by Bishop, consists of a 30 cc. salt-mouth bottle provided with three upright 
* Jour. Soc. Chem. Ind., 26, 1907, p. 1115. 



Fig. 29. — Bishop 
Apparatus for 
Arsenic. 



66 FOOD INSPECTION AND ANALYSIS, 

tubes one above the other. The lower tube is 7 cm. long, i cm. in bore, and 
contains strips of filter-paper previously soaked in 5% lead acetate solution 
and dried. The middle tube is of the same size as the lower but shorter. 
It is loosely filled with cotton moistened with 1% lead acetate solution. 
The upper tube has a uniform bore of 2.5 mm. and is bent twice so that 
the upper end is vertical. In this tube is placed a strip of cold-pressed 
drawing paper 2 mm. wide which has been soaked in 5% alcoholic mur- 
curic chloride (or bromide) and dried. 

Place in the evolution bottle 10 grams of stick zinc, a few crystals of 
stannous chloride, a perforated platinum disk and from 2 to 5 grams of 
the material or else the extract of the charred or digested material pre- 
pared as described in the foregoing sections, containing about 20% of 
sulphuric acid. Add enough 20% (1:4) sulphuric acid to nearly fill the 
bottle, attach the three tubes and allow to react for 45 minutes. Com- 
pare the color on the sensitized strip with that of standard strips obtained 
with from 0.005 to 0.05 mg. of AS2O3 in the same apparatus, using measured 
quantities of the standard solution described under the Marsh test. 

Colorometric Analysis. — Certain analytical processes depend on the 
formation of a compound of the substance to be determined having a 
definite color, and the calculation of the quantity present from the inten- 
sity of the color of the solution, compared with that of a solution contain- 
ing a known amount. The comparisons may be made in a special form 
of cylinder or in a colorimeter. The latter has the advantage that a single 
solution of known strength serves within reasonable limits for matching 
any shade in the unknown solution, and for any number of determina- 
tions, the desired depth of the color being secured by varying the length 
of the column. 

Schreiner's Colorimeter.* — This apparatus, shown in Fig. 30, consists 
of two graduated tubes {B), containing the standard and unknown colori- 
metric solutions, the height of the column of liquid in both tubes being 
changed by two immersion tubes {A), which remain stationary while 
the graduated tubes arc raised or lowered in the clamps (C). The mirror 
D reflects the light through the tubes, and the mirror E reflects it again 
to the eye of the operator at F. 

In making the comparisons, the tube containing the solution of either 
known or unknown strength is set at a definite point, and the other tube 
is raised or lowered until the colors match. If R is the reading of the 
standard solution of the strength 5, and r the reading of the colorometric 

solution of unknown strength s, then s = —S. 

r 

* Tour. Am. Chem. Soc. 27, 1905, p. 1192. 



GENERAL ANALYTICAL METHODS. 



67 



If desired, standard slides of colored glass, such as accompany the 
Lovibond tintometer, may be used at G for matching the solution of un- 
known strength, the value of these slides being 
determined by comparison with a standard 
solution. 

The Lovibond Tintometer may be used 
for colorometric chemical analysis, but is not 
so well suited for this purpose as the Schreiner 
colorimeter, it is especially designed for deter- 
mining the color value of liquid and solid 
technical products, such as beer, wine, oil, 
flour, paper, etc. 

The instrument itself is of simple construc- 
tion, consisting of an elongated box with an 
eyepiece at one end and two rectangular 
openings at the other, one for the solution or 
substance to be examined, the other for the 
standard glass slides used for matching the 
color. Light is reflected through the openings 
by means of a square piece of opal glass 
mounted on a jointed standard. Liquids are 
examined in rectangular cells with glass sides 
by transmitted hght, while powders are pressed 
into a form and examined by reflected light. 

The standard slides used in general work 
are red, yellow, and blue in even graduation 
from .006 to 20 tint units which can be combined so as to produce any 
desired tint or shade of any color. The results are expressed in terms 
of standard dominant colors (red, yellow, and blue), subordinate colors 
(orange, green, and violet) obtained by combining equal values of two 
dominant colors, and neutral tint (black) obtained by combining equal 
values of the three dominant colors. Thus 

o.6i? + 5.6F = o.60+5.oF 
o.oSi? + 1.5 F+o.2j5=o.o8iV+o. 12^ + 1.37 
i.2R + i.oB = i.oV +0.2R 
in which i? = red, F = yellow, -S = blue, 0= orange, G = green, F = violet, 
AT" = neutral tint or black. 

Special slides may be obtained for the examination of any desired 
product. For example, slides of brown shades are furnished for beer, 
of yellow shades for oils, and so on. 




Fig. 30. — Schreiner's Colori- 
meter with a Tube showing 
Graduation. 



1 



CHAPTER V. 
THE MICROSCOPE IN FOOD ANALYSIS. 

Microscopical vs. Chemical Analysis. — A very important means of 
identification of adulterants in many classes of food products is furnished 
by the microscope, which in many cases affords more actual information 
as to the purity of food than can be obtained by a chemical analysis. 
This is especially true of coffee, cocoa, and the spices, wherein the micro- 
scope serves to reveal not only the nature of the adulterants, but also not 
infrequently the approximate amount of foreign matter present. In the 
case of the cereal and leguminous products so commonly employed as 
adulterants, a microscopical examination is of paramount importance. 

The chemical constants of many of the adulterants of coffee and the 
spices do not always differ sufficiently from those of the pure foods in 
which they appear to be distinguished therefrom with accuracy and 
confidence by a chemical analysis alone. On the other hand, one who 
is familiar with the appearance under the microscope of the pure foods 
and of the starches and various ground substances used as adulterants, 
can, with certainty, identify very minute quantities of these materials, 
when present, with the same ease that one can recognize megascopically 
the most famihar objects about him, 

A chemical test may, for example, indicate the presence of starch, 
but it cannot reveal the particular kind of starch. The microscope will 
at once show whether the starch present is wheat or corn or potato or 
arrowroot, since these starches differ almost as much in microscopical 
appearance as do the physical characteristics of the grains or tubers from 
which they are obtained. Again, by a chemical analysis an abnormal 
amount of crude fiber may show the presence of a woody adulterant, 
but only the microscope will enable one to decide whether the impurity 
consists of sawdust, chaff, or ground nut shells. Not only in such in- 
stances as these is the microscopical examination of greater importance 
than a chemical analysis, but it is a much quicker guide. 

The Technique of Food Microscopy. — The recognition of adulterants 
by the microscope requires some experience but no more than may be 
acquired by a chemist who will give the subject serious attention. In 

68 



THE MICROSCOPE IN FOOD ANALYSIS. 69 

the examination of flour, commercial starch, cocoa, coffee, tea, and the 
spices for adulteration, a careful study of the powdered substance in tem- 
porary water mounting will in most cases prove sufficient to familiarize 
the food analyst with their characteristics under the microscope. In 
extended studies standard works on the microscopy of foods should be 
consulted. 

It is not necessary for him to familiarize himself with the details of 
section cutting, dissecting, or permanent mounting unless he so desires. 
Such details are given by Behrens,* Chamberlain, f Gage, J and Zimmer- 
man. § 

Microchemical methods of ana'ysis, a subject quite distinct from 
food histology, is fully treated by Chamot.lj 

Standards of Comparison. — For standards the analyst should provide 
himself with as complete a set as possible of the various materials to be 
examined, taking care that their absolute purity is established. Where- 
ever possible, he should grind the sample himself from carefully selected 
whole goods. These, together with samples of the starches and other 
adulterants, all of known purity, should be contained in small vials care- 
fully stoppered and plainly labeled, arranged alphabetically or in some 
equally convenient manner in the desk or table on which the microscope 
is commonly used. The adulterants included in this set of standards 
should be not only those which experience has shown most liable to be 
employed, but any which, by reason of their character, might in the 
analyst's opinion be used under certain conditions. 

APPARATUS. 
The Microscope-stand. — An expensive or complicated stand is un- 
necessary. The prime requisites for good work in a microscope-stand are 
firmness or rigidity, and accuracy in centering. An inexpensive stand 
possessing these features can be used for the best work, providing the optical 
parts are satisfactory. It is well, if economy must be practiced, to purchase 
a simple stand provided with the society screw, and let the larger portion 
of the allowance go for a high grade of lenses, since many of the attach- 
ments inherent in a high-priced stand, though often of convenience, may 
well be dispensed with. 

* Guide to the Microscope in Botany. 

t Methods in Plant Histology. 

X The Microscope and Microscopical Methods. 

§ Botanical Microtechnique. 

II Elementary Chemical Microscopy, New York, 1915. 



70 



FOOD INSPECTION AND ANALYSIS. 



A stand of the so-called continental type (having the horseshoe base) 
Is preferable. A square stage is rather more convenient than the circular 
form, and the jointed pillar possesses advantages over the rigid variety 
in ease of manipulation that are certainly worth considering. 

The smooth working of both the coarse and fine adjustments should 
not be lost sight of. If the microscope is to be used exclusively for food 
work, a substage condenser is unnecessary, hence the construction of the 




Fig. 31. — Continental Type of Microscope. 

substage may be very simple, unless bacteriological work is to be done 

as well. 

A nose-piece, while not indispensable, is a great convenience for the 
quick transfer of objectives. A double nose-piece carrying two objectives 
is ample for routine food work. 

The Optical Parts are by far the most important, and should be of 
superior quality, though not necessarily of the most expensive makers. 
The food analyst should have at least two objectives, one for high- and 
one for low power work, and preferably two oculars. 

For the routine examination of powdered food substances the writer 
prefers a ^-inch objective, used with a medium ocular, the combination 
giving a magnificatiDn of from 240 to 330 diameters, according to the 
jcular employed. For a low-power objective the |-inch is a conven- 



THE MICROSCOPE IN FOOD ANALYSIS. 



71 



lent size. It is useful as a finder preliminary to examination with the 
higher power, and, in connection with a low-power eyepiece, is well adapted 
for the examination of butter and lard, anc^for use with the polariscope. 

An eyepiece micrometer mounted in an one inch ocular is indispen- 
sable for measuring starch grains and other elements. It is calibrated 
by means of a stage micrometer. 

The Micro-polariscope. — This accessory is useful in the identification 
of starches and other ingredients, and for ascertaining whether or not 
fats have been crystallized. The polarizer is held below the stage, while 
the analyzer is applied above the objective, either in the tube or above 
the ocular. 





Fig. 32. — Polarizer and Analyzer for the Microscope. 

A common form of construction is one in which the substage is adapted 
to carry interchangeably the diaphragm tube and the polarizer. If the 
polariscope is much used, it becomes desirable to provide means for 
quickly changing the polarizer and diaphragm tube below the stage, and 
for moving the analyzer in and out of place above the objective. 
Winton* has devised a microscope-stand with this in view, especially 
adapted to the needs of the food analyst. 

If the polariscope is to be used often, it is convenient to have within 
easy access two stands, one with the polariscope mounted in place in 
v-^onnection with low-power glasses ready for use, and the other stand 
)rovided with the ordinary high- and low-power objectives only. 

Microscope Accessories include of necessity a large number of slides 
ind cover glasses. The latter should be No. 2 thickness, | inch, either 
round or square. 

One or more dissecting-needles in holders and a sniall hand magni- 
fying-glass should also be provided. 



* Journal App. Microscopy, 2, p. 550. 



72 



FOOD INSPECTION AND ANALYSIS. 



Other useful accessories are. a mechanical stage, a pair of fine tweezers, 
knives, scissors, and, if sections are to be cut, a plano-concave razor. 

MICROTECHNIQUE. 

Preparation of Vegetable Food Products for Microscopical Examina- 
tion. — The ground spices and cocoas of commerce are usually of the 
requisite fineness for direct examination without further treatment. Coffee, 
chocolate, starches, and similar products should be ground in a mortar 
fine enough to pass througii a sieve with from 60 to 80 meshes to the inch. 

A small portion of the powdered sample is taken up on the tip of a 
clean, dry knife-blade, and placed on the microscope-slide. By means 
of a medicine-dropper a drop of distilled water is applied, and the wetted 




Fig. 33. — Mechanical Stage for Microscope. 

powder is then rubbed out under the cover-glass between the thumb and 
finger to the proper fineness. 

The water-mounted slide thus prepared, while useful only for tem- 
porary purposes, has proved to be best adapted to the analyst's require- 
ments for routine microscopical examination of powdered food products 
for adulteration, partly because water is the best medium in most cases 
for showing up the structural characteristics of these substances and their 
adulterants, and partly because it serves best for the "rubbing out" 
process between thumb and finger under the cover-glass, whereby the 
sample is brought to the requisite degree of fineness. 

Experience will soon show how far this rubbing out should be carried 
for the best effects. Gentle pressure should be applied, care being taken 
not to break the cover-glass, especially if the sample contain anything of 
a grittv nature. The rubbing should be continued till the coarser par- 



THE MICROSCOPE IN FOOD ANALYSIS. 73 

tides and overlying masses are separated and distributed uniformly, but 
if too long persisted in, the forms of the tissues, starch grains, and other 
characteristic portions will be partially destroyed and of too fragmentary 
a nature to be readily recognizable. 

Canada Balsam in Xylol is a useful mountant for the examination of 
starches with polarized light. In this medium, under ordinary illumina- 
tion, the starches are not plainly visible, since the refractive index of the 
two are nearly identical, but with crossed nicols the starch grains stand 
out clearly and distinctly in a dark background. If the material is not 
perfectly dry it should be soaked in absolute alcohol and then in chloroform 
or xylol until dehydrated. 

Glycerin. — A mixture of equal parts of glycerin and water is 
perhaps the best medium for permanent mounts, but considerable skill is 
required to finish the preparation with cement on the edge of the cover- 
glass. 

Glycerin jelly is more readily handled by the beginner since no cement 
is required. 

Glycerin Jelly * is prepared as follows : i part by weight of the finest 
French gelatin is soaked two hours in 6 parts of distilled water, after which 
7 parts by weight of C. P. glycerin are added, and to each lOo parts of 
the mixture add i part of concentrated carbolic acid. Heat the mixture 
while stirring till flocculency disappears and filter through asbestos while 
warm, the asbestos being previously washed and put into the funnel 
while wet. The jelly is solid at ordinary temperatures, and must be 
warmed to melt. A small bit of this jelly is removed from the mass by 
a knife-blade and placed on the clean-slide, which is held over a gas flame 
till the jelly is melted. The powdered specimen being then shaken into 
the molten drop, the cover-glass is gently placed upon it (being brought 
down obliquely to avoid formation of air-bubbles) and pressed down in 
place. 

Microscopical Diagnosis. — It is never safe to pass judgment on a 
spice or other food by the microscopical examination of a single portion. 
Several slides should be prepared with bits of the powder taken from 
different parts of the mass, before the character and extent of the adultera- 
tion can be safely determined. Care should be taken that the shde, the 
knife-blade, the water, and the medicine-dropper be perfectly clean and 
free from contamination with previous specimens. 

It should be borne in mind that at best a composite powdered sample 

* Botan. Centralbl., Bd. i, p. 25. 



1 



74 FOOD INSPECTION AND ANALYSIS. 

is but a mechanical mixture of various tissues, and that no two portions 
will show exactly the same composition. 

Characteristic Features of Vegetable Foods under the Microscope.— 

The structural features of a powdered spice, examined microscopically, 
will be found to differ considerably in appearance from those of a thin, 
carefully mounted section of the same spice. Instead of the beautiful 
arrangement of cells and cell contents with the perfect order of various 
parts as seen in the mounted section, one finds in the powdered sample 
under the microscope what often appears to be a most confusing mass 
of fragments of various tissues. For this reason the most striking charac- 
teristics seem to vary with different observers, and it is a well-known 
fact that microscopists differ widely as to conceptions of size, shape, and 
ordinary appearance, even in the case of certain of the well-known starch 
grains. It is on this account that, irrespective of the description of others, 
the analyst should familiarize himself with the microscopical appearance 
of the foods with which he is dealing, as well as of their adulterants, form- 
ing his own standards as to what constitute the recognizable features, 
from specimens prepared by himself. 

In the large variety of ground berries, buds, tubers, barks, etc., from 
which the spices and condiments are prepared, as well as in the grains, 
legumes, shells, fruit stones, and other materials forming the most familial 
adulterants, the kinds of plant tissues and cell contents which, under 
the microscope, serve as distinguishing marks or guides for identification 
are comparatively few in number. 

The most common of these varieties of cell tissue and of cell contents 
to be met with by the food microscopist in his work are briefly the follow- 
ing: 

Parenchyma. — This is most abundant and widely distributed, forming 
as it does the thin-walled, cellular tissue of nearly all vegetable food sub- 
stances. The walls of parenchyma cells are, as a rule, colorless and 
transparent. The forms of the cells are varied and are often sufficiently 
characteristic in themselves to identify the substance under examination. 

Sclerenchyma, or stone cells, are the thick-walled woody cells forming 
the hard part of nut shells, fruit stones, and seed coverings, occurring also 
in some fruits and barks. These cells are more often colored and of 
various shapes but almost always irregular, sometimes elongated, as in 
cocoanut shells and olive stones, occasionally nearly rectangular, as in 
pepper shells, and sometimes polygonal or nearly circular. 

In appearance the sclerenchyma cell commonly has a more or less 



THE MICROSCOPE IN FOOD ANALYSIS. 



75 



deep, central or axial cavity, from which small fissures extend through 
the thick walls. See Fig. 35. 

Variously shaped sclerenchyma cells are found in allspice, cassia, 

9.^ ? 




Fig. 34.— Typical Forms of Various Cell Tissues. Longitudinal section through a clove, 
showing: Fp, two forms of parenchyma; J5, bast fibers; g, vascular and sieve 
tissue; KK', cells with calcium oxalate crystals. (After Vogl.) 

pepper, clove stems, nut shells, etc. Stone cells are optically active to 
polarized light, and between crossed nicols are very conspicuous by their 
bright appearance. 



St — 




Fig. 35. — Sclerenchyma, or Stone-cell Tissue. A cross-section through the stone-cell 
layer of the fruit shell of black pepper. (After Vogl.) 

Fibro-vascular Bundles are composed of three parts: the bast fibers, 
or mechanical elements, the phloem, and the xylem. 



76 



FOOD INSPECTION AND ANALYSIS. 



Bast Fibers are elongated, pointed sclerenchyma cells, of which flax 
fibers are examples. 

Sieve Tubes, the characteristic elements of the phloem, are thin- 
walled tubes with perforated partitions known as sieve plates. 

Vessels or Ducts occur in the xylem. They are designated as 
spiral, annular, reticulated, or pitted, according to the nature of the 
walls. 

Corky Tissue, or Suberin, constitutes the thin-walled, spongy cells 
forming the protective, outer dead layers of the bark. This is found 
in cassia, and in the barks used as adulterants. Suberin is tested for by 
potassium hydroxide (p. 80). jf^ 

Starch wherever it occurs furnishes the most charac- 
teristic feature of the cell contents, and, as a rule, will at 
once indicate under the microscope, by the shape and 
grouping of its granules, the particular substance of which 
it forms a part. It is very abundantly distributed through- 
out the vegetable kingdom and occurs in a wide variety of 
forms. It is particularly conspicuous when viewed by 
polarized light. Between crossed nicols such starches 
as corn, potato, and arrowroot show out brightly from 

a dark background with dark crosses, the bars of which ^^°' •^^• 

, , ., . , , ,,„ , . ted Ducts of Chic- 

intersect at the hilum of each granule. When a selemte ory. (After Vogl.) 

plate is introduced above the polarizer, a beautiful play of colors is 

seen with various starches, a phenomenon which Blyth apphes as a 

means of identification and classification, but which more modern micro- 

scopists regard as of minor importance to distinguishing the various 

starches morphologically. Starch is found naturally in the cereals, legumes, 

and many vegetables, in cassia, allspice, nutmeg, pepper, ginger, cocoa, 

and turmeric. The cereal and leguminous starches from their inertness 

and cheapness constitute the most common adulterants of the spices and 

of powdered foods in general. Starch grains are found in the cells of the 

parenchyma and in other cellular tissues. Iodine is the special reagent 

(p. 78). 

Gums and Resins occur in characteristic forms among the cell contents 

of some of the spices. As an example, the portwine-colored lumps of gum 

in allspice furnish one of the most ready means of recognizing that spice 

microscopically. Resin is tested for microchemically with alkanna tincture 

(P- 79)- 




-Reticula- 



THE MICROSCOPE IN FOOD ANALYSIS. 77 

Aleurone or Protein Grains are found in many seeds, but are not 
especially characteristic. They somewhat resemble small starch grains. 
Most varieties of protein grains are soluble in water, but some are insoluble. 
The soluble varieties, which are not apparent in water- mounted specimens, 
must be examined in absolute alcohol, glycerin, or oil. In leguminous 
seeds aleurone occurs closely intermingled with starch in the same cells, 
while in the cereals it occupies the whole cell. 

Protein grains are tested for under the microscope by iodine in potas- 
sium iodide, which turns them brown or yellowish brown, and by Millon's 
reagent, which colors them brick red. 

Plant Crystals are not uncommon in the class of substances which 
the food analyst examines. Among the common forms are the piperin 
crystals found in pepper. Calcium oxalate occurs in many vegetable 
products as prismatic crystals, crystal aggregates, or needle-shaped 
crystals (raphides). 

Crystals of calcium carbonate are sometimes met with also, as, for 
example, in hops. Calcium oxalate crystals are insoluble in acetic acid, 
while being readily soluble in dilute hydrochloric. Calcium carbonate 
crystals are soluble with effervescence in both acids. The acid reagents 
are directly applied to the sample in water-mount under the cover-glass, 
and the reaction observed through the microscope. 

Fat Globules are of common occurrence in many foods and appear of 
various sizes, sometimes large and conspicuous, and again almost lost 
sight of because of their minuteness. They are sometimes colorless, as in 
mace, and sometimes deeply tinted, as in cayenne. Alkanna tincture is 
used as a reagent for fat (p. 79). 

Other Cell Contents of less importance, but which may be identified by 
the microscope with reagents, are tannic acid (tested for by chloriodide 
ot zinc and ferric acetate (pp. 78 and 79), and various essential oils, for 
the detection of which alkanna tincture is employed. 

REAGENTS IN FOOD MICROSCOPY. 

Unless a more extended microscopical investigation of vegetable food 
substances is contemplated than is involved in the mere identification of 
adulterants, the analyst will have little need for reagents other than iodine 
in potassium iodide, chloral hydrate solution, and potassium hydroxide 
solution, the last two for clearing, but will depend almost entirely on the 
form and appearance of the various tissues or tissue fragments, as well 
as on the abundance, shape, and distribution of such distinctive cell con- 
tents as the starches, fat globules, or crystals. 



78 FOOD INSPECTION AND ANALYSIS. 

Analytical reagents are applied to the water-mounted sample by means 
of a glass rod or pipette, with which a drop of the reagent is deposited 
on the sample upon the slide, having previously lemoved the cover, 
which is afterwards replaced. Or, without removing the cover-glass, a 
drop of the reagent is placed in contact with one side of it on the slide. 
Along the opposite side of the cover is then placed a piece of filter-paper. 
The latter withdraws by capillary attraction a portion of the water from 
under the cover-glass, and this is replaced by the reagent, which thus 
intermingles with the particles of the substance. 

The following reagents include those needed in routine work as well 
as some others suited for studies of the general nature of tissues and cell 
contents. 

A. Analytical Reagents. — Iodine in Potassium Iodide. — Two grams. 
of crystallized potassium iodide are first dissolved in loo cc. of distilled 
water and the solution is saturated with iodine. 

This reagent is indispensable for the identification of starch, especially 
when the latter is present in minute quantities. Starch granules when 
moistened with water are turned blue by iodine, the reaction being exceed- 
ingly delicate under the microscope, even when the starch granules are 
very minute and insignificant without the reagent. 

Iodine in connection with sulphuric acid is also useful in distinguishing 
pure cellulose from its various modifications, such as lignin and suberin. 
For this purpose the water-mounted sample is first permeated with the 
iodine reagent, after which concentrated sulphuric acid is applied, with 
the result that all pure cellulose is turned a deep-blue color, while the 
modified forms of cellulose are colored yellow or brown. The cellulose 
is first converted by the sulphuric acid into a carbohydrate isomeric with 
starch, known as amyloid. 

Protein grains are colored brown or yellow brown by the action of 
iodine. 

Chloriodide 0} Zinc. — Pure zinc is dissolved in concentrated hydro- 
chloric acid to saturation, and an excess of zinc added. The solution is 
then evaporated to about the consistency of concentrated sulphuric acid, 
after which it is first saturated with potasshim iodide, and finally with 
iodine. 

This reagent may be used instead of sulphuric acid and iodine for the 
detection of cellulose, since the zinc chloride converts the cellulose into 
amyloid, which the reagent colors blue. 

Chloriodide of zinc is useful for detecting tannic acid in cell contents. 
For this purpose the above reagent is much diluted by the addition of 



THE MICROSCOPE IN FOOD ANALYSIS. 79 

a 20% solution of potass'mm iodide. In this diluted form, when applied 
to the sample, a reddish or violet coloration is imparted to cell contents 
having tannin. 

Phenol-hydrochloric Acid is prepared by saturating concentrated 
hydrochloric acid with the purest crystallized carbolic acid. Wood fiber, 
or lignin, when treated with a drop of this reagent under the cover-glass, 
and exposed for half a minute to the direct sunlight, will be colored an 
intense green, which quickly fades. 

Indol. — Several crystals of indol are freshly dissolved in warm water. 
Lignified cell walls assume a deep-red color, when the specimen to be 
examined is treated first with a drop of the indol reagent, and afterwards 
washed with dilute sulphuric acid, i : 4. 

Millon's Reagent. — This is prepared by dissolving metallic mercury 
in its weight of concentrated nitric acid, and diluting with an equal volume 
of water. This reagent, which should be freshly prepared, is of use in 
testing for protein compounds, which turn brick red when treated with it, 
especially on gently warming the slide. 

Tincture 0} Alkanna. — A 70 or 80% alcoholic extract of alkanna root, 
when kept in contact with resins, fixed oils, fats, or essential oils for a 
short time, stains these cell contents a lively red. The staining is hastened 
by the aid of heat. Essential oils and resins are soluble in strong alcohol, 
while iixed oils and fats are insoluble, hence the distinction between these 
classes of cell contents may be made by the application of alcohol to the 
alkanna-stained specimen. 

Ferric Chloride, Ferric Acetate, or Ferric Sulphate, used in dilute aqueous 
solution, are all applicable as reagents for tannic acid, which, when present 
in appreciable amount, will be colored green or blue by either of these 
reagents. 

B. Clarifying Reagents. — ]\Iany of the harder cellular tissues are too 
opaque for careful examination, and may be rendered transparent by clarify- 
ing or bleaching. The simplest and for many purposes the most satis- 
factory method for clearing the tissues is by boiling a water mount, replacing 
the water lost by evaporation. Proceeding in this manner, there is ordi- 
narily no danger of the slide or cover-glass breaking; if the boiling is 
carried out without a cover-glass, the slide is alm.ost sure to break. A 
portion of the powdered sample is cither boiled with a drop. of the reagent 
under the cover-glass or is allowed to soak for hours or even days in the 
reagent, using a drop of the same reagent as a medium for examination 
on the object-glass, instead of water. The clarifying reagents mxost com- 
monly used are the following: 



80 FOOD INSPECTION AND ANALYSIS. 

Chloral Hydrate. — A 60% solution. 

Ammonia. — Concentrated, or 28% ammonia is commonly used. 

Potassium Hydroxide, used in various degrees of concentration, often 
in dilute solution, say 5%. This reagent, added to a water mount, 
causes swelling of the cell wall, and dissolves intercellular substances 
and protein. It bleaches most of the coloring matters, destroys the 
starch, and forms soluble soaps with the fats. Potassium hydroxide is 
also used in testing for subcrin, which is extracted from corky tissue 
on boiling with the reagent, and appears as yellow drops. 

Schnitzels Macerating Reag'^nt (concentrated nitric acid and chlorate of 
potassium) is best used by placing the powder or bit of tissue to be treated 
in a test-tube with an equal volume of potassium chlorate crystals, adding 
about 2 cc. of concentrated nitric acid, and warming the tube till bubbles 
are evolved freely, or until the necessary separation of cells is effected. 
The sample is then removed and washed with water. 

By this treatment, bast and wood fibers as well as stone cells are 
readily separated from other tissues. 

Cuprammonia (Schweitzer's Reagent). — This is prepared by adding 
slowly a solution of copper sulphate to an aqueous solution of sodium 
hydroxide, forming a precipitate of cupric hydroxide, which is separated 
by filtration, washed, and dissolved in concentrated ammonia. It should 
be freshly prepared, and is never fit for use unless it is capable of immediately 
dissolving cotton. Indeed its chief use is as a test for cellulose, which it 
readily dissolves. In observing this reaction under the microscope, the 
powdered specimen under the cover-glass should be only slightly damp 
before a drop of the fresh reagent is applied. The cell walls are seen to 
swell up and gradually become more and more indistinct, till they finally 
disappear. 

Cuprammonia is also used as a test for pectose, which occurs in many 
cell walls, often intermixed with cellulose. When treated with this reagent, 
cellular tissue containing pectose is acted upon in such a manner that 
a delicate framework of cupric pectate is sometimes left behind, after the 
dissolution of the cellulose with which it is mingled.* 

PHOTOMICROGRAPHY. 

The photomicrograph serves as a simple means of keeping perma- 
nent records of unusual forms of adulteration encountered in the course 
of routine examination. Besides this, the photomicrograph has at 
times proved its usefulness as a means of evidence in court, showing as it 
does with faithfulness the pres ence of a contested adulterant. It is true 

* Poulsen, Botanical Micro-chemistry, p. 15. 



THE MICROSCOPE IN FOOD ANALYSIS. 



81 



that from an artistic and didactic standpoint the photomicrograph of a 
powdered sample is often disappointing, due to the fact that ordinarily 
much of the field is out of focus, unless a very simple homogeneous sub- 
ject is photographed, as, for instance, starch. As compared with the care- 
fully prepared drawing of a section, which shows minute details of struc- 
ture, the photomicrograph portrays what happens to be in focus. 

SUMMARY OF MICROCHEMICAL REACTIONS FOR IDENTIFYING 
CELLULAR TISSUE AND CELL CONTENTS. BASED ON BEHRENS'.* 





Iodine in 

Potassium 

Iodide. 


Chlor- 

iodide of 

Zinc. 


Iodine 
and Sul- 
phuric 
Acid. 


Cupram- 
monia. 


Potassium 
Hydroxide. 


Concen- 
trated 
Sulphuric 
Acid. 


Schultze' s 
Mixture. 


Cellulose, cell substance. 
Lignin, wood substance. 
Middle lamella, inter- 


Yellow to 

brownish 

Yellow 

Yellow 

Yellow or 
brownish 

Blue 
Brown 
yellow 


Violet 
Yellow 

Yellow 

Yellow or 
brown 


Blue 

Yellow to 
brownish 

Yellow 

Brown 


Dissolves 
Insoluble 

Insoluble 
Insoluble 


Swells up 
Dissolves 


Dissolves 
Dissolves 


Dissolves 

Dissolves 
easily 


Suberin, cork substance. 
Starch 


Insoluble 

in cold. 

By boiling 

it comes out 

in drops 

Dissolves 

Dissolves 


Insoluble 


easily 
Gives 
eerie 
acid reac- 
tiont 


























Fat 










Saponifies 
























Reddish 
to violet 





























































Phenol- 
hydro- 
chloric 
Acid. 


Indol. 


Ferric 

Acetate 
or Sul- 
phate. 


Alkanna 
Tincture. 


Hydro- 
chloric 
Acid. 


Acetic 
Acid. 


Millon's 
Reagent. 


Cellulose, cell substance. 
Lignin, wood substance. 

Middle lamella, inter- 


Uncolored 
Green 

Green 
Uncolored 


Uncolored 

Cherry 

red 

Cherry 

red 

Uncolored 






































































Brick red 










Bright red 
Bright red 
Bright red 








Fat 


































Blue or 
green 








Calcium oxalate crystals 
Calcium carbonate ' ' 








Soluble 
without ef- 
fervescence 

Soluble 
with effer- 
vescence 


Insoluble 

Soluble 
with effer- 
vescence 





























* Microscopical Investigation of Vegetable Substances, page 356. 

t When treated with the reagent, suberin forms masses of eerie acid, soluble in ether, alcohol, or 
chloroform. 

While the analyst examines microscopically the ordinary powdered 
spice, for example, he constantly moves with his hand the fine adjustment- 
screw, bringing into focus different parts of the field successively. This 



82 FOOD INSPECTION AND ANALYSIS. 

he does unconsciously, so that he does not realize how far from flat the 
field actually is till he undertakes to photograph it, when, as a rule, only 
a small portion is in good focus. It is therefore impossible in one photo- 
graph to show successfully many varied forms of tissue or cell contents 
in the powder, but separate photographs should be made as far as possible 
with only a little in each. Thus, for example, with a composite subject 
like powdered cassia bark, it would be very difficult to show starch, stone 
cells, and bast fibers in one field, all in equally good focus, and, for the best 
results only, one, or at most two, such varied groups of elements should be 
shown in one picture. 

Appurtenances and Methods of Procedure. — The temporary method 
of water-mounting employed by the analyst in routine examination pre- 
sents many difficulties from a photographic point of view. The vibrating 
motion of the particles is very annoying, and some skill is required in using 
just the right amount of water, in avoiding air-bubbles, in waiting the 
requisite amount of time before exposing the plate for the vibratory motion 
to cease, and, on the other hand, avoiding too long delay, which would 
result in the evaporation of the water, and the consequent breaking up of 
the field. In the writer's experience, however, in spite of these difficulties, 
the water-mounting gives decidedly the clearest results, and, with patience 
on the part of the operator, it is in many ways the most desirable method of 
mounting for photographic purposes. It is in fact the method employed in 
making most of the photomicrographs of powdered specimens that appear 
in the plates at the end of this volume, though a few were mounted in 
glycerin jelly, and the starches for the polarized-light pictures in Canada 
balsam. The sections of tissues shown in the plates were mounted some 
in glycerin and others in glycerin jelly. 

Experience has shown that two degrees of magnification well cal- 
culated to bring out the chief characteristics of the spices and their adul- 
terants in a photomicrograph are 125 and 250 diameters. The starches, 
which are the most common of any one class of adulterants, vary very 
widely in the size of their granules. With these the larger magnification 
of 250 has been found satisfactory, while the general appearance of the 
composite ground-spice itself under the microscope, as well as that of 
such adulterants as ground bark, sawdust, chicory, pea hulls, and the 
like, is best shown with the lower power of 125.* 

* The degrees of magnification adopted in the originals of most of the photomicrographs 
illustrated in the accompanying plates are accordingly 125 and 250, but in the process of 
lithographing, the photographs were slightly reduced, so that the actual scales in the repro 
duction are 110 and 220 respectively. 



THE MICROSCOPE IN FOOD ANALYSIS. 



83 



1 he object, mounted in the manner above described, is best examined 
when held in a mechanical stage, furnished with micrometer adjust- 
ments, in such a manner that a typical field may be selected and held 
in place long enough to photograph. 

The Camera. — This need not of necessity be complicated, but may 
consist simply of a horizontal wooden base on which the microscope 




Fig 37a. — A Convenient Photomicrographic Camera, 
rests, and an upright board firmly secured to the base, carrying a frame 
for an interchangeable ground glass and plate-holder, with a rubber 
gauze skirt hanging from the frame, adapted to be gathered and tied 
about the top of the microscope-tube. Means are further provided, as 
by a slotted guide and screw, for adjusting the frame at any desired height 
on the upright board.* 

A more convenient form of apparatus now employed by the writer is 
that shown in Figs. 37a and 376. 

* Such a contrivance as this was employed in making some of the accompanying photo- 
micrographs. 



84 



FOOD INSPECTION AND ANALYSIS. 



The base is a solid iron plate upon which the microscope rests (any 
microscope may be used with this camera), and above which the camera 
bellows is supported on two solid steel rods. The bellows is supported 
at either end on wooden frames. 

The ground glass is provided with a central transparent area, formed 
by cementing a cover-glass upon the ground glass, and permits the accurate 
focusing of the most delicate detail by means of a hand magnifying-glass. 
The vertical rods supporting the bellows are attached to metal arms, 
immovably fixed to a horizontal axis, thus permitting the camera to be tilted 




Fig z^b. — Photomicrographic Camera in Horizontal Position 

to any angle from vertical to horizontal. It is fixed at the desired angle by 
means of heavy hand-clamps. 

In use the camera is placed in a vertical position and the microscope 
adjusted on the base so that its tube will coincide with the opening in 
the front of the camera. The connection between microscope and camera 
is made light-tight by means of a double chamber, which permits consider- 
able vertical motion of the tube of the microscope without readjustment. 
A jointed telescoping rod is attached to the upper end of the camera to 
act as a support, giving perfect steadiness when in a horizontal position, 
and folding down parallel with the bellows so as to be out of the way 
when in any other position. 

Amplification. — The vertical rods are graduated in inches for deter- 
mining the amount of amplification, and to show when the ground glass 
is at right angles to the optical axis. The following simple rule for deter- 
mining the amount of amplification will give sufficiently accurate results. 
When photographing without the eyepiece, divide the distance of the 
ground glass from the stage of the microscope in inches, by the focal length 
in inches of the objective used. When photographing with the eye- 
piece, proceed as above and multiply the result by the quotient obtained 
by dividing lo by the focus in inches of the eyepiece used. 



THE MICROSCOPE IN FOOD ANALYSIS. 85 

Adjustment and Manipulation. — The microscope can be placed in 
any position desired, and the camera adjusted to it. The bellows can then 
be raised and the microscope used as though no camera were present. 
When an object is to be photographed, the bellows may be slid into posi- 
tion without in any way disturbing the arrangement of light or object, 
the final focusing on the ground glass being effected quickly by means of 
the fine adjustment-screw of the microscope. The exposure having 
been made, observation through the microscope may be continued with- 
out interruption by simply raising the bellows again. 

When a water-mounted specimen is to be photographed, the camera 
and microscope tube should be vertical instead of inclined as shown in 
the cut. 

The camera is best kept in a dark room where the exposures are to 
be made, the source of light being a i6- or 32-candle-power electric lamp, 
preferably provided with a ground-glass bulb. The light from this lamp 
is first carefully centered by moving the reflector of the microscope. 

In making pictures, for instance, of the magnification of 250 diameters, 
the objective, having an equivalent focus of ^ inch, may be used in 
combination with the one-inch ocular, with the ordinary tube length of 
microscope. For a lower power, such as 125 diameters, the same objec- 
tive is employed, but the eyepiece is left out, it being found necessary 
in this case to remove the upper tube of the microscope, which ordinarily 
carries the eyepiece, as otherwise the size of the field to be photographed 
would be restricted. In each case a diaphragm is used in the microscope 
stage, having an opening of about the same size as that of the front lens 
of the objective. By means of a stage micrometer scale, the proper posi- 
tion of the camera back is previously determined to give the required 
magnification. 



CHAPTER VI. 

THE REFRACTOMETER. 

The refractive index ranks in importance with the specific gravity 
as a means of determining the identity and purity of various food 
products, as well as of estimating the percentage of valuable constituents. 
Various forms of refractometer are used in food analysis. 

The Abbe refractometer is of general application in determining 
the refractive index of fats, fatty oils, waxes, and essential oils, in esti- 
mating the solids in saccharine substances, and in other analytical opera- 
tions. It employs but a few drops of the material, and reads the refractive 
index directly, using ordinary white light. 

The immersion refractometer, an instrument of recent introduction, 
is suited for the examination of milk serum to detect added water 
therein, the detection and determination of methyl alcohol in ethyl 
alcohol, and the standardization of a wide variety of solutions. The 
instrument is immersed directly in the liquid to be examined, the degree 
of refraction being indicated on an arbitrary scale. 

The Pulfrich is used with the sodium light, and requires a larger 
amount of material than the Abbe, the liquid being held in a cylinder 
above the prism. The scale reading is in angular degrees, from which 
the index of refraction is calculated by a formula or from a table. The 
instrument is provided with a temperature-controlling apparatus. 

In the Amagat and Jean or oleo-refractometer, an outer and an inner 
cylinder are respectively filled with an oil of known value or purity, and 
with the oil to be examined. By the comparative displacement to the 
right or left of a beam of white light passing through both cylinders, the 
displacement being read in degrees on an arbitrary scale, the refraction 
of an oil may be measured. Two oils may thus be readily compared 
under the same conditions, one of known purity, for example, with a 
doubtful sample of the same kind. 

The butyro-refractometer and the Wollny milk fat refractometer (p. 126) 
are, as their names imply, instruments primarily intended for more restricted 
fields of work than the foregoing. They involve the same principle as 
the Abbd, but are simpler in construction and have arbitrary scales. 

Unless such widely varying substances as the waxes and the essential 
oils are to be studied, the Zeiss butyro-refractometer, though primarily 

86 



THE REFRACTOMETER. 87 

intended for the examination of butter and lard, answers most of the 
purposes of the Abbe instrument with the advantage of greater sim- 
phcity, being equally well adapted for examining all the common edible 
oils and fats, as well as other materials. 

THE ZEISS BUTYRO-REFRACTOMETER. 

This instrument (shown in Fig. 38) is so constructed that the degree 
of refraction of a beam of light, which passes obliquely through a thin 




Fig. 38. — The Zeiss Butyro-refractometer. 

film of the fat, is read on an arbitrary scale of sufficient extent to cover 
the widest limits of deviation possible for butter fat and oleomargarine 
under ordinary temperatures. 

The graduation is in divisions from i to 100, covering a variation in 
refractive indices of from 1.4220 to 1.4895. A and B are the two hinged 
hollow portions of the prism casing of the instrument, so arranged that 
when closed together the melted fat is held in a film of sufficient thickness 
between the two opposed transparent prism surfaces, the beam of light, 
either diffused daylight or lamplight, being reflected through it by means 
of the mirror /. The transparent scale is within the telescope tube at 
the height indicated by G. 



88 FOOD INSPECTION AND ANALYSIS. 

The refractometer is connected to any kind of heating arrangement, 
which admits of warm water being transmitted through the prism casing, 
in at D and out at E. A simple arrangement, which suffices for all 
ordinary cases, may expeditiously be improvised in the following manner: 
Fill a vessel of say 2 gallons capacity with water of 40° to 50° C. Into 
this vessel dip the free end of an india-rubber tube slipped over the nozzle 
D and let the vessel be placed at a height of about one-half or one yard 
above the refactometer. Then it will be seen that suction at a tube 
attached to E will cause the warm water to flow through the prism casing 
by the action of the siphon arrangement. By means of a pinch clip the 
velocity of the water may be regulated at will. The waste water 
may be allowed to flow into a second vessel and, provided its tem- 
perature does not fall below 30°, it may be used for replenishing the 
upper vessel. 

When working with solid fats, a temperature must be maintained 
by the heated water well above the melting-point of the fat. With 
liquid oils no heater is necessary, as determinations may be made at 
room temperature, but it is advisable in all cases to have a constant stream 
of water passing through the water jacket, which may be done by directly 
connecting it with the water faucet in the case of oils, since, without such 
precautions to insure even temperature, disturbing variations are liable 
to occur, due to the warming of the prisms by the manipulation of clean- 
ing, etc. 

Refractometer Heater. — ^A regular heater, shown in Fig. 39, is furnished 
by the manufacturers, capable of supplying a current of water of approx- 
imately constant temperature, and will be found of great convenience when 
the instrument is to be used constantly, especially with .the solid fats. 

A supply reservoir A is secured to the wall and is connected by means 
of a rubber inlet tube G to the water faucet C The reservoir is provided 
with a waste overflow pipe and with an outlet tube D, the flow through 
the latter being regulated by the cock H. The tube D leads to the spiral 
heater HS, which is heated by a Bunsen burner. From the heater the 
tube E conducts the warm water through the refractometer, from which 
it flows through the tube F, either directly into the sink, or into the inter- 
mediate vessel B. The temperature of the water is regulated by adjust- 
ing the cock iJ, and the height of the flame of the Bunsen burner. 

Manipulation of the Butyro-refractometer. — The prism casing is first 
opened by giving about half a turn to the right to the pin F, Fig. 38, 
until it meets with a stop. Then simply turn the half B of the prism 



THE REFRACTOMETER. 



89 



casing aside. Pillar H holds B in the position shown in Fig. 38. The 
prism and metallic surfaces must now be cleaned with the greatest care, 
the best means for this purpose being soft linen, moistened with a little 
alcohol or benzine. 

If the sample to be examined is a solid fat, maintain the temperature 
above the melting-point, and apply by a glass rod a drop or two of the 
clear melted fat (filtered if turbid) to the surface of the prism contained 
in the casing B. For this purpose the apparatus should be raised with 




Fig. 39.— The Zeiss Heating Apparatus for all Forms of Refractometer. Shown in the 

cut in connection with the PulMch refractometer. 

the left hand so as to place the prism surface in a horizontal position. 
A liquid oil is directly applied in the same manner without preliminary 
precautions as to heating. Now press B against A, and place F by 
turning it in the opposite direction, in its original position; thereby B 
is prevented from falling back,, and both prism surfaces are kept in close 
contact. Place the instrument again upon its sole plate. 

While looking into the telescope, give the mirror / such a position as 
to render the critical line, which separates the bright left part of the field 
from the dark right part, distinctly visible. It may also be necessary 
to move or turn the instrument about a little. First it will be necessary 
to ascertain whether the space between the prism surfaces be uniformly 
filled with oil or fat, failing which the critical line will not be distinct. 
For this purpose examine the rectangular image of the prism surface 
formed about i cm. above the ocular with a hand magnifier or with the 



90 



FOOD INSPECTION AND ANALYSIS. 



naked eye, placing the latter at its proper distance from the ocular. 
Finally adjust the movable front part of the ocular so that the scale 
becomes clearly visible. 

By allowing a current of wsLter of constant temperature to flow through 
the apparatus some time previous to the taking of the reading, the at first 
somewhat hazy critical line approaches in a short time, generally after a 
minute, a fixed position, and quickly attains its greatest distinctness. 
When this point has been reached, note the appearance of the critical 
fine (i.e., whether colorless or colored, and in the latter case of what color); 
also note the position of the critical line on the centesimal scale, which 
admits of the tenth divisions being conveniently estimated; at the same 
time read the position of the thermometer. 

Testing the Adjustment of the Ocular Scale. — It is imperative that 
the adjustment of the instrument be tested periodically, and in particular 
when it is being used for the first time. This may be done by means 
of the standard fluid supphed with the instrument, the critical line of 
which is approximately colorless, and must occupy the following positions 
in the scale. 



Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


Temper- 


Scale 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


ature. 


Division. 


30= 


68.1 


25° 


71.2 


20° 


74-3 


15° 


77-3 


29° 


68.7 


24° 


71.8 


19° 


74-9 


14° 


77-9 


28° 


69-3 


23° 


72.4 


18° 


75 -S 


13° 


78.6 


27° 


70.0 


22° 


73-0 


17° 


76.1 


12° 


79-2 


26° 


70.6 


21° 


73-6 


16° 


76-7 


11° 


79-8 


25 = 


71.2 


20° 


74-3 


15° 


77-3 


10° 


80.4 



The fractional parts of a degree can accordingly easily be brought 
into calculation (0.1=0.06 scale div.). Deviations of i to 2 decimals 
of the scale divisions are of no consequence, and are in most cases due 
to inexact determinations of temperature. Should, however, careful 
tests result in the discovery of greater deviations, readjustment of the 
scale will be necessary, which may be effected by means of a watch-key 
supplied with the instrument, in accordance with the values given in 
the above table. The watch-key is inserted at G in Fig. 38, and by its 
means the position of the objective, and therefore that of the critical line 
with respect to the scale may be altered. 

Trans] ormation 0} Scale Divisions into Indices of Refraction. — The 
following table, adapted from that of Pulfrich, enables one to convert 
scale readings on the butyro-refractometer into indices of refraction, «^, 
and vice versa: 



THE REFRACTOMETER. 



91 



EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC- 

TOMETER READINGS. 



Refrac- 
tive 








Fourth Deci 


nal of M^_ 








Index. 


j 














1 






"A 





1 


2 


3 


4 


5 


6 


7 


8 


9 










SCALE READINGS 










1.422 


0.0 


0.1 


0.2 


0.4 


0-5 


0.6 


0.7 


0.9 


I.O 


I.I 


1.423 


1.2 


1-4 


1-5 


1.6 


1-7 


1-9 


2.0 


2.1 


2.2 


2.4 


1.424 


2-5 


2.6 


2-7 


2.8 


3-0 


3-1 


3-2 


3-3 


3-5 


3-6 


1-425 


3-7 


3-8 


4.0 


4-1 


4-2 


4-3 


4-5 


4.6 


4-7 


4.8 


1.426 


5-0 


5-1 


5-2 


5-4 


5-5 


5-6 


5-7 


5-9 


6.0 


6.1 


1.427 


6.2 


6.4 


6-5 


6.6 


6.8 


6.9 


7.0 


7-1 


7.2 


7-4 


1.428 


7-5 


7-6 


7-7 


7-9 


8.0 


8.1 


8.2 


8.4 


8.5 


8.6 


1.429 


8-7 


8.9 


9.0 


9-1 


9-2 


9-4 


9-5 


9.6 


9.8 


9-9 


1.430 


10. 


10. 1 


10.3 


10.4 


10-5 


10.6 


10.7 


10.9 


II. 


II. I 


I-431 


11-3 


II. 4 


11-5 


11.6 


II. 8 


II. 9 


12.0 


12.2 


12.3 


12.4 


1-432 


12.5 


12.7 


12.8 


12.9 


13.0 


13.2 


13-3 


13-5 


13.6 


13-7 


1-433 


13-8 


14.0 


14-1 


14-2 


14.4 


14-5 


14-6 


14-7 


14.9 


15.0 


1.434 


iS-i 


15-3 


15-4 


15-5 


15.6 


15.8 


15-9 


16.0 


16.2 


16.3 


1-435 


16.4 


16.6 


16.7 


16.8 


17.0 


17. 1 


17.2 


17-4 


17-5 


17.6 


1.436 


17-8 


17.9 


18.0 


18.2 


18.3 


18.4 


18.5 


18.7 


18.8 


18.9 


1-437 


19.1 


19.2 


19-3 


19-S 


19.6 


19.7 


19.8 


20.0 


20.1 


20.3 


1.438 


20.4 


20.5 


20.6 


20.8 


20.9 


21. 1 


21.2 


21.3 


21.4 


21.6 


1-439 


21.7 


21.8 


22.0 


22.1 


22.2 


22.4 


22.5 


22.6 


22.7 


22.9 


I -44c 


23.0 


23.2 


23-3 


23-4 


23-5 


23-7 


23.8 


23-9 


24.1 


24.2 


I-44t 


24-3 


24-S 


24.6 


24.7 


24.8 


25.0 


2S-I 


25-2 


25-4 


"1-5 


1.442 


25.6 


25.8 


25-9 


26.1 


26.2 


26.3 


26.5 


26.6 


26.7 


26.9 


1.443 


27.0 


27.1 


27-3 


27-4 


27-5 


27-7 


27.8 


27-9 


28.1 


28.2 


1.444 


28.3 


28.5 


28.6 


28.7 


28.9 


29.0 


29.2 


29-3 


29-4 


29.6 


1-445 


29.7 


29.9 


30.0 


30.1 


30-3 


30-4 


30.6 


30-7 


30.8 


30-9 


1.446 


31-1 


31.2 


31-4 


31-S 


31.6 


31.8 


31-9 


32.1 


32.2 


32.3 


1.447 


32-5 


32.6 


32.8 


32-9 


33-0 


33-2 


33-3 


33-5 


33-6 


33-7 


1.448 


33-9 


34-0 


34-2 


34-3 


34-4 


34.6 


34-7 


34-9 


35-0 


35-1 


1.449 


35-3 


35-4 


35-6 


35-7 


35-8 


36-0 


36-1 


36-3 


36-4 


36-S 


1.450 


36-7 


36-8 


37-0 


37-1 


37-2 


37-4 


37-5 


37-7 


37-8 


37-9 


1. 45 1 


38.1 


38-2 


38-3 


38-5 


38-6 


38-7 


38-9 


39-0 


39-2 


39-3 


1.452 


39-5 


39-6 


39-7 


39-9 


40.0 


40.1 


40-3 


40.4 


40.6 


40.7 


1-453 


40.9 


41.0 


41. 1 


41-3 


41.4 


41-5 


41.7 


41.8 


42.0 


42.1 


1-454 


42.3 


42-4 


42-5 


42.7 


42.8 


43-0 


43-1 


43-3 


43-4 


43-6 


I-45S 


43-7 


43-9 


44.0 


44-2 


44-3 


44.4 


44-6 


44-7 


44.9 


45 -o 


1.456 


45-2 


45-3 


45-5 


45-6 


45-7 


45-9 


46.0 


46.2 


46.3 


46-4 


1-457 


46.6 


46.7 


46.9 


47.0 


47-2 


47-3 


47-5 


47-6 


47-7 


47-9 


1.458 


48.0 


48.2 


48.3 


48.5 


48.6 


48.8 


48.9 


49-1 


49-2 


49 4 


1-459 


49-5 


49-7 


49-8 


50.0 


50.1 


50.2 


50-4 


50-5 


50-7 


50.8 


1.460 


51.0 


51-1 


S^-^ 


51-4 


51-6 


51-7 


51.9 


52.0 


52.2 


52-3 


1. 461 


52-5 


52-7 


52-8 


53-0 


53-1 


53-3 


53-4 


53-6 


53-7 


53-9 


1.462 


54-0 


54-2 


54-3 


54-5 


54-6 


54.8 


55-0 


55-1 


55-3 


55-4 


1.463 


55-6 


55-7 


55-9 


56-0 


56.2 


56.3 


56-5 


S6.6 


S6.8 


56-9 


1.464 


57-1 


57-3 


57-4 


57-^' 


57-7 


57-9 


58.0 


58-2 


58-3 


58-5 


1.465 


58.6 


58.8 


58-9 


59-1 


59-2 


59-4 


59-5 


59-7 


59-8 


60.0 


1.466 


60.2 


60.3 


60.5 


60.6 


60.8 


60.9 


61. 1 


61.2 


61.4 


61.5 


1.467 


61.7 


61.8 


62.0 


62.2 


62.3 


62.5 


62.6 


62.8 


62.9 


63.1 


1.468 


63.2 


63-4 


63 5 


63-7 


63.8 


64.0 


64.2 


64-3 


64-5 


64-7 


1.469 


64.8 


65.0 


65.1 


65-3 


65-4 


65-6 


65-7 


65-9 


66.1 


66.2 



92 



FOOD INSPECTION AND ANALYSIS. 



EQUIVALENTS OF INDICES OF REFRACTION AND BUTYRO-REFRAC 
TOMETER READINGS— (Continued). 



Refrac- 








Fourth Decimal of «£), 








tive 






















Index, 






















»D. 





1 


2 


3 


4 


5 


6 


7 


8 


9 










SCALE READINGS 










1.470 


66.4 


66.5 


re. 7 


66.8 


67.0 


67.2 


67-3 


67-5 


67-7 


67.8 


1. 471 


68.0 


68.1 


68 


3 


68.4 


68 


6 


68 


7 


68 


9 


69 


I 


69 


2 


69.4 


1.472 


69-s 


69.7 


69 


9 


70.0 


70 


2 


70 


3 


70 


5 


70 


7 


70 


8 


71.0 


1-473 


71. 1 


71-3 


71 


4 


71.6 


71 


8 


71 


9 


72 


I 


72 


2 


72 


4 


72.5 


1-474 


72.7 


72-9 


73 





73-2 


73 


3 


73 


5 


73 


7 


73 


8 


74 





74-1 


1-475 


74-3 


74-5 


74 


6 


74-8 


75 





75 


I 


75 


3 


75 


5 


75 


6 


75-8 


1.476 


76.0 


76.1 


76 


3 


76.5 


76 


7 


76 


8 


77 





77 


2 


77 


3 


77-5 


1-477 


77-7 


77-9 


78 


I 


78.2 


78 


4 


78 


6 


78 


7 


78 


9 


79 


I 


79-2 


1.478 


79-4 


79-6 


79 


8 


80.0 


80 


I 


80 


3 


80 


5 


80 


6 


80 


8 


81.0 


1.479 


81.2 


81.3 


81 


5 


81.7 


81 


9 


82 





82 


2 


82 


4 


82 


5 


82.7 


1.480 


82.9 


83-1 


83 


2 


83-4 


83 


6 


83 


8 


83 


9 


84 


I 


84 


3 


84-5 


1. 481 


84-6 


84.8 


85 





85.2 


85 


3 


85 


5 


85 


7 


85 


9 


86 





86.2 


1.482 


86.4 


86.6 


86 


7 


86.9 


87 


I 


87 


3 


87 


5 


87 


6 


87 


8 


88.0 


1.483 


88.2 


88.3 


88 


5 


88.7 


88 


9 


89 


I 


89 


2 


■89 


4 


89 


6 


89.8 


1.484 


90.0 


90.2 


90 


3 


90-5 


90 


7 


90 


9 


91 


I 


91 


2 


91 


4 


91.6 


1=485 


91.8 


92.0 


92 


I 


92-3 


92 


5 


92 


7 


92 


9 


93 





93 


2 


93-4 


1.486 


93-6 


93-8 


94 





94-1 


94 


3 


94 


5 


94 


7 


94 


8 


95 





95-2 


1-487 


95-4 


95-6 


95 


8 


96.0 


96 


I 


96 


3 


96 


6 


96 


7 


96 


9 


97.0 


1.488 


97-2 


97-4 


97 


6 


97-8 


98 





98 


I 


98 


3 


98 


5 


98 


7 


98.9 


1.489 


99-1 


99.2 


99.4 


99-6 


99-8 


100. 











The Critical Line. — It should be remembered that the instrument is 
primarily intended for use with butter, and that the prisms are so con- 
structed that the critical line of pure butter is colorless, while various other 
fats and oils, notably oleomargarine, which have greater dispersive powers 
than natural butter, show a colored critical line. When too great dis- 
persion is apparent to render possible an accurate reading, or when the 
critical Hne presents very broad fringes, as with linseed oU, poppyseed 
oil, turpentine, etc., use a sodium light, obtained by the apphcation of 
table salt to the Bunsen gas flame, or the diffused daylight may be re- 
flected in the mirror through a flat bottle filled with a dilute solution of 
potassium bichromate, to give a yellow Hght. 

The advantages of the refractometer for examination of fats and 
oils consist in the convenience with which very accurate determinations 
of the refractive index may be made at any temperature between 10° and 
50° C, inclusive of thermal variations of refractive powers, and also in 
the possibihty which it affords of distinguishing substances by their 
different dispersive powers, rendered visible by the different coloring 
of the critical line, a red-colored critical line being indicative of a relatively 
low dispersive power, a blue line of relatively high dispersion. 



S-J 



THE REFRACTOMETER. 



93 



■^- O _|_| 



[-§ 



s si— S 



SM- -^^-3 



li. f. E — 



cx^ 



§-l 



Variation of Reading with the Temperature. — 
No definite temperature has been adopted as a 
standard for readings of this instrument, but it 
is easy to reduce readings at any temperature to 
terms of any other temperature for purposes of 
comparison. While the change in index of re- 
fraction for 1° C. is the same whatever the 
temperature, as Tolman and Munson have pointed 
out,* the change in scale reading per i° C. de- 
creases as the temperature increases, and varies 
slightly with different oils. For correcting read- 
ing R' at a temperature T' to a reading R at 
temperature T, their formula is R = R' — X{T — 
T'), X being the change in scale reading due to 
change of i° C. in temperature. 

For butter, oleomargarine, beef tallow, lard, 
and other fats reading from 40° to 50° or there- 
abouts on the scale, X = o.55. For oils reading 
between 60° and 70°, like olive, mustard, rapeseed, 
cottonseed, peanut, etc., X = 0.58, and for oils read- 
ing between 70° and 80°, like corn oil, X = o.62. 

The slide rule f shown in Fig. 40, for use with 
the refractometer, has been jointly devised by H- 
C. Lythgoe and the writer, to render unnecessary' 
the use of tables or formulas. The extreme upper 
and lower scale divisions indicate indices of re- 
fraction, and adjacent to these are the scale 
divisions indicating readings on the butyro- 
refractometer. By comparison, therefore, the 
values of either the Abbe or the butyro scale 
may be readily ascertained in terms of the 
other. 

The sliding scale, expressing temperature 
readings in degrees centigrade, is intended to be 
used in connection with the adjacent scale of 
butyro-refractometer readings, to readily express 
the butyro-scale reading of any fat or oil taken 
at a given temperature, in terms of that at any 
other temperature. This is frequently convenient 



Fig. 



40. — Comparative 
fractometer Scale. 



.lai-tuiiicuc. o.cx. * Jour. Am. Chem. Soc, XXIV, p. 755. 

t Mtnufaclure'd by Messrs. Bairdand Tatlock, Ltd., 14 Cross Street, Hatton Garden, 
London. 



94 



FOOD INSPECriOxNT AND ANALYSIS. 



in comparing the work of various observers, where different temperatures 
have been employed. 

The correction for change in w^ on the scale is 0.000365 for 1° C, 
being based on the experimental work of Tolman, Long, Proctor, Lythgoe, 
and the author. 

THE ABBE REFRACTOMETER. 

This instrument, Fig. 41, has a much wider range in reading than 
either the butyro or the Wollny instruments already described, read- 




FiG. 41. — The Abbe Refractometer with Temperature-controlled Prisms. 



ing as it does to the fourth decimal between the limits of 1.3 and 1.7 in 
indices of refraction. The equivalent readings of the Wollny milk fat 
refractometer, in indices of refraction, range from 1.3332 to 1.4220, while 
those of the butyro instrument run from 1.4220 to 1.4895. The Abbe 
instrument is thus necessary for use with the high-refracting essential 



THE REFRACTOMETER. 95 

oils. Its construction is such that the prisms can withstand a higher 
heat than in the case of the butyro-refractometer, and it is hence better 
adapted for the examination of samples having a high melting-point, 
such as beeswax and paraffin. An advantage of the Abbe over the butyro 
instrument lies in the fact that the wide dispersion, inevitable when read- 
ing many substances on the butyro, may be entirely compensated for with 
the Abbe, and a clear sharp line be obtained. The construction of the 
prisms in relation to the heating jacket is similar in both instruments, 
and a film of the substance to be examined is held in the same manner 
between the surfaces of the prisms. 

Construction and Manipulation. — The Abbe refractometer is mainly 
composed of the following parts (see Fig. 41) : 

1. The double Abbe prism AB, which contains the fluid and can 
be rotated on a horizontal axis by means of an alidade. 

2. A telescope OF for observing the border-line of the total reflec- 
tion which is formed in the prism. 

3. A sector .5, rigidly connected with the telescope, on which divisions 
representing refractive indices are engraved. 

The double prism (AB, Fig. 41) consists of two similar prisms of 
flint-glass, each cemented into a metal mount and having a refractive 
index ^£,= 1.75. The former of the two prisms, that farthest from the 
telescope, which can be folded up or removed, serves solely for the 
purpose of illumination, while the border-line is formed in the second flint 
prism. A few drops of the fluid to be investigated is deposited between 
the two adjoining inner faces of the prisms in the form of a thin stratum, 
about 0.15 mm. thick. 

The double prism is opened and closed by means of a screw-head 
V, which acts in the manner of a bayonet catch. In order to apply a 
small quantity of fluid to the prisms without opening the casing, the 
screw V is slackened and a few drops of fluid poured into the funnel- 
shaped aperture of a narrow passage, not seen in the figure. On 
again tightening the screw, the fluid is distributed by capillary action 
over the entire space between the two prisms. This arrangement facili- 
tates the investigation of rapidly evaporating fluids, such as ether solu- 
tions. In the case of viscous fluids (resins, etc.) , a drop of moderate size 
is apphed with a glass rod to the dull prism surface, the double prism 
being opened for the purpose. The prisms are then closed again, and 
before the measurement is proceeded with, the refractometer is left 
standing for a few minutes in order to compensate for any cooling or 
heating of the prisms which might occur while they were separated. 



96 FOOD INSPECTION AND ANALYSIS. 

The arrangement for controlling the temperature of the prisms of 
the Abbe refractometer is essentially after Dr. R. Wollny's plan of enclos- 
ing the prisms in a metal casing with double walls, through which water 
of a given temperature is circulated. 

The border-line is brought within the field of the telescope OF by 
rotating the double prism by means of the alidade in the following 
manner: Holding the sector, the alidade is moved from the initial 
position at which the index points to ^£,= 1.3, in the ascending scale of 
the refractive indices until the originally entirely illuminated field of 
view is encroached upon from the direction of its lower half by a dark 
portion; the line dividing the bright and the dark half of the field then 
is the "border-line." When daylight or lamplight is being employed, 
the border-line, owing to the total reflection and the refraction caused 
by the second prism, assumes at first the appearance of a band of color, 
which is quite unsuitable for any exact process of adjustment. The 
conversion of this band of color into a colorless line sharply dividing 
the bright and dark portions of the field is the work of the compen- 
sator, which consists of two similar Amici prisms of direct vision for 
the D-WxiQ, and rotated simultaneously, though in opposite directions, 
round the axis of the telescope by means of the screw-head M. The 
dispersion of the border-line, which appears in the telescope as a band 
of color, can thus be counteracted by rotating the screw-head M till 
the equal but opposite dispersions are neutralized, making the line color- 
less and sharp. 

The border-line is now adjusted upon the point of intersection of 
the crossed lines by slightly inclining the double prism to the telescope 
by means of the alidade. The position of the pointer on the graduation 
of the sector is then read by the aid of the magnifier attached to the 
alidade. The reading supplies the refractive index w^, of the substance 
under investigation without any computation, and with a degree of 
exactness approaching to within about two units of the fourth decimal. 
Simultaneously, the reading of the scale on the drum of the compensator 
{T in Fig. 41) enables the mean dispersion to be arrived at by means 
of a special table and a short process of computation. 

Influence of Temperature. — As the refractive index of fluids varies 
with their temperature, it is of importance to know the temperature 
of the fluid contained in the double prism during the process of measure- 
ment. 

If, therefore, it is desired to measure a fluid with the highest degree 
of accuracy attainable with the Abb^ refractometer (to within one or 



THE REFRACTOMETER. 97 

two units of the fourth decimal of w^),it is absolutely necessary to bring 
the fluid, or rather the double prism containing it, to a definite known 
temperature, and to be able to control this temperature so as to keep 
it constant to within some tenths of a degree for a period of several 
hours; hence a refractometer principally required for the investiga- 
tion of fluids must be provided with beatable prisms. 

The type of heater shown in Fig. 39. and described in connection 
with the butyro-refractometer on page 88, is equally adapted for con- 
trolling the temperature of the prisms in the Abbe instrument, the flow 
of water entering at D and passing out at E, Fig. 41. 

THE IMMERSION REFRACTOMETER. 

This form of refractometer is of more recent introduction than the 
others made by Zeiss, and has many features that especially commend it 
to the use of the food analyst. The construction of the immersion refrac- 
tometer is such that, as its name implies, it may be immersed directly in an 
almost endless variety of solutions, the strength of which, within Hmits, may 
be determined by the degree of refraction read upon an arbitrary scale. 
Thus, for example, the strengths of various acids and of a variety of 
salt solutions used as reagents in the laboratory, as well as of formaldehyde, 
of sugars in solution, and of alcohol, are all capable of determination by 
the use of the immersion refractometer. 

Figure 42 shows the form used by the writer. P is a glass prism 
fixed in the lower end of the tube of the instrument, while at the top of 
the tube is the ocular Oc, and just below this on a level with the vernier 
screw Z is the scale on which is read the degree of refraction of the liquid 
in which the prism P is immersed. The tube may be held in the hand 
and directly dipped in the liquid to be tested, this liquid being contained 
in a vessel with a translucent bottom, through which the light is reflected. 
The preferable method of use is, however, that shown in the cut. 

A is a metal bath with inlet and outlet tubes, arranged whereby water 
is kept at a constant level. The water is maintained at a constant tem- 
perature by means of a controller of the same type as the refractometer 
heater shown in Fig. 39. In the bath A are immersed a number of 
beakers, containing the solutions to be tested. T is a frame on which is 
hung the refractometer by means of the hook H, at just the right height 
to permit of the immersion of the prism P in the liquid in any of the 
beakers in the row beneath. Under this row of beakers the bottom of 
the tank is composed of a strip of ground glass, through which light is 
reflected by an adjustable pivoted mirror. 



98 



FOOD INSPECTION AND ANALYSIS. 



The temperature of the bath is noted by a delicate thermometei 
immersed therein, capable of reading to tenths of a degree. 

Returning to the main refractometer-tube, i? is a graduated ring or 
collar which is connected by a sleeve within the tube with a compound 
prism near the bottom, the construction being such that by turning 
the collar R one way or the other the chromatic aberration or dispersion of 
any liquid may be compensated for, and a clear-cut shadow or critical line 
projected across the scale. By the graduation on the collar R, the degree of 




Fig. 42. — The Zeiss Immersion Refractoraeter. 

dispersion may be read. Tenths of a degree on the main scale of the in- 
strument may be read with great accuracy by means of the vernier screw Z, 
graduated along its circumference, the screw being turned in each case till 
the critical line on the scale coincides with the nearest whole number. 

The scale of the instrument reads from — 5 to 105, corresponding 
to indices of refraction of from 1.32539 to 1.36640. It should be noted 
th?<t the index of refraction may be read with a greater degree of accuracy 
on the immersion refractometer than on the Abbe instrument. 



THE REFRACTOMETER. 



99 



Manipulation of the Immersion Refractometer. — Before using the 
instrument for the first time, it is necessary to see that the refractometer 
is correctly adjusted. For this purpose the bath A is placed with its 
long side parallel to the window and the mirror turned towards a bright 
sky, the bath is half filled v/ith tap-water, and a beaker filled with dis- 
tilled water is then placed in one of the five holes in the front row imme- 
diately above the mirror. Finally, the refractometer is hung by its 
hook H upon the wire frame, the prism being totally submerged in the 
water contained in the beaker. 

The whole apparatus is now allowed to stand for ten minutes, or until 
the distilled water has acquired the exact temperature of the bath, and 
the ocular is focussed upon the divisions of the scale by turning the 
milled zone of the ocular shell until the lines and numbers are seen quite 
distinctly, the mirror being adjusted so that the light of the bright 
sky is seen directly through the beaker. The upper part of the field 
from —5 to about 15 appears bright, and it is separated from the lower 
dark part by a sharp line of demarcation, if the index on the ring of 
the compensator stands at 5. 



SCALE READING AND INDEX OF REFRACTION OF DISTILLED WATER 
AT 10-30° C, ACCORDING TO WAGNER. 



Temper- 


Scale 


Index of 


fijy Differ- 


Temper- 


Scale 


Index of 


Hjy Differ- 


ature C. 


Reading. 


Refraction, nj). 


ence for 


ature C. 


Reading. 


Refraction, tijy 


ence for 








1° C. 






1° C. 


30 


II. 8 


I. 33196 




19 


14.7 


^ ■ 333075 


8-5 


29 


12 


I 


1.33208 


12.0 


18 


14 


9 


'^■Z2,2,^(^ 


8-5 


28 


12 


4 


1-332195 


"•5 


17-5 


15 


° 


1-33320 


:}«- 


27 


12 


7 


1-33231 


II-5 


17 


15 


I 


1-33324 


26 


13 





1-33242 


II. 


16 


15 


3 


1-333315 


7-5 


25 


13 


25 


1-332525 


10.5 


15 


15 


5 


1-33339 


7 


5 


24 


13 


5 


1-332625 


10. 


14 


15 


7 


1-33346 


7 





23 


13 


75 


1-33272 


9-5 


13 


15 


85 


1-333525 


6 


5 


22 


14 





I. 33281 


9.0 


12 


16 





1-33359 


6 


5 


21 


14 


25 


1.33290 


9.0 


II 


16 


15 


1-33365 


6 





20 


14-5 


1-33299 


9.0 


10 


16 


3 


1-333705 


5 


5 



The reading is taken and the temperature of the distilled water 
noted. Reference to the above table will show if the refractometer 
is correctly adjusted. Should the average of several careful readings 
at a given temperature deviate from that contained in the table, the 
following should be resorted to: 

Readjustment of the Scale. — The ocular end of the refractometer 
hanging on the wire frame is grasped from behind with the thumb and 
forefinger of the left hand, the micrometer drum set to 10, and the steel 



100 FOOD INSPECTION AND ANALYSIS. 

spike, housed in the case of the apparatus, inserted into one of the holes 
of the nickeled cross-holed screw lying on the inner side of the microm- 
eter drum. The spike is then turned anti-clockwise, as seen from the 
rear, whereupon the nickeled milled nut, which governs the micrometer, 
becomes loosened. The temperature of the distilled water in the beaker 
is taken once more to see that it has remained constant, and then the 
table (page 99) is consulted to find the "adjusting number" properly 
belonging to the temperature indicated. By turning the spike, the border- 
line is brought exactly upon the integer scale division appertaining to 
the adjusting number, and the loose micrometer drum is turned so that 
the index accords with the decimal portion of the adjusting number. 
The drum is now held firmly with the thumb and forefinger of the left 
hand, while the nut is screwed up tight again by the right hand, taking 
care, however, that the drum does not wander off the index. Finally, 
the new adjustment is tested by repeated readings. 

Regulating the Temperature. — In many cases it suffices to allow water 
at the temperature of the room to flow slowly from a tank suspended 
high upon the wall through the bath. Should it be required, however, 
to maintain a given temperature (say 20° C.) for hours together con- 
stant to a tenth of a degree, which is frequently desirable if not actually 
necessary, a more elaborate temperature-regulating device should be 
employed. In cold weather, or when the tap-water has a lower tempera- 
ture than that desired, a refractometer heater of the type shown in 
Fig. 39, and described on page 8S, is convenient. 

When, as in the summer, the tap-water temperature is higher than 
that desired for the refractometer bath, there are various ways of success- 
fully controlling the temperature at a lower degree. An ice-water tank 
placed above the level of the bath may be employed, the flow from 
which through the bath is carefully controlled by a pinch-cock or 
otherwise, or is allowed to mingle, under careful regulation before 
entering the bath, with the water from the tap direct or with that from 
the heater. 

Investigation of Solutions in Beakers in Bulk. — The first ten solutions 
are poured into beakers until two-thirds full, and the latter are immersed 
and brought to the temperature of the bath A. When the first five solu- 
tions have been measured, they are taken out of the water-bath and 
the second series of five beakers inserted in their place, bringing at the 
same time a third series into the water-bath. The second series are 
measured and so on. Small gummed labels on the outside prove quite 
satisfactory for numbering the beakers. It is absolutely necessary to 



THE REFRACTOMETER. 101 

compare the temperature of the solutions in the beakers with the water- 
bath from time to time. 

After each immersion, the prism should be wiped dry with a clean, 
soft piece of old linen. 

Investigations of Solutions Excluded from Air. — Quickly evaporating 
liquids, for instance ether solutions, should be treated individually by 
means of the metal beaker adapted to fit the prism end of the refrac- 
tometer. To fill the beaker, the refractometer is held in the left hand 
with the prism pointing upwards, and the metal beaker (M, Fig. 42) 
is set and securely fastened by means of the bayonet joint. It is now 
filled quite full and the cover D carefully fitted and locked. 

The solution is now enclosed, air and water tight. The refractometer 
as before is hung upon the wire frame of the bath, with the metal beaker 
submerged in the bath. 

It is expedient to place the solutions before investigation in closed 
flasks in the nine unoccupied holes in the bath. 

After the measurement, the refractometer is held in the left hand 
with the prism pointing downwards, and the beaker together with its 
cover detached by giving a slight turn with the right hand. The solu- 
tion can be used for other purposes, since it has undergone no change 
in constitution. Finally, the cover is detached from the beaker, and 
cover, beaker, and prism cleaned by simple means, and the refractometer 
made ready for the reception of the next solution, as above. 

Investigations of Small Quantities of Solutions with the Auxiliary 
Prism. — When the solution does not occur in sufficiently large quan- 
tities for investigation in the glass beaker, or when the solution is too 
deeply colored, as in dark beers, molasses, etc., the auxihary prism is 
used. As described under "Solutions Excluded from Air," the metal 
beaker without cover is fitted on the refractometer. The auxiliary prism 
is held horizontally, and, a few drops of the solution having been applied 
to the hypothenuse face, the prism is inserted into the metal beaker, 
held conveniently for the purpose, with its hypothenuse face laid upon 
the polished elliptical face of the refractometer prism, and then locked 
in by the cover. If an insufficient quantity of the solution has been 
taken, the margins of the out-spread drops lying between the two prisms 
can be recognized by looking through the window of the cover on which 
abuts the square pohshed end of the auxiliary prism. It is strongly 
recommended, wherever possible, to apply a sufficiency of the solution, 
so that the space between the prisms is completely filled, otherwise a loss 
in brilliancy occurs, and, under certain circumstances, an unavoidable 



102 



FOOD INSPECTION AND ANALYSIS. 



TABLE OF INDICES OF REFRACTION, n. 



(Compared with 


f-cale Readings of Zeiss 1 


mmersion 


Refractometer, according to Wagner.) 


Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


M^. 


Read- 


«/)• 


Read- 


"£)• 


Read- 


"d- 


Read- 


**D- 


ing. 




ing. 




ing. 




ing. 




ing. 




O.O 


1.327360 


5-0 


1.329320 


10.0 


I -331260 


15.0 


1-333200 


20.0 


I -335168 


O. I 


1-327399 


5-1 


1-3293.50 


10. 1 


I -331299 


15 -^ 


1-333238 


20. 1 


1-335168 


2 


438 


2 


398 


2 


388 


2 


276 


2 


206 


3 


477 


3 


437 


3 


377 


3 


3T4 


3 


244 


4 


516 


4 


476 


4 


416 


4 


352 


4 


282 


5 


555 


5 


515 


5 


455 


5 


390 


5 


320 


6 


594 


6 


554 


6 


494 


6 


428 


6 


358 


7 


633 


7 


593 


7 


533 


7 


466 


7 


396 


8 


672 


8 


632 


8 


572 


8 


504 


8 


434 


9 


711 


9 


671 


9 


611 


9 


542 


9 


472 


l.o 


750 


6.0 


710 


II. 


650 


16.0 


580 


21.0 


510 


I.I 


1.327789 


6.1 


1.329749 


II. I 


I. 331689 


16. 1 


I -333619 


21. 1 


1-335549 


3 


828 


2 


788 


2 


728 


2 


658 


2 


588 


3 


867 


3 


827 


3 


767 


3 


697 


3 


627 


4 


Q06 


4 


866 


4 


806 


4 


736 


4 


666 


5 


945 


5 


905 


5 


845 


5 


775 


5 


705 


6 


984 


6 


944 


6 


884 


6 


814 


6 


744 


7 


t. 328023 


7 


982 


7 


932 


7 


833 


7 


783 


8 


062 


8 


1.330022 


8 


962 


8 


892 


8 


822 


9 


lOI 


9 


061 


9 


t .332001 


9 


931 


9 


861 


a.o 


140 


7.0 


100 


12.0 


040 


17.0 


970 


22.0 


900 


2.1 


r. 328180 


7-1 


1-330139 


12. 1 


1.332078 


17. 1 


I . 334008 


22. 1 


1-335938 


2 


220 


2 


178 


2 


116 


2 


046 


2 


976 


3 


657 


3 


217 


3 


154 


3 


084 


3 


I. 336014 


4 


300 


4 


256 


4 


192 


4 


122 


4 


052 


5 


340 


5 


295 


5 


230 


S 


160 


5 


090 


6 


380 


6 


334 


6 


268 


6 


198 


6 


128 


7 


420 


7 


373 


7 


304 


7 


236 


7 


166 


8 


460 


8 


412 


8 


344 


8 


274 


8 


204 


9 


500 


9 


451 


9 


382 


9 


312 


9 


242 


3-0 


540 


8.0 


490 


13.0 


420 


18. c 


350 


23.0 


280 


3-1 


1.328579 


8.1 


1-330528 


I3-I 


1-332459 


18. 1 


1-334389 


23-1 


I -336319 


2 


618 


2 


566 


2 


498 


2 


428 


2 


358 


3 


657 


3 


604 


3 


537 


3 


467 


3 


397 


4 


696 


4 


642 


4 


576 


4 


506 


4 


436 


5 


735 


5 


680 


5 


615 


5 


545 


5 


475 


6 


774 


6 


718 


6 


654 


6 


584 


6 


514 


7 


813 


7 


756 


7 


693 


7 


623 


7 


553 


8 


852 


8 


794 


8 


732 


8 


662 


8 


592 


9 


891 


9 


832 


9 


771 


9 


701 


9 


631 


4.0 


930 


9.0 


870 


14.0 


810 


19.0 


740 


24.0 


670 


4-1 


1.328969 


9.1 


1.330909 


14. 1 


t. 332849 


19.1 


r- 334779 


24. -I 


1.33670^ 


2 


I .329008 


2 


948 


2 


888 


2 


818 


2 


746 


3 


047 


3 


987 


3 


927 


3 


857 


3 


784 


4 


085 


4 


t .331026 


• 4 


966 


4 


896 


4 


822 


5 


125 


5 


104 


5 


1-333005 


5 


935 


5 


860 


6 


164 


6 


104 


6 


044 


6 


974 


6 


898 


7 


203 


7 


143 


7 


083 


7 


1-335013 


7 


936 


8 


242 


8 


T82 


8 


122 


8 


052 


8 


974 


9 


281 


9 


221 


9 


161 


9 


091 


9 


r. 337012 


S-o 


320 


lO.O 


260 


15.0 


200 


20.0 


130 


25.0 


os» 



THE REFRACTOMETER. 



103 





TABLE OF INDICES OF REFRACTION, 


Hjj — {Continued). 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


n^. 


Read- 


njy. 


Read- 


ftjj. 


Read- 


**D- 


Read- 


f»/3. 


ing. 




ing. 




ing. 




ing. 




ing. 




25.0 


1-337050 


30.0 


I . 338960 


35-0 


I . 340860 


40.0 


1-342750 


45 -O 


1 - 344630 


25.1 


1.337088 


30.1 


t. 338998 


35 • I 


t . 340898 


40. I 


I. 342788 


45-1 


1.344667 


2 


126 


2 


1-339036 


2 


936 


2 


826 


2 


704 


3 


164 


3 


074 


'3 


974 


3 


864 


3 


741 


4. 


202 


4 


112 


4 


1.341012 


4 


902 


4 


778 


S 


240 


5 


150 


5 


ot;o 


5 


940 


5 


818 


6 


278 


6 


188 


6 


088 


6 


978 


6 


8s2 


7 


316 


7 


226 


7 


126 


7 


I. 343016 


7 


889 


8 


354 


8 


264 


8 


164 


8 


054 


8 


926 


9 


392 


9 


302 


9 


202 


9 


092 


9 


963 


26.0 


430 


31.0 


340 


36.0 


240 


41.0 


130 


46.0 


1.345000 


26.1 


c- 337468 


31-1 


1-339378 


36.1 


I. 341278 


41. 1 


[•343167 


46. 1 


1-345037 


2 


506 


2 


416 


2 


316 


2 


204 


2 


074 


3 


544 


3 


454 


3 


354 


3 


241 


3 


III 


4 


582 


4 


492 


4 


.392 


4 


278 


4 


148 


5 


620 


5 


530 


5 


430 


5 


315 


5 


185 


6 


6=;8 


6 


568 


6 


468 


6 


352 


6 


222 


7 


696 


7 


606 


7 


506 


7 


389 


7 


259 


8 


734 


8 


644 


8 


544 


8 


426 


8 


296 


9 


772 


9 


682 


9 


582 


9 


463 


9 


333 


27.0 


810 


32.0 


720 


37-0 


620 


42.0 


500 


47-0 


370 


27.1 


1-337849 


32.1 


I -.339758 


37-1 


1-341657 


42.1 


1-343538 


47-1 


1.345408 


2 


888 


2 


796 


2 


694 


2 


576 


2 


446 


3 


927 


3 


834 


3 


731 


3 


614 


3 


484 


4 


966 


4 


872 


4 


768 


4 


652 


4 


522 


5 


r - 338005 


5 


910 


.5 


805 


5 


690 


5 


560 


6 


044 


6 


948 


6 


842 


6 


728 


6 


598 


7 


083 


7 


986 


7 


879 


7 


766 


7 


636 


8 


122 


8 


I . 340024 


8 


916 


8 


804 


8 


674 


^ 9 


161 


9 


062 


„ 9 


953 


9 


842 


9 


712 


38.0 


200 


33-0 


100 


38.0 


990 


43 -o 


880 


48.0 


750 


28.1 


T- 338238 


33-1 


r. 340138 


38.1 


1.342028 


43-1 


I -343918 


48.1 


1-345787 


2 


276 


2 


176 


2 


066 


2 


956 


2 , 


824 


3 


3M 


3 


214 


3 


104 


3 


994 


3 


861 


4 


352 


4 


252 


4 


142 


4 


1-344032 


4 


898 


5 


190 


5 


290 


5 


180 


5 


070 


5 


935 


6 


428 


6 


328 


6 


218 


6 


108 


6 


972 


7 


466 


7 


366 


7 


256 


7 


146 


7 


1.346009 


8 


504 


8 


404 


8 


294 


8 


184 


8 


046 


9 


542 


9 


442 


9 


332 


9 


222 


9 


083 


29.0 


580 


34-0 


480 


.39 -o 


370 


44 -o 


260 


49 -o 


120 


20.1 


I. 338618 


34-1 


1.3401^18 


.39-1 


1.342408 


/4.1 


1-344297 


49.1 


I. 346158 


2 


656 


2 


556 


2 


446 


2 


334 


2 


196 


3 


694 


3 


594 


3 


484 


3 


371 


3 


234 


4 


732 


4 


632 


4 


522 


4 


408 


4 


272 


5 


770 


=; 


670 


5 


560 


5 


445 


5 


310 


6 


S08 


6 


708 


6 


598 


6 


482 


6 


348 


7 


846 


■7 


746 


7 


636 


7 


519 


7 


386 


8 


884 


8 


784 


8 


674 


8 


556 


8 


424 


9 


922 


9 


822 


9 


712 


9 


593 


9 


462 


30.0 


960 


35-0 


860 


40.0 


750 


45-0 


630 


50.0 


500 



104 



FOOD INSPECTION AND ANALYSIS. 





TABLE OF INDICES OF REFRACTION, 


»^ — {Conlinuei). 




Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


njj. 


Read- 


»»/?• 


Read- 


n^. 


Read- 


n^. 


Read- 


«x>- 


ing. 




ing. 




ing. 




ing. 




ing. 




50.0 


I . 346500 


55-0 


T. 348360 


60.0 


I. 350210 


65.0 


1-352050 


70.0 


1-353880 


50.1 


1-346537 


55-1 


1-348397 


60.1 


1.350247 


65.1 


1.352087 


70.1 


1-353917 


2 


574 


2 


434 


2 


284 


2 


124 


2 


954 


3 


611 


3 


471 


3 


321 


3 


161 


3 


991 


4 


648 


4 


508 


4 


358 


4 


198 


4 


1.354028 


5 


685 


5 


545 


5 


395 


5 


235 


5 


065 


6 


722 


6 


582 


6 


432 


6 


272 


6 


102 


7 


759 


7 


6x9 


7 


469 


7 


309 


7 


139 


8 


796 


8 


656 


8 


506 


8 


346 


8 


176 


9 


833 


9 


693 


9 


543 


9 


383 


9 


213 


Si-o 


870 


56.0 


730 


61.0 


580 


66.0 


420 


71.0 


250 


Si-i 


1-346907 


56.1 


r. 348767 


61. 1 


I. 35061 7 


66.1 


1-352457 


71. 1 


1.354286 


2 


944 


2 


804 


2 


654 


2 


494 


2 


322 


3 


981 


3 


' 841 


3 


691 


3 


531 


3 


358 


4 


I. 347018 


4 


878 


4 


728 


4 


568 


4 


394 


5 


055 


5 


915 


5 


765 


5 


605 


5 


430 


6 


092 


6 


952 


6 


802 


6 


642 


6 


466 


7 


129 


7 


989 


7 


839 


7 


679 


7 


502 


8 


166 


8 


1.349026 


8 


876 


8 


716 


8 


538 


9 


203 


9 


063 


9 


913 


9 


753 


9 


574 


52.0 


240 


57-0 


100 


62.0 


950 


67.0 


790 


72.0 


610 


52.1 


1.347277 


57-1 


1-349137 


62.1 


1-350987 


67.1 


1.352827 


72.1 


1.354646 


2 


314 


2 


174 


2 


I. 351024 


2 


864 


2 


682 


3 


351 


3 


211 


3 


061 


3 


901 


3 


718 


4 


388 


4 


248 


4 


098 


4 


938 


4 


754 


5 


425 


5 


285 


5 


135 


5 


975 


5 


790 


6 


462 


6 


312 


6 


172 


6 


I -353012 


6 


826 


7 


499 


7 


359 


7 


209 


7 


049 


7 


862 


8 


536 


8 


396 


8 


246 


8 


086 


8 


898 


9 


573 


9 


433 


9 


283 


9 


123 


9 


934 


53-0 


610 


58.0 


470 


63.0 


320 


68.0 


160 


73-0 


970 


53-1 


r. 347647 


58.1 


1-349507 


63.1 


1-351357 


68.1 


1-353196 


73-1 


1-355006 


2 


684 


2 


544 


2 


394 


2 


232 


2 


042 


3 


721 


3 


581 


3 


431 


3 


268 


3 


078 


4 


758 


4 


618 


4 


468 


4 


304 


4 


114 


5 


795 


5 


655 


5 


505 


5 


340 


5 


150 


6 


832 


6 


692 


6 


542 


6 


376 


6 


186 


7 


869 


7 


729 


7 


579 


7 


412 


7 


222 


8 


906 


8 


766 


8 


616 


8 


448 


8 


258 


9 


943 


9 


803 


9 


653 


9 


484 


9 


294 


54-0 


980 


59-0 


840 


64.0 


690 


69.0 


520 


74-0 


330 


541 


I. 348018 


59-1 


1-349877 


64.1 


I. 351726 


69.1 


1-353556 


74-1 


1-355366 


2 


056 


2 


914 


2 


762 


2 


592 


2 


402 


3 


C94 


3 


951 


3 


798 


3 


628 


3 


438 


4 


132 


4 


988 


4 


834 


4 


664 


4 


474 


5 


170 


5 


1-350025 


5 


870 


5 


700 


5 


510 


6 


208 


6 


062 


6 


906 


6 


736 


6 


546 


7 


246 


7 


099 


7 


942 


7 


772 


7 


582 


8 


284 


8 


136 


8 


978 


8 


808 


8 


618 


9 


322 


9 


173 


9 


I. 352014 


9 


844 


9 


659 


S5-0 


360 


60.0 


210 


65.0 


C50 


70.0 


880 


7S-0 


690 



THE REFRACTOMETER. 



105 



TABLE OF INDICES OF REFRACTION, n^—(Contmiied). 



Scale 




Scale 




Scale 




Scale 




Scale 




Read- 


»»£)• 


Read- 


»«£>- 


Read- 


«£,. 


Read- 


«/)- 


Read 


n,j. 


ing. 




ing. 




ing. 




ing. 
90.0 




ing. 




75-0 


1-355690 


.*^o.o 


1-357500 


85.0 


I - 359300 


1 .361090 


95 • 


1 . 362870 


75-1 


I 355727 


80.1 


1-357536 


85.1 


1-359336 


90. I 


I . 361126 


95-1 


I .362Q06 


2 


764 


2 


572 


2 


372 


2 


162 


2 


042 


3 


801 


3 


608 


3 


408 


3 


198 


3 


978 


A 


838 


4 


644 


4 


444 


4 


234 


4 


I -363014 


5 


875 


5 


680 


5 


480 


5 


270 


5 


050 


6 


912 


6 


716 


6 


516 


6 


306 


6 


086 


7 


949 


7 


752 


'7 


552 


1 


342 


7 


122 


8 


986 


8 


788 


8 


588 


8 


378 


8 


158 


9 


1.356023 


9 


824 


9 


624 


9 


414 


9 


194 


76.0 


060 


81.0 


860 


86.0 


660 


91 .0 


450 


96.0 


230 


76.1 


1.356096 


81. 1 


1-357896 


86.1 


1 . 359696 


91.1 


I. 361486 


96.1 


1-363256 


2 


132 


2 


932 


2 


732 


2 


522 


2 


292 


3 


168 


3 


968 


3 


768 


3 


558 


3 


328 


4 


204 


4 


I . 358004 


4 


804 


4 


594 


4 


364 


5 


240 


5 


040 


5 


840 


5 


630 


5 


400 


6 


276 


6 


076 


6 


876 


6 


666 


6 


436 


7 


312 


7 


112 


7 


912 


7 


702 


7 


472 


8 


348 


8 


148 


8 


948 


8 


738 


8 


518 


9 


384 


9 


184 


9 


984 


9 


774 


9 


554 


77.0 


420 


82.0 


220 


87.0 


I . 360020 


92.0 


810 


97-0 


590 


77.1 


1.356456 


82.1 


1.358256 


87.1 


1.360056 


92.1 


I 361846 


97-1 


I . 363625 


2 


492 


2 


292 


2 


092 


2 


882 


2 


660 


3 


528 


3 


328 


3 


128 


3 


918 


3 


695 


4 


564 


4 


364 


4 


164 


4 


954 


4 


730 


s 


600 


5 


400 


5 


200 


5 


990 


5 


765 


6 


636 


6 


436 


6 


236 


6 


I .362026 


6 


800 


7 


672 


7 


472 


7 


272 


7 


062 


7 


835 


8 


708 


8 


508 


8 


308 


8 


098 


8 


870 


9 


744 


9 


544 


9 


344 


9 


134 


9 


905 


78.0 


780 


83.0 


580 


88.0 


380 


93-0 


170 


98.0 


940 


78.1 


I. 356816 


83.1 


1-358616 


88.1 


I. 36041 6 


93-1 


1.362205 


98.1 


1-363975 


2 


852 


2 


652 


2 


452 


2 


240 


2 


I. 364010 


3 


888 


3 


688 


3 


488 


3 


275 


3 


045 


4 


924 


4 


724 


4 


524 


4 


310 


4 


080 


5 


960 


5 


760 


5 


560 


5 


345 


5 


IIS 


6 


996 


6 


796 


6 


■596 


6 


380 


6 


160 


7 


1-357032 


7 


832 


• 7 


632 


7 


415 


7 


19s 


8 


068 


8 


868 


8 


668 


8 


450 


8 


230 


9 


104 


9 


904 


9 


704 


9 


485 


9 


265 


79.0 


140 


84.0 


940 


89.0 


740 


94.0 


520 


99.0 


290 


79.1 


1-357176 


84.1 


1.358976 


89.1 


1-360775 


94-1 


I 362555 


99.1 


1-364325 


2 


212 


2 


1.359012 


2 


810 


2 


590 


2 


360 


3 


248 


3 


048 


3 


845 


3 


625 


3 


395 


4 


284 


4 


084 


4 


880 


4 


660 


4 


430 


5 


320 


5 


120 


5 


915 


5 


695 


5 


465 


6 


356 


6 


156 


6 


950 


6 


730 


6 


500 


7 


392 


7 


192 


7 


985 


7 


765 


7 


535 


8 


428 


8 


228 


8 


I. 361020 


8 


800 


8 


570 


9 


464 


9 


264 


9 


055 


9 


835 


9 


605 


80.0 


500 


85.0 


300 


90.0 


090 


95 


870 


100. 


640 



106 



FOOD INSPECTION AND ANALYSIS. 



degradation of the sharpness of the border-line. On the other hand, 
with a sufficient quantity of solution, the border-line is surprisingly sharp. 

The refractometer is now suspended on the frame, and the measure- 
ment proceeded with as before described. After measurement, the cover 
is first removed, and the prism allowed to fall into the hollow of the 
hand, then the beaker is removed to enable the refractometer to be 
conveniently cleaned. 

Strengths of Various Solutions. — The most extensive work on the 
quantitative determination of the strength of a large number of common 
aqueous solutions with the immersion refractometer has been done by 
Wagner, who has published a large number of tables. These tables 
show the percentage strength (grams per loo cc. at 17.5° C.) of a large 
number of salt solutions and of acids, corresponding to the range of scale 
readings of the instrument, as well as of cane sugar, dextrose, formalde- 

SCALE READINGS ON IMMERSION REFRACTOMETER OF VARIOUS STAND- 
ARD REAGENTS USED IN VOLUMETRIC ANALYSIS.* 



Temperature C. 



16°. 17°. 17.5°- i8°- 19°. 20°. 21". aa' 



Hydrochloric acid: 

Normal 

Tenth-normal 

Sulphuric acid: 

Normal 

Fifth-normal 

Tenth-normal 

Oxalic acid: 

Half-normal. « 

Tenth-normal 

Potassium bitartrate: 

Tenth-normal 

Potassium hydroxide: 

Normal 

Tenth-normal 

Sodium hydroxide: 

Tenth-normal 

Sodium thiosulphate ; 

Tenth-normal 

Potassium bichromate: 

Tenth-normal 

Silver nitrate: 

Tenth-normal 

Sodium chloride: 

Tenth-normal 

Ammonium sulphocyanate : 

Tenth-normal 



37-45 
17.80 

30.60 
18.75 
17-15 

22.45 
17-15 

17-75 

43-90 
18.45 

18.50 
24.20 

17-75 
20.20 
18.20 
20.60 



37.20 
17.60 

30.40 
18.60 
16.95 

22.30 
16.95 

17-55 

43-65 
18.30 

18.35 
24.05 

17-55 
20.05 
18.00 
20.45 



36.85 
17-30 

30. 10 
18.30 
16.65 

22.00 
16.65 

17-25 

43-25 
18.00 

18.05 
23-75 
17-25 
19-75 
17.70 
20.15 



36.70 
17.20 

29-95 
18.20 

16.55 

21.90 
16.55 

17-15 

43.10 
17.90 

17-95 
23-65 
17-15 
19.65 
17.60 
20.05 



36-45 
17.00 

29-75 
18.00 

16.35 

21 .70 
16.35 

16.95 

42.80 
17.70 

17-75 
23-45 
16.95 

19-45 
17.40 
19.85 



35-70 
16.30 

29.00 
17-30 
15-65 

21.00 
15-65 

16.25 

41-95 
17.00 

17-05 
22.70 
16.25 

18.75 
16.70 

19-15 



* According to Wagner, all these solutions were made up at 17.5° C. Readings at different t«m> 
peratures are given for convenience. 



THE REFRACTOMETER. 



107 



hyde, alcohol, etc. All these observations have been based on the Mohr 
liter, at a temperature of 17.5°. More convenient for the American 
analyst would be tables based on the use of a higher temperature, say 20°, 
and the analyst is recommended to work out his own standards for com- 
parison, at the temperature best suited to his special locality and conven- 
ience. The instrument is especially useful in preparing normal and tenth- 
normal solutions. 

The table on page 106, from Wagner, shows the strength of various 
common laboratory reagents. 



SCALE READINGS AT TEMPERATURES FROM 10-30° C. 
Corrected to 17.5°, According to Wagner. 



No. 


X. 


2. 


3- 


4- 


5- 


6. 7- 


8. 


9. 


10. 


It. 


12 & 13. 


No. 


fed 


Scale Reading at 17.5° C. 


id 




IS. 


30. 


25- 


30. 


35. 


40. 


4S. 


50. 


60. 


70. 


80. 


90 <k 100. 


E5 


30 


^•3.20 


3-15 


3-25 


3 -40 


3-55 


3-65 


3-90 


4-05 


4.20 


4.60 


4.80 


S-25 


30 


29 
28 
27 
26 


3.90 
«.6o 
i.30 
4.00 


2.85 

2-55 
2.25 
1.95 


2-95 
2.65 

2-35 
2.05 


3.10 
2.80 
2.50 
2.20 


3-25 
2-95 
2.65 

2-35 


3-35 
3-05 
2-75 
2.45 


3 55 
3-25 
2-95 
2-55 


3-75 
3-45 
3-15 
2.80 


3 90 
3.60 

3-3° 
2-95 


4-25 
3-9° 
3-50 
3.10 


4-45 
4.10 

3-75 
3-30 


4.85 

4-5° 
4.10 

3-65 


29 
28 
27 
26 


25 


«-75 


1-75 


1.80 


1.90 


2.05 


2-15 


2.25 


2-45 


2.60 


2. 70 


2-95 


3.20 


25 


24 

23 
22 
21 


» 50 
I 25 

I.iO 

0-75 


1-45 
1.25 
1. 00 
0-75 


1-55 
1.30 
x.os 
0.80 


1.60 

1-35 
1 . 10 
0.85 


1-75 
1-45 
1-15 
0.90 


1.85 

1-55 
1.25 

0-95 


1-95 
1.65 
1.30 
1.05 


2.10 

1-75 
1 .40 
1.05 


2.25 
1 .90 

1-55 
1.20 


2-35 
2.00 

1.65 

1-25 


2-55 
2.15 

1-75 
1-35 


2-75 
2-35 
1.90 

1-45 


24 

23 
22 
21 


20 


0.50 


0.50 


0-5S 


0.60 


0.65 


0.65 


0-75 


0-75 


0.85 


0.90 


0-95 


1.05 


20 


19 
18 


0.30 

O.IO 


0.30 
0. 10 


0.30 
o.io 


0-35 
0-15 


0.40 
0.15 


0.40 
0.15 


0.45 
0.15 


0-45 
0.15 


0-45 
015 


0-55 
0.20 


0'55 
0.20 


0.60 
0.20 


19 
18 


17-5 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


0.00 


17-5 


17 
16 


— 0. 10 

0.30 


0. 10 
0.30 


O.IO 

0.30 


0. 10 
0.30 


O.IO 

0-35 


O.IO 

0-35 


0.15 
0.40 


0.15 
0-45 


0-15 
0.45 


0.15 
0.50 


0.20 
0-55 


0.20 
0-55 


17 
16 


15 


0.50 


0-45 


0.45 


0.50 


0.60 


0.60 


0.65 


0-75 


0-75 


0.80 


0.85 


0.90 


15 


14 
13 
12 


0.70 

0.85 

1. 00 


0.60 
0-75 


0.60 
0-75 


0.70 
0.85 


0.80 
1. 00 


0.85 
1. 10 


0.90 
1-15 


0-95 
1.20 


1.05 
1-35 


1. 10 
1.40 


1-25 
1-55 


1.25 
1.60 


14 
13 


II 




















































10 


1.25 




















































No. 


I. 


2. 


3. 


4- 


s. 


6. 


7. 


8. 


9- 


10. 


II. 


-a & 13. 


No. 



CHAPTER VIL 
MILK AND ITS PRODUCTS. 
MILE. 

Characters and Constituents.— Milk is the secretion of the mam- 
mary glands of female mammals for the nourishment of their young. 
Containing as it does all the requisites for a complete food, i.e., sugar, fat, 
proteins, and mineral ingredients, combined in appropriate proportion, 
there is ample reason why it occupies so high a place in the scale of human 
foods. It is a yeJlowish-white opaque fluid, denser than water, contain- 
ing in complete solution the sugar, soluble albumin, and mineral content, 
and, in less complete solution, the casein, while the fat-globules are held in 
suspension in the serum, forming an emulsion. 

The specific gravity of pure milk ranges from 1.027 to 1.035. 

Milk from various animals has the same general physical properties 
and the same ingredients, differing, however, in percentage composition. 
Of all the varieties, the milk of the cow is by far the most important from 
its universal use, and, unless otherwise qualified, the term milk wherever 
it occurs in this volume will be understood to mean cow's milk. 

Acidity. — When perfectly fresh, milk of carnivorous mammals is, 
as a rule, acid to litmus, while human milk is alkaline. Cow's milk, 
when freshly drawn, reacts acid to phenolphthalein, and alkaline to methyl 
orange and lacmoid, but amphoteric to litmus, i.e., reacts acid to blue 
and alkaline to red litmus paper. Bordas and Touplain * believe the 
original acidity to phenolphthalein is due to casein; as a result of the 
decomposition of lactose, before lactic acid appears, casein is separated 
from calcium caseinate and monocalcium phosphate is formed from the 
dicalcium salt. It soon becomes distinctly acid, and the acidity increases 
as the lactose gradually becomes converted into lactic acid. 

Microscopical Appearance. — Under the microscope pure milk shows 
a conglomeration of various-sized fat globules having a pearly lustre. 

* Compt. rend., 152, 1911, p. 1274. 
108 



MILK AND ITS PRODUCTS. 109 

These globules vary from o.ooi to o.oi mm. in diameter, averaging about 
0.C05 mm., although the size varies greatly with the breed of cow (p. 115), 
period of lactation, and other conditions. Whether or not the globules 
have a special membranous coating is still in dispute. 

Leucocytes, identical with or related to the white corpuscles of the 
blood, are present in all milk,* but according to Doane are indicative of 
udder diseases when in masses. Some authors believe that the leucocyte 
count is of diagnostic value. 

When examined under very high powers, it is possible to distinguish 
bacteria in the milk, the number to be seen depending greatly on the 
time that has elapsed since the milk was drawn from its source, as well 
as on the surroundings, the conditions of handling, exposure, etc. 

Certain bacteria are present in the milk before it is drawn from the 
udder, but these are few in number and kind compared with those intro- 
duced during or after milking. 

Color. — The yellow color of milk is imparted to it by the fat globules, 
and varies greatly in milk from different breeds of cattle, as well as in 
milk from the same cow at different seasons, being, as a rule, paler during 
the winter or stall-fed months, and having its greatest intensity soon after 
the cow is put out to pasture. The nature of the color is considered in 
the section on butter (Chapter XIII). 

Fat. — This is the most variable constituent of milk, being present 
in amounts ranging from less than 2.5 to nearly 7%. For the chemical 
composition and characteristics of milk fat, see Butter. 

Lactose or Milk Sugar, the carbohydrate of milk, is normally present 
in amounts varying from 3 to 5 per cent. 

Proteins of Milk. — Casein, a phosphoprotein, constitutes about 80% 
of the entire proteins of milk, being present in an average sample to the 
extent of about 3%. It exists in combination as calcium caseinate, and 
probably does not form a perfect solution in the milk, but is rather diffused 
therein in a somewhat colloidal form, being so finely divided, however, 
as to be incapable of separation by filtration while the milk is fresh. On 
coagulation with rennet paracasein is formed. 

Pure casein is a white, odorless, and tasteless solid, sparingly soluble 
in water, and insoluble in ether and alcohol. It is readily soluble in dilute 
alkalies. Strong acids also dissolve it, but its character is changed. From 

* Doane, Md. Agric. Exp. Sta., Bui. 102, 1905, p. 205; Savage, Jour. Hyg. (Cambridge), 
6, 1906, p. 173. 



110 FOOD INSPECTION AND ANALYSIS, 

alkaline solution it is precipitated without change by neutralizing with 
acid. Its specific rotation in aqueous solutions is [«]£>= —8c (Hoppe- 
Seyler) . 

Laclalhumin is the soluble albumin of milk, existing therein to the 
extent of about 0.6% and forming about 15% or more of the milk proteins. 
It much resembles the albumin of eggs, being coagulated at 72° to 84° C. 
It is readily soluble in water. Its specific rotation is [a]z)= - 37. 

Lactoglohulin has been discovered by Emmerling as a constituent in 
milk, but exists in traces only. According to Babcock, it may be separated 
from milk whey by carefully neutralizing with sodium hydroxide, and 
afterwards saturating with magnesium sulphate. It much resembles the 
globulin of blood serum, being coagulated at 67° to 76° C. 

Fibrin. — Babcock has discovered in milk very minute traces of a 
substance analogous to the fibrin of blood. This substance, it is claimed, 
forms a part of the slime found in the separator-bowl of a centrifugal 
skimmer. 

Other Nitrogenous Substances. — Besides the above normal constituents 
of milk, certain bodies may be formed by proteolytic action during fer- 
mentation, such, for example, as caseoses and peptones, formed for the 
most part by the decomposition of a part of the casein. Galactin is a 
gelatin-like body of the nature of peptone, occurring in traces in milk. 
Besides these, minute traces of amino-bodies, such as creatin, urea, and 
allantoin, are sometimes present, and also ammonia. 

Citric Acid has been found to exist in milk, probably in combina- 
tion with certain of the mineral constituents, being present to the extent 
of about 0.1%. 

Other Organic Constituents reported in milk are lecithin, cephalin, 
cholesterol, acetone, and thiocyanates. 

The Enzymes of Milk have been subjects of extensive investigation. 
The presence or amount of four of these, namely, peroxidase, reductase, 
aldehyde reductase, and catalase, are of considerable importance in sani- 
tary milk examination. 

Peroxidase originates in the mammary glands. Since it is destroyed 
at about 80° C, it is the basis of various tests for distinguishing raw from 
heated milk. Peroxidase acts in the presence of hydrogen peroxide, 
from which it splits off an atom of active oxygen, the latter combining 
with various chromogens (page 173). 

Reductase is indicated by the decolorizing power of milk for certain 
dyes. Since reductase is believed to be a product of bacteria, the tests 



MILK AND ITS PRODUCTS. 



Ill 



W 



O S rs 



TJ 






T) 


rt 










rt 


fi) 


0) 






^ 


1-1 



>, " C '-' >. 3 i3 



O .S 5 S 



O 



C c t^ 

:S ^ 2 

O Ph C/J 



S m m 



C . .-5 

■3 ">, .S 

^ I-, u 

cx cx &, 
U U U 



10 M 

4 d 



mO O t^Mj-^o O 
f-.t-~.^M o N ^-O 
mOmooOwm 

00006606 



cS 3 



Si £ y -^ a -"^ -^ 



s § ° 
.2 c S 

O 



.2 -S 






o 

P 3 ^ J3 






m 



O -CI 

< o 



112 FOOD INSPECTION AND ANALYSIS. 

are used for detecting pollution as an adjunct to bacteriological examina- 
tion. 

Aldehyde Reductase is a term applied to the enzyme which decolorizes 
methylene blue in the presence of formaldehyde, the latter inhibiting, it 
is believed, the action of bacteria so that the decolorizing action is due largely 
to the enzyme. The test furnishes information as to whether or not milk 
has been properly pasteurized at 63° C. (page 174). 

Catalase splits up two molecules of hydrogen peroxide into two mole- 
cules of water and one of oxygen. The latter may be measured or other- 
wise determined. The enzyme has been shown to be derived from leu- 
cocytes and the test is therefore useful in detecting milk from diseased 
udders (mastitis, etc.). 

Average Composition of Milk. — On page 11 1 is given in schematic 
form the average percentages of the principal constituents as arranged 
by Babcock. 

The following table shows the forms in which, according to Van Slyke 
and Bosworth,* the constituents are probably combined: 

Fat 3-90 

Lactose 4-9° 

Proteins combined with calcium 3 . 20 

Dicalcium phosphate (CaHP04) o - ^75 

Calcium chloride (CaCb) o. 1 19 

Monomagnesium phosphate (MgH4P208) o . 103 

Sodium citrate (NasCeHsOT) c . 222 

Potassium citrate (K3C6H5O7) 0.052 

Dipotassium phosphate (K2HPO4) o . 230 

Total solids 12.901 

Composition of the Ash of Milk.— The ash of milk does not truly 
represent the mineral content, since, in the process of incineration, the 
character of some of the constituents is altered by oxidation and otherwise. 

The composition of the ash of the typical milk sample, the full analysis 
of which is given on page iii, would be about as follows: 



* N. Y. State Agric. Exp. Sta., Tech. Bui. 39, 1914. 



MILK AND ITS PRODUCTS. 



113 



Potassium oxide 25 .02 

Sodium oxide 10.01 

Calcium oxide 20.01 

Magnesium oxide 2 .42 

Iron oxide 0.13 

Sulphur trioxide 3 . 84 

Phosphoric pentoxide 24. 29 

Chlorine 14. 28 



100.00 



Composition of Milk of Different Animals. — A summary of analyses 
of human, goat's, ewe's, mare's, and ass's milk, as well as of cow's milk 
for comparison, is given in the following table, the figures for human milk 
being compiled by Richmond,* those for the milk of other animals by 
Konio;: 





No. of 
Anal- 
yses. 


Specific 
Gravity. 


Water. 


Fat. 


Lactose 


Total 
Pro- 
tein. 


Casein. 


Albu- 
min. 


Ash. 


Fuel 

Value 

per Lb., 

Calories 


Cow's milk .... 


800 




















Maximum . . . 




1.0370 


90-32 


6.47 


6. 12 


6.40 


6.29 


1.44 


I. 21 




Minimum . . . 




1.0264 


80.32 


1.67 


2. II 


2.07 


1.79 


0.25 


0-35 




Average 




IO31S 


87.27 


3-64 


4.88 


3-55 


3.02 


0.53 


0.71 


310 


Human milk. . . 


94 




















Maximum. . . 




1.0426 




9-oS 


8.89 


5-56 






0.50 




IMinimum. . . 




1.0240 




0.47 


4. 22 


0.85 






0.09 




Average 




IO313 


88.20 


3-30 


6.80 


1-50 






0.20 


295 


Goat's milk. . . . 


200 




















Maximum. . . 




1.0360 


90. 16 


7-55 


5-77 




3-94 


2.01 


1.06 




Minimum. . . 




1.0280 


82.02 


3-10 


3.26 




2-44 


0.78 


0-39 




Average 




I 0305 


85.71 


4-78 


4.46 


4.29 


3.20 


1.09 


0.76 


364 


Ewe's milk .... 


32 




















Maximum. . . 




I 0385 


87.02 


9.80 


7-95 




5-69 


1-77 


1.72 




Minimum. . . 




1.0298 


74-47 


2.81 


2.76 




3-59 


0.83 


0.13 




Average 




I. 0341 


80.82 


6.86 


4.91 


6.52 


4-97 


1-55 


0.89 


502 


Mare's milk . . . 


47 




















Average 




I 0347 


90.78 


I. 21 


5.67 


1-99 


.1.24 


0.75 


0.35 


194 


Ass's milk 


5 




















Average 




1.0364 


89.64 


1.64 


5-99 


2, 22 


0.67 


1-55 


0-51 


222 



Fore Milk and Strippings. —Unless a portion drawn from the well- 
mixed or whole complete milking of an animal is taken for analysis, one 



Dairy Chemistry, London, 1914, p. 394. 



114 



FOOD INSPECTION AND ANALYSIS. 



does not get a fair representative sample of the milk, for it is a well-known 
fact that the first portion of milk drawn from the udder, termed the " fore 
milk," is very low in fat, while the last portions or " strippings " con- 
tain a very high fat content, sometimes exceeding io% fat. The following 
analyses show the difference between fore milk and strippings in two 
cases : 



Per Cent 
Water. 



Per Cent 
Solids. 



Per Cent 
Fat. 



(i) Fore milk. 

Strippings 
(2) Fore milk. 

Strippings 



88.17 
80.82 

88.73 
80.37 



11.83 
19.18 
11.27 
19.63 



1.32 

963 

1 .07 

10.36 



The percentages of protein, lactose, and ash are nearly the same in 
both fore milk and strippings. 

Colostrum.— The milk given by cows and other mammals for two or 
three days after the birth of young is termed colostrum, and diiTers ma- 
terially in composition from normal milk. It is yellow in color, of an 
oily consistency, and has a pungent taste. It acts as. a purge upon the 
young. Under the microscope may be seen fat globules, which are larger 
than at subsequent stages of lactation, and circular cells (0.005 ""0-025 
mm.) related to, if not identical with, the leucocytes or white corpuscles 
of the blood. It is very high in albumin, which seems to be similar to 
blood albumin. The following analyses were made by Engling, showing 
the composition of colostrum from a cow eight years old : 



Time after Calving. 


Specific 
Gravity. 


Fat. 


Casein. 


Albumin. 


Lactose. 


Ash. 


Total 
Solids. 


Immediately 


1.068 
1.046 

I 043 
1.042 

1 .035 


3-54 
4.66 

4-75 

4.21 

4.08 


2.65 
4.28 

450 
3-25 

3-33 


16.56 
932 
6.25 

2.31 
1.03 


3.00 
1.42 
2.8s 
3 46 
4.10 


1. 18 

1-55 
1.02 
0.96 
0.82 


26.93 
21.23 

19-37 
14.19 
13 36 


After 10 hours 

" 24 " 

" 48 " 

" 72 " 



The average of twenty-two analyses of colostrum from different cows 
by Engling showed total solids 28.31, fat 3.37, casein 4.83, albumin 15.85, 
lactose 2.48, ash 1.78. 

Changes in Composition During Lactation. — Crowther and Ruston * 
in Scotland, and Eckles and Shaw f in the United States have found 



* Trans High. Agric. Soc. Scotland, v. 23, 191 1, p. 93. 
t U. S. Dept. of Agric, Bur. of Anim. Ind., Bui. 155, 191J 



MILK AND ITS PRODUCTS. 



115 



tRat fat, protein, and total solids are highest in the earliest and latest 
stages of lactation, while ash remains practically constant throughout the 
period. LactosQ according to Crowther and Ruston decreases steadily 
after the first month or so, while according to Eckles and Shaw the only 
change attributable to the stage of lactation is a slight decline toward 
the end. The last named authors note that the fat globules decrease 
sharply in size during the first 6 weeks, remain practically constant 5 
to 6 months, then decrease more rapidly to the end of the period. 

Milk of Young and Old Cows.— Less data are available on this point 
than on the other common factors influencing composition. La Cour* 
found that the milk from young cows was generally higher in fat content 
than that of old cows. 

Milk of Different Breeds. — The following table and the table on 
page 152 give analyses showing the general characteristics of the milk of 
single cows o"^ several well-known breeds. The following results by 
Eckles and Shaw f are the averages of determinations made throughout 
the whole period of lactation. 

AVERAGE COMPOSITION OF MILK OF INDIVIDUAL COWS REPRESENTING 
FOUR BREEDS (ECKLES AND SHAW). 



Breed. 



Age of 
Cow. 



Total 
Solids. 



Fat. 



Total 
Pro- 
tein. 



Casein 



Lac- 
tose. 



Relative 
Vol. of 
Fat 
Glo- 
bules. 



Total 
Milk 
Yield. 



Holstein . . 
Holstein . . 
Holstein. . 

Average 
Ayrshire . . 
Ayrshire. . 

Average 

Jersey 

Jersey. . . 
Jersey 

Average 
Shorthorn 
Shorthorn 
Shorthorn , 

Average 



Yrs. Mos. 
5 3 

5 o 

3 8 

4 8 

3 8 

4 8 
4 2 

6 10 
8 I 

4 
8 9 
4 4 

4 II 
6 o 

5 I 



II 



12. 12 
10.73 
11-35 
11.38 
12.08 
12. 71 
12.41 
14.09 

13-34 
15.02 
14.09 
13.08 
13.01 
12.17 
12.69 



23 


3 


93 


2 


10 


3 


.09 


2 


SI 


3 


85 


3 


68 


3 


87 


3 


64 


3 


36 


3 


95 


3 


89 


3 


13 


3 


37 


3 


73 


3- 



.00 

,70 

21 

•93 
. II 

■33 
25 
70 
27 

-97 
.64 
.40 

-49 
,28 

-38 



2-49 
2. II 

2-49 
2.36 
2.62 
2.81 
2. 70 

2-93 
2.65 

3-13 
2-93 
2.74 
2.87 
2.62 
2-74 



127 
164 

134 

142 

141 
160 
150 
309 
336 
338 
328 
3" 
353 
211 
282 



lbs. 



8994 
8814 
8831 
6275 
6382 
6329 
5429 
6115 
5733 
5 759 
5172 
4449 
6539 
5387 



* Tidskr. Landokon, 13, 1894, p. 303. 

t U. S. Dept. of Agric, Bur. of Anim. Ind., Bui. 156, 1913. 



116 FOOD INSPECTION AND ANALYSIS. 

Influence of Feed on Composition. — A great amount of work has been 
done on this subject, but the results are conflicting and not such as can 
be readily summarized. In general it may be stated that the influence 
exerted by the feed, except under abnormal conditions or in the case of 
a few special feeds, is slight compared with that of breed. This point 
is worthy of consideration in view of the common practice of attributing 
to feed abnormalities really due to adulteration. 

Intervals Between Milking. — Several observers have shown that the 
longer the intervals between milkings the lower the percentage of fat. 
When the milking night and morning is at the same hour there is little 
difference. 

Frozen Milk. — Since it is the water that freezes, it follows that in 
partially frozen milk the unfrozen portion becomes concentrated. This 
is borne out by the following figures of Richmond : * 

Frozen Portion. Unfrozen Portion. 

Specific gravity i .0090 i .0345 

Water 96-23 85 . 62 

Fat 1.23 4.73 

Lactose 1.42 4.95 

Protein 91 3.90 

Ash .21 .80 

The freezing point of milk is considered on page 153. 

Fermentations of Milk.— These are due to the action of bacteria 
of various kinds, the most common being the lactic bacilli. 

The Souring of Milk is caused by the action of a large number of 
species of acid-forming bacteria, chief among which is the Bacillus acidi 
lactici, which multiplies faster than other bacteria in raw milk under 
favorable conditions of temperature. Part of the milk sugar is acted 
on and transformed, first into dextrose and galactose, the latter sugar 
subsequently forming lactic acid, as follows : 

(1) Ci2H220il,H20 = C6Hi,>06 + C6Hi206 

Lactose Dextrose J Galactose 

(2) C6Hi206=2C3H603 

Galactose Lactic acid 

In experiments by Van Slyke and Bosworth,f 22% of the lactose was 
decomposed, of which amount 88.5% went into lactic acid. The citric 

* Analyst, 18, 1893, P* 53- 

t N. Y. State Agric. Exp. Sta., Tech. Bui. 18, 1916. 



MILK AND ITS PRODUCTS. 117 

acid was entirely decomposed into acetic acid and carbon dioxide. Al- 
bumin was so changed as to pass completely through a porcelain filter. 
Calcium caseinate reacted with the lactic acid, forming the free protein, 
which precipitated, and calcium lactate, which remained in solution. 

Abnormal Fermentation. — Through the agency of micro-organisms 
that may develop under certain conditions, various changes are produced 
in milk that to some extent alter its character. Thus bitter milk is some- 
times produced as the result of some organism as yet but little understood. 

Occasionally milk is found possessing a peculiarly thick and slimy 
consistency, whereby it may be drawn out in threads, by dipping a spoon 
into the milk and withdrawing it therefrom. This is termed ropy milk, 
and is more often met with in warm weather. It is undoubtedly produced 
as a result of bacterial action. 

Enzyme-forming Bacteria are not uncommonly developed in milk, 
causing various proteolytic changes, whereby the casein is partially trans- 
formed into peptones, caseoses, etc. 

Chromogenic Bacteria are the agencies that produce peculiar pigments 
in milk. Thus red milk is due to Bacillus erythrogenes; yellow milk to 
Bacillus xynxanthus; blue milk to Bacillus cyanagenes. The latter is 
quite common, appearing ordinarily in patches in the milk. 

CHEMICAL ANALYSIS OF MILK. 

Ordinarily, in ascertaining the nutritive value of milk, one determines 
its specific gravity, total solids, fat, protein, lactose, and ash. Occa- 
sionally it is thought desirable to make a distinction in the case of protein 
between the casein and the albumin. Rarely is it necessary to further 
subdivide the nitrogenous bodies in milk, unless in connection with a 
special study of the proteolytic changes which it undergoes. 

The total solids, fat, and ash are usually all determined directly, and, 
in the case of the lactose and the protein, a determination of either one 
may be directly made (whichever is most convenient), the other being 
calculated by difference. 

When foreign ingredients or adulterants are present in milk, special 
methods are employed to detect them. 

Preparation of the Sample. — In procuring a sample for analysis, the 
greatest care is necessary to insure a homogeneous sample. By far the 
best method in every case, where possible, is to pour the milk back and 
forth from one vessel to another (i.e., pour from the original container 



118 



FOOD INSPECTION AND ANALYSIS. 



mbm 



/ 



into an empty vessel and back at least once). Where this is impossible 
from the size of the container or for any other reason, the milk should 
be thoroughly mixed with a dipper. A " sampler," of which the Scovell 
sampling- tube (Fig. 43, A) is a, convenient form, also 
aids in securing a representative sample, and is invalu- 
able when it is desirable to secure a definite fraction of 
the whole for a composite sample. 

This instrument consists of a brass or copper tube 
made in two parts which telescope accurately together 
as shown in Fig. 43, A, the lower part being closed 
at the bottom, but provided with three or more lateral 
slits. The sampler, drawn out to its full length, is 
carefully inserted in the tank containing the milk and 
lowered to the bottom, after which the upper part is 
pressed down over the lower so as to close the slits, and 
the tube is then lifted out of the tank, containing a fairly 
representative sample of the milk. 

Samples may be preserved in condition suitable for 
determination of fat and solids for several days by add- 
ing to each quart i gram of potassium bichromate, 0.2 
gram of mercuric chloride mixed with a coal-tar color 
to show its poisonous nature, or i cc. of 40 % formalde- 
hyde. If other determinations are to be made, the 
analyst should make certain that the results on the 
rgm m, prescrvcd samples are the same as those on the fresh 
III ^a material. 

In all operations to which a milk sample is submitted 
during the process of analysis, it should invariably be 
poured into a clean empty vessel and back, or shaken, 
whenever it has been at rest for an appreciable time, 
in order to insure a homogeneous mixture. 

Determination of Specific Gravity. — This is most 
readily obtained with the aid of a hydrometer, accurately 
graduated within the limits of the widest possible variation in the specific 
gravity of milk. Hydrometers for special use with milk are known as 
lactometers, and are graduated variously. One of the most convenient 
forms of this instrument is the Quevenne lactometer, graduated from 15° 
to 40°, corresponding to specific gravity 1.015 to 1.040. This instrument, 
shown in Fig. 43, B, has a thermometer combined with it, the stem con- 



A B 

Fig. 43. 

A, Scovell Milk- 
Sampling Tube. 

B, Quevenne Lac 
tometer. 



MILK AND ITS PRODUCTS. 



119 



taining a double scale, on the lower part of which the specific gravity is 
read, while the temperature is read from the upper part. 

Another form of instrument is termed the New York Board of Health 
lactometer, which is not graduated to read the specific gravity directly, but 
has an arbitrary scale divided into 120 equal parts, the zero being equal 
to the specific gravity of water, while 100 corresponds to a specific gravity 
of 1.029. Deghuee * has devised a special form requiring only 4 ounces 
of milk. To convert readings on the New York Board of Health scale 
to Quevenne degrees they must be multiplied by .29. 

QUEVENNE LACTOMETER DEGREES CORRESPONDING TO NEW YORK 
BOARD OF HEALTH LACTOMETER DEGREES. 



Board of 


Quevenne 
Scale. 


Board of 


Quevenne 

Scale. 


Board of 


Quevenne 
Scale. 


Health 
Degrees. 


Health 
Degrees. 


Health 
Degrees. 


60 


17.4 


81 


23-5 


lOI 


29-3 


61 


17-7 


82 


23.8 


102 


29 


6 


62 


18.0 


83 


24.1 


103 


29 


9 


63- 


18.3 


84 


24.4 


104 


30 


2 


64 


18.6 


85 


24.6 


105 


30 


S 


65 


18.8 


86 


24.9 


106 


30 


7 


66 


19. 1 


87 


25.2 


107 


31 





67 


19.4 


88 


25-5 


108 


31 


3 


68 


19.7 


89 


25.8 


109 


31 


6 


69 


20.0 


90 


26.1 


no 


31 


9 


70 


20.3 


91 


26.4 


III 


32 


2 


71 


20.6 


92 


26.7 


112 


32 


5 


72 


20.9 


93 


27.0 


113 


32 


8 


73 


21.2 


94 


27-3 


114 


33 


I 


74 


21-5 


95 


27.6 


"5 


33 


4 


75 


21.7 


96 


27.8 


116 


33 


6 


76 


22.0 


97 


28.1 


117 


33 


9 


77 


22.3 


. 98 


28.4 


iiS 


34 


2 


78 


22.6 


99 


28.7 


119 


34 


5 


79 * 


22.9 


100 


29.0 


120 


34 


8 


80 


23.2 











. If extreme accuracy is desired, the Westphal balance or the pycnometer 
should be used for the determination of specific gravity. For ordinary 
cases, however, the lactometer, if carefully made, is sufficiently accurate. 

With any other form of lactometer than the Quevenne, a separate 
thermometer is necessary in order to determine the temperature, the 
common practice being to standardize all such instruments at 60° F. 
(15.6° C). 

Readings at temperatures other than 60° may be corrected to that 
temperature by the aid of the table on page 133. 

DETERMINATION OF TOTAL SOLIDS.— Dish Method.— For purposes 
of milk analysis, platinum dishes are by far the most desirable. These, 
if made for the purpose, should be of the shape shown in Fig. 51, measur- 



Jour. Ind. Eng. Chem., 3, 191 1, p. 405- 



120 



FOOD INSPECTION AND ANALYSIS. 



FOR CORRECTING THE SPECIFIC GRAVITY OF MILK ACCORDING TO 
TEMPERATURE (BY DR. PAUL VIETH). 



Degrees 

of 


Degrees of Thermometer (Fahrenheit). 


Lactom- 


































ster. 


45 


46 


47 


4« 


49 


so SI 


52 


53 


54 


55 


50 


57 


5« 


59 


60 


20. 




19.0 


19.0 


19. 1 


19. 1 


19.2 


19.2 19.3 


19.4 


19.4 


19-5 


19.6 19.7 


19.8 


19.9 


19.9 


— 


21. 






iQ.q 


20.0 


20.0 


20.1 


20.2 


20.2 20.3 


20.3 


20.4 


20.5 


20.6 20.7 


20.8 


20.9 


20.9 


— 


22. 






20.9 


21 .0 


21.0 


21. 1 


21.2 


21 .2 21 .3 


21-3 


21.4 


21-5 


21.6,21.7 


21.8 


21. 9 


21 .9 


— 


2S- 






21.9 


22.0 


22.0 


22.1 


22.2 


22.2 22.3 


22.3 


22.4 


22.5 


22.6'22.7 


22.8 


22.8 


22.9 


— 


24. 






22.9 


22.9 


23-0 


23.1 


23-2 


23.2 23.3 


23-3 


23-4 


23-5 


23-6;23.6 


23-7 


23.8 


23-9 


— 


2S. 






23.8 


23-9 


24.0 


24.0 


24.1 


24.1 24.2 


24-3 


24.4 


24-5 


24.6 


24-b 


24.7 


24.8 


24.9 


— 


2(5. 






24.8 


24-0 


24.9 


25.0 


25-1 


25-1 


25.2 


25.2 


25-3 


25-4 


25-5 


25.6 


25-7 


25.8 


25-9 


— 


27. 






2^.8 


2=^.9 


2S-Q 


26.0 


26.1 


26.1 


26.2 


26.2 


26.3 


26.4 


26.5 


26.6 


26.7 


26.8 


26.9 


— 


28. 






26.7 


26.8 


26.8 


26.9 


27.0 


27.0 


27.1 


27.2 


27-3 


27.4 


27-5 


27.6 


27-7 


27.8 


27.9 


— 


2Q. 






27.7 


27.8 


27.S 


27.9 


28.0 


28.0 


28.1 


28.2 


28.3 


28.4 


28.5 


28.6 


28.7 


28.8 


28.9 


— 


30. 






28.6 


28.7 


28.7 


28.8 


28.9 


29.0 


29.1 


29.1 


29.2 


29-3 


29.4 


29.6 


29-7 


29.8 


29.9 


— 


31- 






29-5 


29.6 


29.6 


29.7 


29.8 


29.9 


30.0 


30.1 


30.2 


30-3 


30-4 


30-5 


30.6 


30.8 


30-9 


— 


32. 






30-4 


30.5 


30-5 


30.6 


30-7 


30-9 


31.0 


31-1 


31.2 


31-3 


31-4 


31-5 


31.(3 


31-7 


31-9 


— 


.IV 







31-3 


31-4 


31-4 


31-5 


31.6 


31.8 


31-9 


32.0 


32.1 


32-3 


32-4 


32-5 


32.0 


32-7 


32-9 


— ■ 


34- 






32-2 


32.3 


32-3 


34-432-5 


32-7 


32-9 


33-0 


33-^ 


33-2 


33-3 


33-5 


33-6 


33-7 


33-9 


— 


35- 


... 




33-0 


33--^ 


33-2 


33-4 33-5 


33-b 


33-^ 


33-9 


34-0 


34-2 


34-3 


34-5 


34-6 


34-7 


34-9 







61 


62 


63 


64 


6s 


66 


67 


68 


69 


70 


71 


72 


73 


74 


75 


20. 




20.1 20.2 


20.2 


20.3 


20.4 


20.5 


20.6 


20.7 


20.9 


21.0 


21. 1 


21.2 


21-3 


21.5 


21.6 


21. 


. . . 






21. 1 21.2 


21.3 


21.4 


21-5 


21.6 


21.7 


21.8 


22.0 


22.1 


22.2 


22.3 


22.4 


22.5 


22.6 


22. 








22.1 22.2 


22.3 


22.4 


22.5 


22.6 


22.7 


22.8 


23.0 


23.1 


23.2 


23.3 


23.4 


23-5 


23-7 


23- 








23.1 23.2 


23-3 


23-4 


23-5 


23.6 


23.7 


23.8 


24.0 


24.1 


24.2 


24-3 


24.4 


24.6 


24-7 


24. 








24.1 24.2 


24-3 


24.4 


24-5 


24.6 


24.7 


24.9 


25-0 


25.1 


25.2 


25.3 


25-5 


25-6 


25-7 


2S- 








25-1,25-2 


25-3 


25-4 


25-5 


25.6 


25.7 


25-9 


26.0 26.1 


26.2 


26.4 


26.5 


26.6 


26.8 


26. 









26.I126.2 


26.3 


26.5 


26.6 


26.7 


26.8 


27.0 


27.l'27.2 


27.3 


27.4 


27-5 


27-7 


27.8 


27. 


. . . 






27.1 


27-3 


27-4 


27-5 


27.6 


27.7 


27.8 


28.0 


28.1 


28.2 


28.3 


28.4 


28.6 


28.7 


28.9 


28. 









28.1 


28.3 


28.4 


28.5 


28.6 


28.7 


28.8 


29.0 


29.1 


29.2 


29.4 


29-5 


29-7 


29.8 


29.9 


29. 









29.1 


29-3 


29.4 


29-5 


29.6 


29.8 


29.9 


30.1 


30.2 


30-3 


30-4 


30-5 


30.7 


30-9 


31-0 


30- 









30.1 


30-3 


30-4 


30-5 


30-7 


30.8 


30-9 


3I-I 


31.2 


3^-3 


31-5 


31.6 


31.8 


31-9 


32.1 


31- 









31.2 


3^-3 


31-4 


31-5 


31-7 


31.7 


31.8 


32.0 


32.2 


32.4 


32.5 


32-6 


32.8 


33-0 


33.1 


32. 









32.2 


32.3 


32-5 


32.6 


32.732.9 


33.0 


33.2 


33.333.4 


33-6 


33-7 


33-9 


34-0 


34.2 


33- 









33-2 


33-3 


33-5 


33.6 


33-833.9 


34.0 


34.2 


34.334.5 


34.6 


34-7 


34-9 


35-1 


35-2 


34- 








34-2 


34-3 


34.5 


34.6 


34.834.9 


35.0 


35-2 


35.3,35-5 


35.6 


35 -« 


36.0 


36.1 


36.3 


35- 


... 






35-2 


35-3 


35-5 


35. (^ 


35.8|35-9 


3^.1 


36.2 


36.4136.5 


36.7 


36.8 


37-0 


37.2 


37.3 



ing about 2f inches in diameter at the top, and 2^ inches in diameter 
at the bottom, having carefully rounded rather than square edges, and 
being ^ inch deep. The bottom is not perfectly flat, but slightly crowned 
outward. Such a dish will hold about 35 cc. 

For purposes of economy it is best to have these dishes spun out with 
a thick bottom, but with thin sides, not so thin, however, as to be too 
readily bent. 

If platinum dishes cannot be afforded, dishes of porcelain, glass, 
aluminum, nickel, or even tin may be used, but in all cases should be 
as thin as practicable. 

About 5 cc. of the thoroughly mixed sample of milk are carefully 



MILK AND ITS PRODUCTS. 121 

transferred by means of a pipette to a tared dish on the scale-pan, and its 
weight accurately determined. The dish with its contents is then trans- 
ferred to a water-bath, being placed over an opening preferably but little 
smaller than the diameter of the bottom of the dish, so that as large a 
surface as possible is in contact with the live steam of the bath. Here 
it is kept for at least two hours, after which the dish is wiped dry while 
still hot, transferred to a desiccator, cooled, and weighed.* 

Babcock Asbestos Method. f — Provide a hollow cylinder of perforated 
sheet metal, 60 mm. long and 20 mm. in diameter, closed 5 mm. from 
one end by a disk of the same material. The perforations should be 
about 0.7 mm. in diameter and about 0.7 mm. apart. Fill loosely with 
from 1.5 to 2.5 grams of freshly ignited, woolly asbestos, free from fine 
and brittle material, cool in a desiccator, and weigh. Introduce a 
weighed quantity of milk (between 3 and 5 grams), and dry in a water- 
oven to constant weight, which is usually reached after four hours' heating. 

Determination of Ash. — The platinum dish containing the milk 
residue, obtained in the determination of total solids by the dish method 
described above, is next placed upon a suitable support above a Bunsen 
flame (a platinum triangle or a ring stand is convenient for this), and 
the residue is ignited at a dull-red heat to a perfectly white ash, after 
which it is cooled and weighed. 

Determination of Fat.— Babcock Asbestos Method.— Extract the 
residue from the determination of water by the Babcock asbestos method 
with anhydrous ether in a continuous extraction apparatus, until all the 
fat is removed, which usually requires two hours. Evaporate the ether, 
dry the fat in the extraction flask at the temperature of boiling water, 
and weigh. The fat may also be determined by difference, drying the 
extracted cylinders at the temperature of boiling water. 

* It is a common practice to transfer the milk residue, after a preliminary drying on the 
water-bath, to an air-oven, kept at a temperature of from 100° to 105°, where it is dried to 
a constant weight; but after an experience in analyzing over 30,000 samples of milk, the 
author is prepared to state that in his opinion the results obtained by the above method of 
procedure, using the water-bath alone, are more satisfactory. It is impossible to keep a 
milk residue at a temperature above 100° for any length of time without its undergoing 
decomposition, especially as to its sugar content, as is shown by the darkening in color. A 
milk residue should be nearly pure white, a brownish color showing incipient decomposi- 
tion. Hence, by continued heating, especially at the temperature of 105°, the residue would 
continue to lose weight almost indefinitely. If it is thought best to give a final drjang in 
the air-oven, the time should be short and the temperature employed should not in any case 
exceed 100°. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 38, p. 100. 



122 FOOD INSPECTION AND ANALYSIS. 

The Adams Method. — For this method a strip of fat-free filter-paper 
about 2h inches wide and 22 inches long is rolled into a coil and held in 
place by a wire as shown in Fig. 44. Schleicher and Schiill furnish fat- 
free strips especially for this work, but it is very easy to prepare the strips 
and extract them with the Soxhlet apparatus. 

About 5 grams of milk are run into a beaker with a pipette, and the 
weight of the beaker and milk are determined. The coil is then intro- 
duced into the beaker, holding it by the wire in such a manner that as 
much as possible of the milk is absorbed by the paper. It is often possible 
to take up almost the last drop of the milk. By then weighing the beaker, 
the amount of milk absorbed by the coil is determined by 
difference, and the paper coil is hung up and dried, first 
in the air and then in the oven at a temperature not ex- 
ceeding 100°. Another method of charging the paper coil 
consists in suspending it by the wire and gradually de- 
livering upon it 5 cc. of the milk from a pipette, the dens- 
ity of the milk being known. 

The coil containing the dried residue is then transferred 
to the Soxhlet extraction apparatus (see p. 53) and sub- 
jected to continuous extraction with anhydrous ether for 
at least two hours, the receiving-flask being first accur- 
ately weighed. The tared flask with its contents is freed 
from all remaining ether, first on the water-bath and finally 
in the air-oven. It is then cooled and weighed, the in- 
Adams Milk- urease in weight representing the fat in the amount of 
fat Coil. milk absorbed by the coil. If there is any doubt about 

all the fat having been extracted at first, the process of extraction 
may be continued till there is no longer a gain in weight of the flask. 
Experience soon shows the length of time necessary for the complete 
extraction, which of course depends on the degree of heat employed, and 
the frequency with which the extracting-tube overflows. Two hours is 
ample for most cases, in which the conditions are such that the ether 
siphons over from the extraction-tube ten times per hour. 

FAT Methods Based on Centrifugal Separation.— These 

methods are the most practicable for commercial work and for use by 
the public analyst, since they are much more rapid, and, if carefully 
carried out, practically as accurate as the Adams method. They all 
depend upon the use of a centrifuge usually having hinged pockets 
in which are carried graduated bottles, into each of which a measured 




MILK AND ITS PRODUCTS. 



123 



quantity of milk is introduced. The milk is then subjected to the action 
of a suitable reagent, which dissolves the casein and liberates the fat in 
a pure state, after which, by whirling at a high speed, the pockets are 
thrown out horizontally and the milk fat driven into the neck of each 
bottle, where the amount is directly read. 

The Babcock Test, although devised originally for the use of creameries 
and dairymen, is now extensively employed for fat determination in the 
laboratory. Leach found that the results by the Babcock test and the 
Adams method, obtained from time to time during ten years, agreed 
within narrow limits. The following ifigures show the results of such 
comparative determinations made in duplicate on three samples of milk, 
viz., a pure whole milk, (i) and (2) ; a watered milk, (3) and (4), and a milk 
centrifugally skimmed, (5) and (6). 



COMPARATIVE FAT DETERMINATION BY ADAMS-SOXHLET AND BY 
BABCOCK PROCESSES. 





Per Cent of 

Fat by the 

Adams-Soxh- 

let Process. 


Per Cent of 
Fat by the 
Babcock • 
Process. 


A whole milk . . . (i) 


4.27 
4.28 
2.70 
2.74 
0.16 
0.14 


4-30 
4-35 
2.70 
2.80 
oiS 
015 


(2) 


A watered milk (3) 


(4) 


A skimmed milk (5) 


(6) 





Equally satisfactory results were obtained by Winton, using the Bab- 
cock asbestos method for comparison. 

The Centrifuge. — Various styles of centrifuge, carrying from 2 to 
40 bottles, are in use for this process. 

Two forms of hand machine are shown in Fig. 45, one {D), for two 
bottles, arranged to screw on the edge of a table, the other for twelve bottles 
inclosed in a cast-iron case. 

The number of revolutions of the revolving frame for each turn 
of the crank and the number of turns per minute necessary to secure 
the requisite number of revolutions of the frame should be determined 
once for all for each machine and the latter adhered to in making all 
tests. 



124 



FOOD INSPECTION AND ANALYSIS. 








Fig. 45. — Apparatus for Babcock Test. 
A, Burrell's electric centrifun;e; B, Burrell's steam turbine centrifuge; C and D, Burrell's 
hand centrifuges; E, milk bottle; F, Wagner's skim-milk bottle; G, Swedish or combined 
acid bottle. 



MILK AND ITS PRODUCTS. 125 

The steam turbine machines (Fig. 45, B) are simple in construction 
and the steam serves to keep the bottles warm as well as to furnish power. 
The steam impinges against a series of paddles on the outer periphery of 
the revolving frame, driving it like a horizontal water-wheel. A reverse 
steam jet, steam gauge, and hot-water tank for filling the bottles are also 
provided. 

Fig. 45, A shows an electric machine for 24 to 36 bottles. Laboratory 
centrifuges are also provided with frames for Babcock bottles. 

Glassware. — The ordinary test bottle for milk is shown in Fig. 45, E. 
It has graduations corresponding to from o to 10% of fat, using 17.6 cc. 
of milk. One of various forms of skim milk bottle is also shown (F), 
The graduated tube has a capacity corresponding to only 0.25% for its 
entire length, hence the need of a second tube of larger bore for filling. 

The pipettes are graduated to hold 17.6 cc, which for average milk 
weighs 18 grams. The lower tube should be of such a size as to enter the 
nerk of the test bottle. 

A 17.5 cc. cylinder is provided for measuring the acid, but where 
considerable numbers of tests are made some special measuring device 
is desirable. Fig. 45, G shows a combined acid bottle and pipette, the 
latter being filled by tipping up the bottle. 

Manipulation. — Pipette 17.6 cc. (corresponding to 18 grams) of the 
milk into the test bottle and add 17.5 cc. of commercial sulphuric acid. 
(sp.gr. 1. 82-1. 84), Mix thoroughly by a vigorous rotatory movement 
holding the neck of the bottle between the fingers and at a slight angle 
away from the body. The lumps of curd which at first form disappear 
upon shaking; much heat is developed during the mixing and the color 
changes to deep brown. 

Place the test bottles in the pockets of the centrifuge (symmetrically 
arranged to keep the revolving frame in balance) and whirl at the rate of 800 
to 1000 revolutions per minute, according to the diameter of the frame, for 
5 minutes. Stop the machine, fill each bottle up to the neck with boiling 
water and whirl for two minutes longer. Add boiling water up to near 
the top of the graduation and whirl finally for two minutes. 

Remove the bottles from the machine and take the readings of the 
bottom and the very top of the fat column, the difference being the per cent 
of fat. If desired, the percentage may be obtained directly by means of 
calipers. To avoid danger of cooling it is well to immerse the bottles nearly 
to the top of the neck in water at 60° C, removing one at a time for 
reading. 



126 rOOD INSPECTION AND ANALYSIS. 

The Werner-Schmidt Method.— Ten cc. of milk are introduced by 
means of a pipette into a large test-tube of 50 cc. capacity, and 10 cc. of 
concentrated hydrochloric acid are added. The mixture is shaken and 
heated till the liquid turns a dark brown, either by direct boiling for a 
minute or two, or by immersing the tube in boihng water for from five to 
ten minutes. The tube is then cooled by im- 
mersion in cold water, and 30 cc. of washed ether 
is added. The tube is closed by a cork provided 
with tubes similar to a wash-bottle, the larger 
tube being adapted to slide up and down in the 
cork, and preferably being turned up slightly at 
the bottom. The contents of the tube are 
shaken, the ether layer allowed to separate, and 
the sliding-tube arranged so that it terminates 
slightly above the junction of the two layers. 
The ether is then blown out into a weighed 
flask. A second and a third portion of ether 
of 10 cc. each are successively shaken with the 
acid Hquid and added to the contents of the 
weighed flask, from which the ether is subse- 
quently evaporated and the weight of the fat 

easily obtained. FiG.46.^TheWerncr-Schm;dt 

. 1 -n • 1 • ^^^ Apparatus. 

Instead of measurmg the milk mto the testmg- 
tube, a known weight of milk may be operated on. A sour milk may be 
readily tested in this way, provided it is previously well mixed. 

Determination of Fat by the Wollny Milk-fat Refractometer.* — This 
instrument presents the same appearance as the butyro-refractometer, 
Fig. 38, with an arbitraiy scale reading from o to 100, the equivalent 
readings in indices of refraction of the Wollny instrument varying from 
1.3332 to 1.4220. Exactly 30 cc. of the milk to be tested are measured 
into the stoppered flask A, Fig. 47. This may be done by the use of 
the automatic pipette, which holds exactly 7I cc, removing four pipettes 
full of the milk. 5 is a numbered tin samphng-tube in which the milk 
sample is kept for convenience, and into which the automatic pipette 
readily fits. Having measured 30 cc. of the milk into the flask A, 12 
drops of a solution of 70 grams potassium bichromate and 312.5 cc. of 
stronger ammonia in one liter of water may be added as a preservative. 




* Milch Zeit., 1900, pp. 50-53. 



MILK AND ITS PRODUCTS. 



127 



if the sample is to be kept for some time before finishing the test. Twelve 
drops of glacial acetic acid are added to curdle the milk. The flask is 
then corked and shaken for one to two minutes in a mechanical shaker, 
after which 3 cc. of a standard alkaline solution are added, and the flask 
corked and shaken for ten minutes in the mechanical shaker, the tempera- 
ture being kept at i7.5°C. The standard alkaline solution is prepared 




Fig. 47. — Accessories for Carrying Out the Wo liny Milk-fat Process. 

by dissolving 800 cc. of potassium hydroxide in a liter of water, adding 
600 cc. of glycerin and 200 grams pulverized copper hydrate, the mixture 
being allowed to stand for several days before using, shaking at intervals. 
Finally 6 cc. of water-saturated ether are added to the mixture in the 
flask, using for convenience the automatic pipette fitted in the corked 
bottle as shown. The flask is again shaken for fifteen minutes in the 
mechanical shaker, and whirled for three minutes in the centrifuge, after 
which a few drops of the ether solution are transferred to the refractometer, 
and the reading taken. The percentage of fat is obtained by means of 
the following table: 



128 



FOOD INSPECTION AND ANALYSIS. 



PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE 
WOLLNY REFRACTOMETER. 



Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


20. o 




24.5 


0.41 


29.0 


0.87 


33-5 


1-34 


38.0 


1-85 


42.5 


2.41 


I 




6 


0.42 


I 


0.88 


6 


I-3S 


I 


1.87 


6 


2-43 


2 




7 


0.43 


2 


0.89 


7 


1.36 


2 


1.88 


7 


2-44 


3 




8 


0.44 


3 


0.90 


8 


1-37 


' 3 


1.89 


8 


2.46 


4 




9 


0-45 


4 


0.91 


9 


1.38 


4 


1.90 


9 


2.47 


5 




25.0 


0.46 


5 


0.92 


34-0 


1-39 


5 


1. 91 


43-0 


2-49 


6 


0.00 


I 


0.47 


6 


0-93 


I 


1.40 


6 


1.92 


I 


2.50 


7 


O.OI 


2 


0.48 


7 


0.94 


2 


1.42 


7 


1-93 


2 


2.51 


8 


0.02 


3 


0.49 


8 


0-95 


3 


1-43 


8 


1.94 


3 


2.52 


9 


0.03 


4 


0.50 


9 


0.96 


4 


1-44 


9 


1-95 


4 


2-54 


21.0 


0.04 


5 


0-51 


30.0 


0.97 


5 


I-4S 


39-0 


1.96 


5 


2-55 


I 


0.05 


6 


0.52 


I 


0.98 


6 


1.46 


I 


1.98 


6 


2.56 


2 


0.06 


7 


0-53 


2 


0.99 


7 


1-47 


2 


1-99 


7 


2.58 


3 


0.08 


8 


0.54 


3 


1. 00 


8 


1.48 


3 


2.00 


8 


2.60 


4 


0.09 


9 


0-S5 


4 


1. 01 


9 


1-49 


4 


2.02 


9 


2.61 


5 


O.IO 


26.0 


0-57 


5 


1.02 


35-0 


1-50 


5 


2.03 


44.0 


2.63 


6 


O.II 


I 


0.58 


6 


1.03 


I 


i-Si 


6 


2.04 


I 


2.64 


7 


0.12 


2 


0-59 


7 


1.04 


2 


1-52 


7 


2.05 


2 


2.65 


8 


0.13 


3 


0.60 


8 


1.05 


3 


1-54 


8 


2.07 


3 


2.67 


9 


0.14 


4 


0.61 


9 


1.06 


4 


1-55 


9 


2.08 


4 


2.68 


32.0 


0-15 


5 


0.62 


31.0 


1.07 


5 


1.56 


40.0 


2.09 


5 


2.70 


I 


0.16 


6 


0.63 


I 


1.08 


6 


1-57 


I 


2.10 


6 


2.71 


2 


0.17 


7 


0.64 


2 


1.09 


7 


1-58 


2 


2.12 


7 


2.72 


3 


0.18 


8 


0.65 


3 


l.IO 


8 


1-59 


3 


2.13 


8 


2.74 


4 


0.19 


9 


0.66 


4 


I. II 


9 


1.60 


4 


2.14 


9 


2-75 


5 


0.20 


27.0 


0.67 


5 


I. 12 


36.0 


1-61 


5 


2-15 


45-0 


2.77 


6 


0.21 


I 


0.68 


6 


I-I3 


I 


1.62 


6 


2.16 


I 


2.78 


7 


0.22 


2 


0.69 


7 


I. 14 


2 


1.64 


7 


2.18 


2 


2-79 


8 


0.23 


3 


0.70 


8 


i-iS 


3 


1.65 


8 


2.20 


3 


2.80 


9 


0.24 


4 


0.71 


9 


I. 16 


4 


1.66 


9 


2.21 


4 


2.82 


33.0 


0.25 


5 


0.72 


32.0 


I. 17 


5 


1.67 


41.0 


2.23 


5 


2.84 


I 


0.26 


6 


0-73 


I 


I. 18 


6 


1.68 


I 


2.24 


6 


2-85 


2 


0.27 


7 


0.74 


2 


I. 19 


7 


1.69 


2 


2-25 


7 


2.87 


3 


0.28 


8 


0-7S 


3 


1.20 


8 


1.70 


3 


2.26 


8 


2.88 


4 


0.29 


9 


0.76 


4 


1.22 


9 


1. 71 


4 


2.27 


9 


2.89 


5 


0.30 


28.0 


0.77 


5 


1-23 


37-0 


1.72 


5 


2.28 


46.0 


2.90 


6 


0.31 


I 


0.78 


6 


1.24 


I 


1-73 


6 


2.30 


I 


2.92 


7 


0.32 


2 


0.79 


7 


1.25 


2 


1-75 


7 


2-32 


2 


2-93 


8 


0-33 


3 


0.80 


8 


1.26 


3 


1.76 


8 


2-33 


3 


2-94 


9 


0-34 


4 


0.81 


9 


1.27 


4 


1.78 


9 


2.34 


4 


2.96 


24.0 


0.36 


5 


0.82 


33-0 


1.28 


5 


1-79 


42.0 


2-35 


5 


2.98 


I 


0-37 


6 


0.83 


I 


1.29 


6 


1.80 


I 


2-37 


6 


3.00 


2 


0.38 


7 


0.84 


2 


1.30 


7 


1. 81 


2 


2.38 


7 


3.01 


3 


0-39 


8 


0.85 


3 


I-3I 


8 


1.82 


3 


2-39 


8 


3.02 


4 


0.40 


9 


0.86 


4 


1.32 


9 


1.84 


4 


2.40 


9 


3-03 


5 


0.41 


29.0 


0.87 


5 


1-34 


38.0 


1.85 


5 


2.41 


47.0 


3-05 



MILK AND ITS PRODUCTS 



129 



PERCENTAGES OF FAT CORRESPONDING TO SCALE READINGS ON THE 
WOLLNY REFRACTOMETER —{Continued). 



Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Scale 


Per 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


Read- 


Cent 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


ing. 


Fat. 


47.0 


3-05 


50-5 


3-59 


S4-0 


4.18 


57-5 


4-78 


61.0 


5-44 


64-5 


6.14 


I 


3.06 


6 


3.60 


I 


4.20 


6 


4.80 


I 


5-46 


6 


6.16 


2 


3.08 


7 


3-61 


2 


4.22 


7 


4.82 


2 


5-48 


7 


6.18 


3 


3.10 


8 


3-63 


3 


4-23 


8 


4-84 


3 


5-50 


8 


6.20 


4 


3.12 


9 


3-64 


4 


4-25 


9 


4.86 


4 


5-52 


9 


6.22 


5 


3-14 


51-0 


3.66 


5 


4.26 


58.0 


4.88 


5 


5-54 


65.0 


6.24 


6 


3-15 


I 


3-67 


6 


4.28 


I 


4.90 


6 


5-56 


I 


6.27 


7 


3-16 


2 


3-68 


7 


4-29 


2 


4-92 


7 


5-58 


2 


6.29 


8 


3-17 


3 


3-70 


8 


4-31 


3 


4-94 


8 


5.60 


3 


6.31 


9 


3-18 


4 


3-72 


9 


4-33 


4 


4-95 


9 


5.61 


4 


6.34 


48.0 


3.20 


5 


3-74 


55-0 


4-35 


5 


4-97 


62.0 


5-63 


5 


6.36 


I 


3-21 


6 


3-76 


I 


4-37 


6 


4-98 


I 


5-65 


6 


6.38 


2 


3-23 


7 


3-78 


2 


4.38 


7 


5.00 


2 


5-66 


7 


6.40 


3 


3-25 


8 


3.80 


3 


4.40 


8 


5.02 


3 


5-68 


8 


6.42 


4 


3-27 


9 


3-82 


4 


4-42 


9 


5-04 


4 


5-70 


9 


6-44 


5 


3-28 


52.0 


3-84 


5 


4-43 


59-0 


5.06 


5 


S-72 


66.0 


6.46 


6 


3-30 


I 


3-85 


6 


4-44 


I 


5.08 


6 


5-74 






7 


3-32 


2 


3-87 


7 


4.46 


2 


5-10 


7 


5-76 






8 


3-33 


3 


3-89 


8 


4-48 


3 


5-II 


8 


5-78 






9 


3-34 


4 


3-90 


9 


4-49 


4 


5-13 


9 


5-80 






49 


3.36 


5 


3-92 


56.0 


4-51 


5 


5-iS 


, 63.0 

j 


5-82 






I 


3.38 


6 


3-93 


I 


4-53 


6 


S-17 


j I 


5-84 






2 


3-40 


7 


3-95 


2 


4-55 


7 


5-19 


1 2 


5-86 






3 


3-42 


8 


3-97 


3 


4-57 


8 


5.20 


3 


5-88 






4 


3-43 


9 


3-99 


4 


4-59 


9 


5-22 


4 


5-90 






5 


3-44 


53-0 


4.01 


5 


4.60 


60.0 


5-24 


5 


5-92 






6 


3-45 


I 


4-03 


6 


4.61 


I 


5-26 


6 


5-94 






7 


3-46 


2 


4.04 


7 


4-63 


2 


5-28 


7 


5-96 






8 


3-48 


3 


4.06 


8 


4-65 


3 


5-30 


8 


5-98 






9 


3-50 


4 


4.07 


9 


4.67 


4 


5-32 


9 


6.00 






5©.o 


3-51 


5 


4.09 


57-0 


4.69 


5 


5-34 


64.0 


6.02 






I 


3-53 


6 


4.10 


I 


4.71 


6 


S-36 


I 


6.04 






2 


3-55 


7 


4.12 


2 


4-73 


7 


5-38 


2 


6.07 






3 


3-56 


8 


4.14 


3 


4-75 


8 


5-40 


3 


6.09 






4 


3-57 


9 


4.16 


4 


4.76 


9 


5-42 


4 


6.12 






5 


3-59 


54-0 


4.18 


5 


4.78 


61.0 


5-44 


5 


6.14 







The following table is of use for those who wish to employ the 
Wollny meihod, but have the Abbe refractometer instead of the milk-fa*^ 
refractometer. 



130 



FOOD INSPECTION AND ANALYSIS. 



INDICES OF REFRACTION (np) CORRESPONDING TO SCALE READINGS OP 
THE WOLLNY MILK-FAT REFRACTOMETER. 



Refrac- 
tive 


Fourth Decimal of tij). 


Index, 






















"D- 





1 


2 


3 


4 


5 


6 


7 


8 


9 










Scale Readings. 










1-333 
1-334 






0.0 


0.1 


0. 2 


0-3 
1.2 


0.4 
1-3 


0.5 
1-4 


0-5 
1-5 


0.6 


0.7 


' ' 0.8 ' 


0.9 


I.O 


I.I 


1.6 


1-335 


1-7 


1.8 


1.9 


2.0 


2.1 


2.1 


2.2 


2-3 


2.4 


2-5 


1-336 


2.8 


2-7 


2.8 


2-9 


3-0 


3-1 


3-2 


3-3 


3-4 


3-5 


1-337 


3-6 


3-7 


3-7 


3-8 


3-9 


4-0 


4-1 


4-2 


4-3 


4-4 


1-338 


4-5 


4-6 


4-7 


4-8 


4-9 


5-0 


5-1 


5-2 


5-3 


5-4 


1-339 


5-5 


5-6 


5-7 


5-8 


5-9 


6.0 


6.1 


6.2 


6.3 


6.4 


1.340 


6-5 


6.6 


6-7 


6.8 


6.9 


6.9 


7-0 


7-1 


7-2 


7-3 


I -341 


7-4 


7-5 


7-6 


7-7 


7-8 


7-9 


8.0 


8.1 


8.2 


8.3 


1-342 


8.4 


8.5 


8.6 


8.7 


8.8 


8.9 


9.0 


9.1 


9.2 


9-3 


1-343 


9-4 


9-5 


9.6 


9-7 


9.8 


9-9 


10. 


10. 1 


10.2 


10.3 


1-344 


10.4 


10.5 


10.6 


10.7 


10.8 


10.9 


II. 


II. I 


II. 2 


11-3 


1-345 


II. 4 


11-5 


"-5 


II. 6 


II. 7 


II. 8 


II. 9 


12.0 


12. 1 


12.2 


1-346 


12.3 


12.4 


12.5 


12.6 


12.7 


12.8 


12.9 


13.0 


13-1 


13.2 


1-347 


13-3 


13-4 


13-5 


13.6 


13-7 


13-8 


13-9 


14.0 


14. 1 


14.2 


1.348 


14-3 


14.4 


14-5 


14.6 


14-7 


14.8 


14.9 


15-0 


15-1 


15.2 


1-349 


15-3 


15-4 


15-5 


15-6 


15-7 


15-8 


15-9 


16.0 


16. 1 


16.2 


1-35° 


16.3 


16.4 


16.S 


16.6 


16.7 


16.8 


16.9 


17.0 


17. 1 


17.2 


1-351 


17-3 


17-4 


17-S 


17.6 


17.7 


17.8 


17.9 


18.0 


18. 1 


18.2 


1-352 


18.3 


18.4 


18.5 


18.6 


18.7 


18.8 


18.9 


19.0 


19. 1 


19.2 


1-353 


19-3 


19.4 


19-5 


19.6 


19.7 


19.8 


19.9 


20.0 


20.1 


20.2 


1-354 


20.3 


20.4 


20.5 


20.6 


20.7 


20.8 


20.9 


21.0 


21. 1 


21.2 


1-355 


21-3 


21.4 


21-5 


21.6 


21.7 


21.8 


21.9 


22.0 


22.1 


22.2 


1-356 


22.3 


22.4 


22.5 


22.6 


22.7 


22.8 


22.9 


23.0 


23.1 


23.2 


1-357 


23-3 


23-4 


23-5 


23.6 


23-7 


23-8 


23-9 


24.0 


24.1 


24.2 


1-358 


24-3 


24-4 


24-5 


24.6 


24-7 


24.8 


24.9 


25.0 


25-1 


25.2 


1-359 


25-3 


25-4 


25-5 


25.6 


25-7 


25-8 


25-9 


26.0 


26.1 


26.2 


1.360 


26.3 


26.4 


26.5 


26.6 


26.7 


26.8 


26.9 


27.0 


27.1 


27.3 


1-361 


27-4 


27-5 


27.6 


27.7 


27.8 


27.9 


28.0 


28.1 


28.2 


28.3 


1.362 


28.4 


28.5 


28.6 


28.7 


28.8 


28.9 


29.0 


29.1 


29.2 


29-3 


1-363 


29-4 


29-5 


29.6 


29.7 


29.8 


29.9 


30.0 


30.1 


30.2 


30-3 


1.364 


30-4 


30-5 


30.6 


30-7 


30.8 


31.0 


31-1 


31.2 


3^-3 


31-4 


1-365 


31-5 


31-6 


31-7 


31-8 


31-9 


32.0 


32.1 


32.2 


32-3 


32-4 


1.366 


32.5 


32.7 


32.8 


32-9 


33-0 


33-1 


33-- 


33-3 


33-4 


33-5 


1-367 


33-6 


33-7 


33-8 


33-9 


34-0 


34-2 


34-3 


34-4 


34-5 


34-6 


1.368 


34-7 


34-8 


34-9 


35-0 


35-1 


35-2 


35-3 


35-4 


35-5 


35-6 


1.369 


35-7 


35-8 


36.0 


36.1 


36.2 


36-3 


36.4 


36-5 


36-6 


36.7 


1-370 


36.8 


36-9 


37-0 


37-1 


37-2 


37-3 


37-4 


37-6 


37-7 


37.8 


1-371 


37-9 


38.0 


38.1 


38-2 


38-3 


38-4 


38.5 


38.6 


38-7 


38.8 


1-372 


38-9 


39-0 


39-2 


39-3 


39-4 


39-5 


39-6 


39-7 


39-8 


39-9 


1-373 


40.0 


40.1 


40.2 


40.3- 


40.4 


40.5 


40.7 


40.8 


40.9 


41.0 


1-374 


41. 1 


41.2 


41-3 


41.4 


41-5 


41.6 


41-8 


41.9 


42.0 


42.1 


'•375 


42.2 


42.3 


42.4 


42.5 


42.6 


42.7 


42.8 


42.9 


43-0 


43-1 


1-376 


43-2 


43-3 


43-4 


43-6 


43-7 


43-8 


43-9 


44.0 


44-1 


44-2 


1-377 


44-3 


44-4 


44-6 


44-7 


44-8 


44-9 


45-0 


45-1 


45-2 


45-3 


1-378 


45-4 


45-6 


45-7 


45-8 


45-9 


46.0 


46.1 


46.2 


46.3 


46.4 


1-379 


46.6 


46.7 


46.8 


46.9 


47.0 


47-1 


47-2 


47-3 


47-4 


47.6 



MILK AND ITS PRODUCTS. 



131 



INDICES OF REFRACTION (no) CORRESPONDING TO SCALE READINGS OI 
THE WOLLNY MILK-FAT REFRACTOMETER— (Continued). 



Refrac- 








Fourth Decimal of "r 


• 








tive 
Index, 

























1 


2 


3 


4 


5 


6 


•7 


8 


9 












1 
Scale Readings. 










1.380 


47-7 


47-8 


47-9 


48.0 


48.1 


48.2 


48.3 


48.4 


48.6 


48.7 


I.381 


48.8 


48.9 


49.0 


49-1 


49-2 


49-3 


49.4 


49-6 


49-7 


49-8 


1.382 


49-9 


50.0 


50-1 


50.2 


50-3 


50.4 


50.6 


50-7 


50.8 


50-9 


1-383 


51.0 


51-1 


51.2 


51-3 


51-4 


51.6 


51-7 


51-8 


51-9 


52.0 


1.384 


52-1 


52.2 


52-3 


52.4 


52.6 


52-7 


52.8 


52-9 


53-0 


53-1 


1-385 


53-2 


53-3 


53-4 


53-6 


53-7 


53-8 


53-9 


54-0 


54-1 


54-2 


1.386 


54-3 


54-4 


54-6 


54-7 


54-8 


54-9 


55-0 


55-1 


55-2 


55-3 


1-387 


55-4 


55-6 


55-7 


55-8 


55-9 


56.0 


56-1 


56.2 


56.3 


56.5 


1.388 


56.6 


56-7 


56.8 


56.9 


57-1 


57-2 


57-3 


57-4 


57-6 


57-7 


1.389 


57-8 


57-9 


58.0 


58.1 


58.2 


58-3 


58-4 


58.6 


58-7 


58.8 


1.390 


58.9 


59-0 


59-1 


59-2 


59-4 


59-5 


59-6 


59-8 


59-9 


60.0 


I-391 


60.1 


60.2 


60.3 


60.4 


60.6 


60.7 


60.8 


60.9 


61.0 


61.1 


1.392 


61.3 


61.4 


61-5 


61.6 


61.8 


61.9 


62.0 


62.1 


62.2 


62.3 


1-393 


62.4 


62.6 


62.7 


62.8 


62.9 


63.0 


63-2 


63-3 


63-4 


63-5 


1-394 


63.6 


63.8 


63-9 


64.0 


64.1 


64.2 


64-4 


64-5 


64.6 


64-7 


1-395 


64.8 


65.0 


65.1 


65-2 


65-3 


65-4 


6c;. 6 


65-7 


65.8 


65-9 


1.396 


66.0 


66.2 


66.3 


66.4 


66.5 


66.6 


66.8 


66.9 


67.0 


67.1 


1-397 


67.2 


67.4 


67-5 


67.6 


67-7 


67.8 


67-9 


68.1 


68.2 


68.3 


1.398 


68.4 


68.6 


68.7 


68.8 


68.9- 


69.0 


69.1 


69-3 


69-4 


69-5 


1-399 


69.6 


69.8 


69.9 


70.0 


70.1 


70.2 


70.4 


70-5 


70.6 


70.8 


1.400 


70.9 


71.0 


71.1 


71.2 


71.4 


71-5 


71.6 


71.8 


71.9 


72.0 


1. 401 


72.1 


72.2 


72.4 


72-5 


72.6 


72.8 


72-9 


73-0 


73-1 


73-2 


1.402 


73-4 


73-5 


73-6 


73-8 


73-9 


74.0 


74-1 


74-2 


74-4 


74-5 


1.403 


74-6 


74-8 


74-9 


75-0 


75-1 


75-2 


75-4 


75-5 


75-6 


75-8 


1.404 


75-9 


76.0 


76.1 


76.2 


76.4 


76-5 


76.6 


76.8 


76-9 


77.0 


1-405 


77-1 


77-2 


77-4 


77-5 


77-7 


77-8 


77-9 


78.1 


78.2 


78.3 


1.406 


78.5 


78.6 


78.7 


78.8 


79.0 


79-1 


79-2 


79-4 


79-5 


79-6 


1.407 


79-8 


79-9 


80.0 


80.1 


80.2 


80.4 


80.5 


80.6 


80.8 


80.9 


1.408 


81.0 


81. 1 


81.2 


81.4 


81. 5 


81.6 


81.7 


81.9 


82.0 


82.1 


1.409 


82.3 


82.4 


82.5 


82.6 


82.8 


82.9 


83.0 


83.2 


83-3 


83-4 


1. 410 


83.6 


83-7 


83.8 


84.0 


84.1 


84.2 


84-4 


84-5 


84.6 


84.8 


1. 411 


84.9 


8s-o 


8^.2 


85-3 


85-4 


85-5 


85.6 


85-7 


85-9 


86.1 


1. 412 


86.2 


86.3 


86.5 


86.6 


86.7 


86.9 


87.0 


87.1 


87-3 


87.4 


1-413 


87-5 


87-7 


87.8 


87-9 


88.1 


88.2 


88.3 


88.=; 


88.6 


88.7 


1. 414 


88.9 


89.0 


89.1 


89-3 


89.4 


89.6 


89.7 


89.9 


90.0 


90.1 


I -415 


90.2 


90.4 


90-5 


90.6 


90.8 


90.9 


91.0 


91.2 


91-3 


91-5 


1. 416 


91.6 


91.7 


91.9 


92.0 


92.1 


92-3 


92-4 


92-5 


92-7 


92.8 


1. 417 


92-9 


93-1 


93-2 


93-3 


93-5 


93-6 


93-8 


93-9 


94.0 


94-2 


1.418 


94-3 


94-4 


94-6 


94-7 


94-8 


95 -0 


95-1 


95-3 


95-4 


95-6 


1. 419 


95-7 


95-8 


96.0 


96.1 


96.3 


96-4 


96.6 


96-7 


96.8 


97.0 


1.420 


97.1 


97-3 


97-4 


97-6 


97-7 


97-8 


98.0 


98.1 


98-3 


98-4 


1.421 


98-5 


98.7 


98.8 


99.0 


99-1 


99-3 


99-4 


99-5 


99-7 


99-9 


1.422 


100. 





















132 FOOD INSPECTION AND ANALYSIS. 

Determination of Proteins. — For determination of the total nitro- 
gen in milk, 5 cc. are measured direct into a Kjeldahl digestion-flask, 
or a known weight from a weighing-bottle may be used, and the regular 
Gunning method is employed as described on page 69, proceeding with 
the digestion at once without evaporation. 

The total nitrogen, multipHed by 6.38, gives the total proteins. By 
many the old factor of 6.25 is still employed, but in view of the fact that 
both casein and albumin have been found to contain 15.7% of nitrogen, 
there would seem to be the best reasons for employing 6.38 as a factor 
100 



15-7/ 
Ritthausen's Method. — ^Ten grams of milk are measured into a beaker 

and diluted with water to about 100 cc. Five cc. of a solution of copper 
sulphate (strength of Fehhng's copper solution, 34.64 grams CuSO^ in 500 cc. 
of water) are added and the mixture stirred. A solution of sodium hydrox- 
ide (25 grams to the liter) is added cautiously a little at a time, till the 
liquid is nearly, but not quite neutral, avoiding an excess of alkali, as 
this would prevent the complete precipitation of the proteins. Allow the 
precipitate to settle, and pour off the supernatant Hquid through a weighed 
fiker, previously dried at 130° C. Wash a number of times by decantation, 
and transfer the precipitate to the filter, being careful to remove the por- 
tions adhering to the sides of the beaker with a rubber-tipped rod. Wash 
thoroughly with water, and drain dry, after which the precipitate is washed 
with strong alcohol, dried, extracted with ether, preferably in a Soxhlet 
extractor, and then transferred on the filter to the oven, dried at 130° C, 
and weighed. The filter and precipitate are then burnt to an asii in a 
porcelain crucible, and the weight of the residue subtracted from the first 
weight gives that of the proteins. 

Richmond * recommends modifying this process to the extent of 
neutralizing the milk, using phenolphthalein as an indicator, before adding 
the copper sulphate solution, and using only 2.5 cc. of the latter. 

Determination of Casein.— Faw Slyke Method.-\— Ten grams of the 
milk sample are placed in a beaker, and made up with water to about 
100 cc. at 40° to 42° C. One and one-half cc. of a 10% solution (by weight) 
of acetic acid are added, the mixture stirred, warmed to the above tem- 
perature, and allowed to stand for from three to five minutes, till a floc- 

* Dairy Chemistry, London, 1914, p. 127. 

t U. S. Dept. of Agric, Div. of Chem., Bui. 43, p. 189; Bui. 51, p. 108. 



MILK AND ITS PRODUCTS. 133 

culent precipitate separates, leaving a clear supernatant liquid. Decant 
upon a filter, wash with cold water two or three times by decantation, 
and finally transfer the whole of the precipitate to the filter, and, after 
filtering, wash two or three times. The filtrate should be clear or nearly 
so. If not, it can generally be made so by repeated filtrations, and the 
washing done afterwards. The filter containing the washed precipitate 
is transferred to the Kjeldahl digestion-flask and the nitrogen obtained 
by the Gunning process. Nx 6.38 = casein. 

Determination of Albumin. — Van Siyke Method. — To the filtrate from 
the direct determination of casein by the acetic acid method as described 
in the preceding section, exactly neutralized with sodium hydroxide, 
0.3 cc. of a 10% solution of acetic acid is added, and the mixture is boiled 
till the albumin is completely precipitated. The precipitate is collected 
on a filter and washed, the nitrogen being determined in the precipitate, 
and the factor 6.38 used in calculating the albumin therefrom. 

Leffman and Beam Modification of the Sebelien Method.^ — Owing to 
the tedious processes of washing and filtering incidental to the above 
method for determining casein, the following is suggested. Mix 10 cc. of 
the milk with saturated magnesium sulphate solution, and saturate the 
mixture with the powdered salt. Make up to 100 cc. with the same solu- 
tion, mix, and allow the precipitate to settle, leaving a clear, supernatant 
layer. Withdraw as much as possible of the clear portion by a pipette 
and filter through a dry filter. Precipitate the albumin in an aliquot 
portion by Almen's reagent (4 grams tannin in 1900 cc. of 50% alcohol 
mixed with 8 cc. of 25% acetic acid), filter, wash, and determine nitro- 
gen. Nx 6.38 = albumin. 

To obtain the casein, subtract the albumin from the total protein. 

Determination of Nitrogen as Caseoses, Amino-compounds, Peptones, 
and Ammonia. — Van Slyke f proceeds as follows : The filtrate from 
the determination of the albumin, as above, is heated to 70° C, i cc. of 
50% sulphuric acid is first added, and afterwards chemically pure zinc 
sulphate to saturation. The mixture is allowed to stand at 70° until the 
caseoses separate out and settle. Cool, filter, wash with a saturated zinc 
sulphate solution slightly acidified with sulphuric acid, and determine 
the nitrogen of the caseoses in the precipitate. 

For Amino-compounds and Ammonia treat 50 grams of the milk in a 



* Allen's Commercial Organic Analysis, 4th Ed., Phila., 1914, 8, p. 156. 
t N. Y. Exp. Sta. Bui. 215, p. 102. 



134 



FOOD INSPECTION AND ANALYSIS. 



250-cc. graduated flask with i gram sodium chloride and a 12% solution 
of tannin, added drop by drop till no further precipitate is formed. Dilute 
to the 250-cc. mark, shake, and filter. Determine the nitrogen in 50 cc. 
of the filtrate, the result being the combined nitrogen of the amino-com- 
pounds and ammonia. 

Distil with magnesium oxide 100 cc. of the filtrate from the tannin salt 
solution, receiving the distillate in a standardized acid, and titrating in 
the usual way for the ammonia. 

Calculate the nitrogen of the peptones by subtracting from the total 
nitrogen that due to all other forms. 

Van Slyke has furnished the following unpublished analysis of a 
sample of milk three months old, kept under antiseptic conditions by 
chloroform. 



Per Cent 
Total N. 


Per Cent 
Sol. Nitrogen. 


Per Cent 

N as Paranuclein, 

Caseoses, and 

Peptones. 


Per Cent 
N as Amino- 
compounds. 


0.561 


0.099 


0.074 


0.025 



DETERMINATION OF MiLK SUGAR. — If a polariscope is available, the 
sugar of milk can most readily and conveniently be determined by optical 
methods. In the absence of a polariscope, the reducing power of milk 
sugar on copper salts may be utilized quite accurately in determining 
the sugar, using either volumetric or gravimetric methods as desired. 

Determination by Polarization. — Wiley Method.* — i. Reagents. — Mer- 
curic Nitrate. — This solution is prepared by dissolving metallic mercury 
in twice its weight of nitric acid of specific gravity 1.42, and adding to 
the solution an equal volume of water. One cc. of this reagent will be 
found sufficient to precipitate the proteins and fat completely from 65 
grams of milk, but if more is employed the result of the analysis is not 
affected. 

Mercuric Iodide Solution. — 33.2 grams of potassium iodide are mixed 
with 13.5 grams of mercuric chloride, 20 cc. of acetic acid, and 640 cc. 
of water. 

Suhacetate of Lead Solution, U. S. P. See page 610. 

Notes. — For the Laurent polariscope, in which the normal weight 
for sucrose is 16.19 grams, the corresponding normal weight for lac- 



■ Am. Chem. Jour., 6, 1884, p. 2S 



MILK AND ITS PRODUCTS. 



135 



tose is 20.496, while for the Soleil-Ventzke instrument, in which the su- 
crose normal weight is 26.048 grams, the corresponding lactose normal 
weight is 32.975.* 

It is customary to employ three times the normal weight of milk 
in the case of the Laurent instrument (viz., 61.48 grams) and twice the 
normal weight in the case of the Soleil-Ventzke (viz., 65.95 grams). 

As it is more convenient to measure the milk than to weigh it, and 
as the volume varies with the specific gravity, the following table is use- 
ful, showing the quantity to be measured in any case, having first deter- 
mined the specific gravity. 



specific Gravity. 


Volume of Milk to be Used. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

16.19 Grams. 


For Polariscopes of 

which the Sucrose 

Normal Weight is 

26.048 Grams. 


1.024 


60.0 cc. 


64 . 4 cc. 


1.026 
1.028 


59-9 cc. 
59.8 cc. 


64.3 cc. 
64. 15 cc. 


1.030 


59-7 cc. 


64 . cc. 


1.032 


59.6 cc. 


63.9 cc. 


1-034 


59-5 cc. 


63.8 cc. 


I -03s 


59-35 cc. 


63.7 cc. 



For ordinary work it is sufficiently close to have a pipette gradu- 
ated to deliver 59.7 cc. if the Laurent instrument is used, and 64 cc. for 
the Soleil-Ventzke. 

2. Process. — Measure as above, the equivalent of 61.48 grams of 
the milk for the Laurent, or 65.95 grams for the Soleil-Ventzke, instru- 
ment into a loo-cc. graduated flask, add, in order to clarify, 2 cc. of acid 
nitrate of mercury solution, or 30 cc. of mercuric iodide solution, or 10 cc. 
of lead subacetate solution. Shake gently and fill to the mark with 
water, then add from a pipette 2.5 cc. of water to make up for the volume 
of the precipitated proteins and fat, insuring 100 cc. of sugar solution. 
Shake thoroughly, filter through a dry paper, and polarize the filtrate, 
which must be perfectly clear, in a 2co-mm. tube. Divide the reading 
by 3 for the Laurent and by 2 for the Soleil-Ventzke instrument. The 
quotient is the percentage of lactose. 

3. Allowance for the Volume of the Precipitate. — This of course varies 
with the content in proteins, and fat, and while the above allowance gives 

*[a]D for lactose = 52.53, [a]z) for sucrose = 66.5, hence for the Laurent instrument 

52.53 : 66.5:: 16.19 : 20.496, 
and for the Soleil-Ventzke instrument 52.53 : 66.5 :: 26.048 ; 32.975. 



136 FOOD INSPECTION AND ANALYSIS. 

in most cases sufficiently close results, it is not exact. Leffmann* recom- 
mends that the amount of water to be added above loo cc. be calculated 
in each case from the percentage of proteins and fat previously found by 
analysis, multiplying the actual weight of the fat in grams in the sample 
taken by 1.075, ^^^ the weight of proteins by 0.8, the sum of the two 
results being the volume in cubic centimeters occupied by the precipitate. 

All calculations are avoided by employing the double-dilution method, 
which is to be recommended when very particular results are required. 

Wiley and Ewell's Double-dilution Method.f — Two flasks are em- 
ployed graduated at 100 and 200 cc. respectively, into each of which 
are introduced 65.95 grams of milk, if the Soleil-Ventzke instrument is 
used (or 61.48 grams in case the Laurent is used) and 4 cc. of the mer- 
curic nitrate solution are added, both flasks being filled to the mark and 
shaken. The contents are filtered and the polarization is made in each 
case in a 400-mm. tube. 

The second reading (that of the more dilute solution) is multiplied 
by 2, and the product subtracted from the first reading; the remainder 
is then multiplied by 2, and the product subtracted from the first read- 
ing (that of the stronger or 100 cc. solution). The result is the cor- 
rected reading, which, divided by 4, gives the exact per cent of milk sugar 
in the sample. This method depends on the fact that within ordinary 
limits the polarizations of two solutions of the same substance are 
inversely proportional to their volumes. 

Determination of Milk Sugar by Fehling's Solution.— Twenty- 
five grams of the milk (24.2 cc.) are transferred to a 250-cc. flask, 0.5 cc. of 
a 30% solution of acetic acid are added and the contents well shaken. 
After standing for a few minutes, about 100 cc. of boiling water are run 
in, the contents again shaken, 25 cc. of alumina cream are next added, 
the flask shaken once more, and set aside for at least ten minutes. The 
supernatant liquid is then poured upon a previously wetted ribbed filter, 
and finally the whole contents of the flask are brought thereon, and the 
filtrate and washings made up to 250 cc. The filtrate must be perfectly 
clear. The milk sugar in a solution thus precipitated would ordinarily 
not exceed ^ of i per cent. Scheibe { after precipitating with copper 
sulphate, adds 2 cc. of saturated sodium fluoride solution to precipitate 
the lime which otherwise would cause an error of 0.10%. 

* Milk and Milk Products, p. 38. 

t Wiley's Agricultural Analysis, p. 278; Analyst, 21, 1896, p. 182. 

X Zeits. Anal. Chem., 40, 1901, p. i. 



MILK AND ITS PRODUCTS. 137 

Volumetric Fehling Process. — From a burette containing the cleai 
milk sugar solution above prepared, run a measured volume into the 
boiling Fehling liquor containing 5 cc. each of copper and alkali solution 
till sufficient has been introduced to completely reduce the copper, con- 
ducting the operation in the manner described in detail on page 615. 

As 0.067 gram of milk sugar will reduce 10 cc. of Fehling solution 

(see p. 616), it follows that the number of cubic centimeters of sugar 

containing solution required for making the test (using preferably the 

average of several determinations) will contain 0.067 gram of milk 

sugar, from which the percentage is readily computed. Thus if 16 cc. 

of the milk sugar solution are necessary to reduce the copper, then 16 

cc. contain 0.067 gram milk sugar. 

250 cc. of solution contain 25 grams milk, 

ICC. '' " " 0.1 « " 

i6cc. " " " 1.6 " " 

and 1.6 grams milk contain 0.067 gram milk sugar. Therefore the 

, ^ . .067X100 „ 

sample contams 7 = 4.19%. 

Gravimetric Fehling Processes.— O'SulUvan-Dejren Method.— Twenty- 
five cc. of the above milk sugar solution are added to the hot mixture of 
15 cc. each of Fehling copper and alkali solutions and 50 cc. water, pre- 
pared as directed on page 615, and the test carried out in accordance with 
the details given on page 618. The weight of the cupric oxide, CuO, as 
formed, may be roughly calculated to anhydrous milk sugar by multiply- 
ing by 0.6024. 

For more accurate results, however, the Defren table, page 619, should 
be used. 

Soxhlet's Method."^ — Twenty-five cc. of milk are diluted with 400 cc. 
.of water in a half-liter graduated flask and 10 cc. of Fehling's copper solu- 
tion are added. Then 8.8 cc. of half-normal sodium hydroxide are run in, 
or a sufficient quantity to nearly but not quite neutralize, the solutior. 
being still slightly acid. The flask is filled to the mark, shaken, and the 
contents filtered, using a dry filter. 

One hundred cc. of the fiUrate are added to 50 cc. of the mixed Fehhng 
solution, which is boiled briskly in a beaker (using 25 cc. each of the 
copper and alkali solution). After boiling for six minutes, fiher rapidly 
through a Gooch crucible provided with a layer of asbestos as described on 
page 618, and wash with boiling water till free from alkah. The asbestos 

* U. S. Dept. of Agric, Bur. of Chem., Bull. 46, p. 41; Bui. 107 (rev.), p. 119. 



138 FOOD INSPECTION AND ANALYSIS. 

film with the adhering cuprous oxide is washed into a beaker by hot dilute 
nitric acid, and after complete solution of the copper is assured, it is again 
filtered and washed with hot water till a clean solution containing all the 
copper is obtained. Add lo cc. of dilute sulphuric acid (containing 200 cc. 
of sulphuric acid, specific gravity 1.84 per liter) and evaporate on the steam- 
bath till the copper has largely crystallized, then carefully continue the 
heating over a hot plate till the nitric acid is driven out, as evidenced by 
the white fumes of sulphuric. Add 8 or 10 drops nitric acid (specific 
gravity 1.42) and rinse into a very clean tared platinum dish of about 
100 cc. capacity, in which the copper is deposited by electrolysis. See 
page 634. 

The weight of milk sugar is determined from that of copper found, 
from the table on page 139. 

If the apparatus for the determination of the copper by the elec- 
trolytic method is not at hand, the cuprous oxide may be weighed 
directly in the Gooch crucible. In order to facilitate drying, it should 
be washed successively with 10 cc. of alcohol, and 10 cc. of ether, after 
which it is dried thirty minutes in a water-oven at 100° C, cooled, and 
weighed. The weight of copper is obtained from the weight of the 
cuprous oxide by the use of the factor 0.8883. 

Mimson and Walker Method. — The milk sugar solution is prepared as 
in Soxhlet's method. For details as to the copper reduction process see 
page 622. 

Relation between Specific Gravity, Fat, and Total Solids of Milk.— 
The close relationship existing between these factors has long been 
known, and many formulae have been devised, whereby, if two of them 
are known, the third may be computed with considerable approach to 
accuracy. The specific gravity and the fat are very readily determined 
by any dairyman, by the aid of a lactometer and the Babcock apparatus. 
The total solids are ascertained with more difficulty, since the use of more 
involved and costly apparatus is necessary, besides considerable tech- 
nical skill. It is therefore common for producers to calculate the total 
solids from the fat and specific gravity, using one of the many tables pre- 
pared for the purpose, based on some one of the best accepted formulae. 
The total solids can thus be calculated to within two or three tenths of 
a per cent. 

The two most commonly used formulae for this purpose are those of 
Hehner and Richmond in England, and Babcock in the United States. 
Hehner and Richmond's formula is 

r = o.255+ 1.2F+ 0.14, 



1 



MILK AND ITS PRODUCTS. 



139 



SOXHLET-WEIN TABLE FOR THE 


DETERMINATION OF 


LACTOSE. 


Milli- ' 


MiUi- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


Milli- 


MUli- 


grams 


grams 


grams 


grams 


grams 
of Cop- 


grams 


grams 


grams 


grams 


grams 


of C!op- 


of Lac- 1 


of Cop- 


of Lac- 


of Lac- 


of Cop- 


of Lac- 


of Cop- 


of Lac- 


per. 


tose. 


per. 


tose. 


per. 


tose. 


per. 


tose. 


per. 


tose. 


lOO 


71.6 


161 


117. 1 


221 


162.7 


281 


209.1 


341 


256-5 


lOI 


72.4 


162 


117.9 


222 


163.4 


282 


209.9 


342 


257.4 


I02 


73-1 1 


163 


118. 6 


223 


164.2 


283 


210.7 


343 


258.2 


103 


73-8 1 


164 


119. 4 


224 


164.9 


284 


211.5 


344 


259.0 


104 


74-6 


165 


120.2 


225 


165-7 i 


285 


212.3 


345 


259-8 


105 


75-3 


166 


120.9 


226 


166.4 1 


286 


213.1 


346 


260.6 


106 


76.1 


167 


121. 7 


227 


167.2 1 


287 


213.9 


347 


261.4 


107 


76.8 


168 


122.4 


228 


167.9 , 


288 


214.7 


348 


262.3 


108 


77-6 


169 


123.2 


229 


168.6 1 


289 


215-5 


•349 


263.1 


109 


78-3 


170 


123.9 


230 


169.4 i 


290 


216.3 


350 


263.9 


IIO 


79.0 


171 


124.7 


231 


170.1 1 


291 


217. 1 


351 


264.7 


III 


79-8 


172 


125-5 


232 


170.9 1 


292 


217.9 


352 


265.5 


112 


80.5 


173 


126.2 


233 


171.6 


293 


218.7 


353 


266.3 


113 


81-3 


174 


127.0 


234 


172.4 


294 


219-5 


354 


267.2 


114 


82.0 


175 


127.8 


235 


I73-I 


295 


220.3 


355 


268.0 


"5 


82.7 


176 


128.5 


236 


173-9 


296 


221.1 


356 


268.8 


116 


83-S 


177 


129.3 


237 


174.6 j 


297 


221 .9 


357 


269.6 


117 


84.2 


178 


130. 1 


238 


175.4 1 


298 


222.7 


358 


270.4 


118 


85.0 


179 


130.8 


239 


176.2 


299 


223-5 


359 


271.2 


119 


85.7 


180 


131.6 


240 


176.9 1 


300 


224 4 


360 


272.1 


120 


86.4 


181 


132-4 


241 


177-7 


301 


225.2 


361 


272.9 


121 


87.2 


182 


133-I 


242 


178-5 


302 


225.9 


362 


273-7 


122 


ll^ 


183 


133-9 


243 


179-3 1 


303 


226.7 


363 


274-5 


123 


88.7 


184 


134-7 


244 


180.1 


304 


227-5 


364 


275-3 


124 


89-4 


185 


135-4 1 


245 


180.8 


305 


228.3 


365 


276.2 


125 


90.1 


186 


136.2 


246 


181. 6 


306 


229.1 


366 


277.1 


126 


90.9 


187 


137-0 


247 


182.4 


307 


229.8 


367 


277-9 


127 


91.6 


188 


137-7 


248 


183.2 


308 


230.6 


368 


278.8 


128 


92-4 


189 


138.5 


249 


184.0 


309 


231.4 


369 


279.6 


129 


93-1 


190 


139-3 


250 


184.8 


310 


232.2 


370 


280.5 


130 


93-8 


191 


140.0 


251 


185-5 


311 


232.9 


371 


281.4 


131 


94-6 


192 


140.8 ' 


252 


186.3 


312 


233.7 


372 


282.2 


132 


95-3 


193 


141. 6 


253 


187.1 


313 


234-5 


373 


283.1 


^33 


96.1 


194 


142.3 


254 


187.9 


314 


235.3 


374 


283.9 


134 


96-9 


195 


143-1 


255 


188.7 


315 


236.1 


375 


284.8 


135 


97-6 


196 


143-9 


256 


189.4 


316 


236.8 


376 


285.7 


136 


98.3 


197 


144.6 


257 


igo.2 


317 


237.6 


377 


286.5 


137 


99-1 


198 


145-4 


258 


191.0 


318 


238.4 


378 


287.4 


138 


99-8 


199 


146.2 


259 


191.8 


319 


239.2 


379 


288.2 


139 


100.5 


200 


146.9 


260 


192-5 


320 


240.0 


380 


289.1 


140 


101.3 


201 


147-7 


261 


193-3 


321 


240.7 


381 


289.9 


141 


102.0 


202 


148.5 


262 


194.1 


322 


241-5 


382 


290.8 


142 


102.8 


203 


149-2 


263 


194.9 


323 


242.3 


383 


291.7 


143 


103-5 


204 


150.0 


264 


195.7 


324 


243-1 


384 


292-5 


144 


104-3 


205 


150.7 


265 


196.4 


325 


243.9 


385 


293-4 


I4S 


105. 1 


206 


151-5 ' 


266 


197.2 


326 


244.6 


386 


294.2 


146 


105.8 


207 


152.2 


267 


198.0 


327 


245-4 


387 


295.1 


147 


106.6 


208 


153-0 


268 


198.8 


328 


246.2 


388 


296.0 


148 


107-3 


209 


153-7 


269 


199-5 


329 


247.0 


389 


296.8 


149 


108. 1 


210 


154-5 


270 


200.3 


330 


247-7 


390 


297-7 


150 


108.8 


211 


ISS-2 1 


271 


201.1 


33^ 


248.5 


391 


298.5 


151 


109.6 


212 


156.0 


272 


201.9 


332 


249.2 


392 


299.4 


152 


no. 3 


213 


156.7 


273 


202.7 


333 


250.0 


393 


300.3 


153 


III. I 


214 


157-5 


274 


203 -5 


334 


250.8 


394 


301.1 


154 


III. 9 


215 


158.2 


275 


204.3 


335 


251.6 


395 


302.0 


155 


112. 6 


216 


159.0 1 


276 


205.1 


336 


252-5 


396 


302.8 


156 


113-4 


217 


159-7 i 


277 


205.9 


337 


253-3 


397 


303-7 


157 


114. 1 


218 


160.4 


278 


206.7 


338 


254-1 


398 


304.6 


158 


114. 9 


219 


161.2 


279 


207.5 


339 


254-9 


399 


305-4 


159 


115.6 


220 


161. 9 


280 


208.3 


340 


255-7 


400 


306.3 


160 


116. 4 




! 






■ 









140 



FOOD INSPECTION AND ANALYSIS. 



wheie T is the per cent of total solids, S the lactometer 
reading, and F the fat. An ingenious instrument known 
as Richmond's milk-scale (Fig. 48) is useful in making 
the calculation, instead of employing either the formula or 
a table. This is constructed on the principle of the slide 
rule, and by its use the specific gravity may be corrected 
to the proper temperature, and the solids calculated from 
the fat and specific gravity. 

Babcock's formula for solids not fat is as follows : 



Solids not fat = 



looS-FS 



-i)(ioo-F)2.5, 



,100 — 1.0753^5 

S being the specific gravity, and F the percentage of 
fat. On this formula he has prepared a table * by means 
of which one may calculate solids not fat agreeing quite 
closely with results obtained by gravimetric analysis.f 
The table on page 141 has been recomputed and enlarged 
from that of Babcock, so as to express results in total 
solids rather than solids not fat. 

Calculation of Proteins. — Van Slyke's % formula for 
calculating proteins (P) from the fat {F) is: 
P=(i^-3)Xo.4 + 2.8. 

Olsen § has devised the following formula for calcu- 
lating proteins from total solids {TS): 

TS 



P=TS- 



1.34 



Approximately 0.8 X proteins = casein. 

The proteins being thus calculated, the sugar may be 
computed by difference. These calculations, while only 
approximate, give quite satisfactory results for normal, 
healthy milk, especially from herds. 

Determination of Acidity. — While milk is still fresh, 
i.e., before it has begun to undergo lactic fermentation, 
it will show an acid reaction,- which is sometimes expressed 
in terms of lactic acid. In view of the fact that 

* U. S. Dept.of Agric, Div. of Chem., Bui. 47, p. 123; Bui. 107 (rev.) 
p. 225. 

t For approximate work Babcock has suggested the following simpli- 
ied formula;: Solids not fat = o.25G + o.2i^ and total solids=o.25G-f- 
1.2F, G being the lactometer reading and F the fat. 

I Jour. Am. Chem. Soc. 30, 1908, p 1182. 

§ Jour. Ind. and Eng. Chem., i, 1909, p. 253. 





KI? 






a^ 






= 


(r - = 


- 


_ 
CD 


tH 


= 


Q. - = 

'" si 


E 






= 


m - 




37<» 1 


~ 


t^ 


w 


= 






= 36^1 


~ 




CO 


z 






E35„-| 


z 


00 


= 






'i*.r,-- 






eo 




05 


^ 


z 


= - 






st^ 


z 


-M 


E 




th 
CO 

D 


CO 






j§0 

- 29 

- Z 

~. a 

- p= 


LO 






z 


= 


< 

-1- 

1- 


CD 


- 


z 


-27 UJ 
-^ 2 
: 
I. 1- 
- 

E263 

:2S 
l?i 
:23 




T^ 










-eo- 
-75- 

-70- 
-66- 

-co? 

65- 


- 




CO 




T-1 




■H 




lO 


-46- 

-to- 

36- 
-32 

3 
.1- 

E 


i 


322 




-tH 




1 '1 




CD 


= 


T-1 



MILK AND ITS PRODUCTS. 



141 



TABLE SHOWING PER CENT OF TOTAL SOLIDS IN MILK CORRESPONDING 
TO QUEVENNE LACTOMETER READINGS* AND PER CENT OF FAT.f 



Per 
Cent 












Lactometer Reading at i 


5.5° c. 


































of Fat. 


22 


23 


24 


25 


26 


27 


28 


29 


30 


31 


32 


33 


34 


35 


36 


o.o 


5- 50 


5-75 


6.00 


6.25 


6- so 


6-75 


7 .00 


7.25 


7.50 


7-75 


8-00 


8.25 


8.50 


8-75 


9.00 


O . I 


5 -62 


5-87 


6.12 


6.37 


6.62 


6.87 


7.12 


7-37 


7 . 62 


7-87 


8.12 


8.37 


8.62 


8.87 


9.1 


O. 2 


5.74 


5-99 


6. 24 


6.49 


6-74 


6-99 


7.24 


7-49 


7-74 


7-90 


8.24 


8-49 


8.74 


8.99 


9. 24 


0.3 


S.86 


6. II 


6.36 


6.61 


5.86 


7-11 


7-36 


7.61 


7.86 


8.11 


8.36 


8.61 


8.86 


9. II 


9-36 


0.4 


5-98 


6.23 


6. 48 


6.73 


6.98 


7-23 


7-48 


7-73 


7.98 


8.23 


8.48 


8.73 


8.99 


9-23 


9-48 


0.5 


6. TO 


6.35 


6.60 


6.85 


7.10 


7-35 


7.60 


7-85 


8.10 


8.35 


8.60 


8.85 


9. 10 


9-35 


9.60 


0.6 


6.22 


6.47 


6.72 


6.97 


7.22 


7-47 


7.72 


7-97 


8.22 


8.47 


8.72 


8.97 


9.22 


9-47 


9-72 


0.7 


6.34 


6.59 


6.84 


7.09 


7-34 


7-59 


7.84 


8.09 


8.34 


8.50 


8.84 


9.09 


9-34 


9-59 


9-84 


0.8 


6.46 


6.71 


6.96 


7.21 


7.46 


7-71 


7.96 


8.21 


8.46 


8.71 


8.96 


9.21 


9.46 


9-71 


9.96 


0.9 


6.58 


6.83 


7.08 


7-33 


7-58 


7.83 


8.08 


8.33 


8.58 


8.83 


9.08 


9.33 


9.58 


9-83 


10.08 


1 .0 


6.70 


6-95 


7. 20 


7-45 


7-70 


7.95 


8.20 


8.45 


8.70 


8.95 


9. 20 


9.45 


9.70 


9-95 


10. 20 


I.I 


6.82 


7-07 


7.32 


7-57 


7.82 


8.07 


8.32 


8-57 


8.82 


9-07 


9-32 


9-57 


9-82 


10.07 


10. 32 


I . 2 


6-94 


7.19 


7-44 


7-69 


7-94 


8.10 


8.44 


8.69 


8.94 


9.19 


9-44 


9.69 


9-94 


10. 19 


10.44 


1.3 


7 .06 


7-31 


7.56 


7-81 


8.06 


8.31 


8.56 


8.81 


9.06 


9-31 


9- 56 


9.81 


10 .06 


10.31 


10. s6 


1.4 


7.18 


7-43 


7.68 


7.93 


8.18 


8.43 


8.68 


8.93 


9.18 


9-43 


9-68 


9-93 


10.18 


10.43 


10.68 


1.5 


7.30 


7-55 


7.80 


8.05 


8.30 


8.55 


8.80 


9 -OS 


9 30 


9-55 


9-80 


10.05 


10.30 


10.55 


10.80 


1.6 


7.42 


7.67 


7-92 


8.17 


8.42 


8.67 


8.92 


9-17 


9.42 


9.67 


9.82 


10.17 


10.42 


10.67 


10.92 


1.7 


7-54 


7.79 


8.04 


8.29 


8.54 


8.79 


9.04 


9.29 


9-54 


9-79 


10 . 04 


10.29 


10.54 


10.79 


11 .04 


1.8 


7.66 


7-91 


8.16 


8.41 


8.66 


8.91 


9. 16 


9.41 


9.66 


9-91 


10-16 


10.41 


10.66110.91 


11.17 


1.9 


7.78 


8.03 


8.28 


8.53 


8.78 


9-03 


9.28 


9-53 


9.78 


10-03 


10.28 


10.55 


10.78 


II .04 


11 . 39 


2.0 


7.90 


8.15 


8.40 


8.65 


8.90 


9-15 


9.40 


9.65 


9.90 


10-15 


10.40 


10.66 


10.91 


11.16 


II .41 


2. 1 


8.02 


8.27 


8.52 


8.77 


9.02 


9-27 


952 


9-77 


10.02 


10 - 27 


10.52 


10.78 


II .03 


II .28 


11.53 


2. 2 


8.14 


8.39 


8.64 


8.89 


9.14 


9-39 


9.64 


9-89 


10.14 


10-39 


10.64 


10.90 


11.15 


11 .40 


11 .65 


2.3 


8.26 


8-51 


8.76 


9.01 


9. 26 


9-51 


9.76 


10.01 


10.26 


10.51 


10.76 


11.02 


11.27 


11.52 


11-77 


2-4 


8.38 


8.63 


8.88 


9.13 


9-38 


9-63 


9.88 


10. 13 


10.38 


10.63 


10.88 


II . 14 


11.39 


11 .64 


11.89 


2-5 


8.50 


8.75 


9.00 


9-25 


9-50 


9-75 


10.00 


10. 25 


10 . 50 


10. 75 


11 .00 


11.26 


II. 51 


11.76 


12.01 


2.6 


8.60 


8.87 


9.12 


9-37 


9.62 


9.87 


10.12 


10.37 


10. 62 


10.87 


11.12 


11.38 


11 . 63 


11.88 


12.13 


2.7 


8.74 


8.9*9 


9.24 


9-49 


9-74 


9-99 


10. 24 


10.40 


10.74 


10.99 


11.24 


11 .50 


11.75 


12.00 


12.25 


2.8 


8.86 


9. II 


9.36 


9-61 


9.86 


10.11 


10.36 


10. 61 


10.86 


11.11 


11.37 


11.62 


11.87 


12.12^12.37 


2.9 


8.98 


9-23 


9.48 


9.73 


9-98 


10.23 


10.48 


10.73 


10.98 


11.23 


11.49 


11.74 


11.99 


12. 24 12.49 


3-0 


9. 10 


9-35 


9.60 


9-85 


10- 10 


10.35 


10.60 


10.85 


11.10 


11.36 


II. 61 


11.86 


12. II 


12.36 12. 6l 


3-1 


9. 22 


9-47 


9.72 


9-97 


10.22 


10.47 


10.72 


10.97 


11.23 


11.48 


11.73 


11.98 


12.23 


12.48 12.74 


3-2 


9-34 


9-59 


9.84 


10 .09 


10.34 


10.59 


10.84 


1 1 .09 


11.35 


11 .60 


11.8s 


12.10 


12.35 


12.61 


12.86 


3-3 


9.46 


9.71 


9-96 


10. 21 


10.46 


10.71 


10.96 


11.22 


11.47 


11.72 


11.97 


12.22 


12.48 


12.73 


12.98 


3-4 


9-58 


9.83 


10.08 


10.33 


10.58 


10.83 


11 .09 


11.34 


11-59 


11.84 


12 .09 


12.34 


12 . 60 


12.85 


13-10 


3-S 


9.70 


9-95 


10. 20 


10.45 


10.70 


10.95 


11.21 


1 1 . 46 


II. 71 


11 .96 


12.21 


12.46 


12.72 


12.97 


13-23 


3-6 


9.82 


10.07 


10.32 


10.57 


10.82 


11.08 


11-33 


11.58 


1 1 . 83 


12.08 


12.33 


12.58 


12.84 


13.09 


13-34 


3-7 


9.94 


10. 29 


10.44 


10.79 


10.94 


II . 20 


II -45 


11.70 


11-95 


12. 20 


12.45 12-70 


12 . 96 


13-21 


13-46 


3-8 


lo .06 


10.31 


10.56 


10.81 


11 .06 


11.32 


11-57 


11.82 


12.07 


12.32 


12.57 12.82 


13.08 


13-33 


13-58 


3-9 


10.18 


10.43 


10.68 


10.93 


II. 18 


11.44 


1 1 . 69 


11.94 


12.19 


12.44 


12.69 12.94 


13.20 


13-45 


13.70 


4.0 


10.30 


10. SS 


10.80 


11.05 


11.30 


11.56 


11.81 


12.06 


12.31 


12.56 


12.81 13-06 


13.32 


13-57 


13.83 


4.1 


10.42 


10.67 


10.92 


11.17 


11 .42 


11.68 


11-93 


12.18 


12.43 


12.68 


12.93 13-18 


13.44 


13-69 


13.9s 


4-2 


10. 54 


10.79 


1 1 . 04 


1 1 . 29 


11-54 


11.80 


12.05 


12.30 


12.55 


12.80 


13-05 13-31 


13.56 


13-82 14.07 


4-3 


10. 66 


lo. 91 


II . 16 


II .41 


11.66 


II .92 


12.17 


12.42 


12.67 


12.92 


13-18 13-43 


13-68 


13-94 


14.19 


4-4 


10.78 


11.03 


II .28 


11-53 


11.78 


I 2 .04 


1 2 . 29 


12.54 


12.79 


13.04 


13-30 13-55 


13-80 


14-06 


14.31 


4-5 


10. 90 


II. 15 


II . 40 


11.65 


11 .90 


12.16 


12.41 


12.66 


12.91 


13.16 


13-42 13-67 


13-92 


14.18 


14.43 


4.6 


1 1 .02 


11.27 


11.52 


11.78 


12.03 


12.28 


12.53 


12.78 


13-03 


13.28 


13-54 13-79 


14.04 


14-30 


14-55 


4-7 


1 1 . 14 


1 1 .40 


1 1 . 65 


11.90 


12.15 


12 .40 


12.65 


12 .90 


13.15 


13-40 


13-66 13.91 


14.16 


14-42 


14-67 


4.8 


11.27 


11-52 


11-77 


12.02 


12. 27 


12.52 


12.77 


13.02 


13-27 


13-52 


13.78 14-03 


14.28 


1454 


14-79 


4-9 


11-39 


11. 64 


11.89 


12.14 


12.39 


12.64 


12.89 


13.14 


13-39 


13-64 


13-90 14-15 


14-40 


14-66 


14.91 


5-0 


ii-Si 


II - 76 


12.01 


I 2 . 26 


12.51 


12.76 


13.01 


13.26 


13-51 


13-76 


1 
14.02 14-27 


14-52 


14-78 


15-03 


S-i 


11-63 


11-88 


12.13 


12.3S 


12.63 


12.88 


13.13 


13.38 


13-63 


13-89 


14.14 14.39 


14.64 


14-90 


IS-15 


S-2 


11.75 


I 2 .00 


12.25 


12. 50 


12.75 


13-00 


13.25 


13-50 


13-75 


14.01 


14.26 14.51 


14-76 lS-02 


iS-27 


5-3 


11-87 


12.12 


12-37 


12.62 


12.87 


13-12 


13-37 


13-62 


13-87 


14-13 


14.38,14.63 


14-88 15-14 


15-39 


5-4 


11-99 


I 2 . 24 


12.49 


12.74 


12.99 


13-24 


13-49 


13-71 


14.00 


14-25 


14.50 14-76 


IS .01 15 . 26 


15-51 


S-S 


I 2 . I I 


12.36 


12.61 


12.86 


13-11 


13-36 


13 ■ 61 


13-86 


14.12 


14-37 


14.62 14.88 


15-13 15-38 


15-63 


5.6 


12.23 


12.48 


12.73 


12.98 


13-23 


13.48 


13-73 


13-99 


14.24 


14.49 


14.75 15.00 


15-25 15-50 


I5-7S 


5-7 


12.35 


12 . 60 


12.85 


13.10 


13-35 


13-60 


13.85 


14- 1 1 


14-36 


14.61 


14.87jlS.12 


15.37 


15-62 


15-87 


5.8 


12.47 


12.72 


12.97 


13-22 


13-47 


13-72 


13-97 


14. 22 


14-48 


14.74 


14.99 15.24 


15-49 


15-74 


15-99 


S-9 


12.59 


12.84 


13-09 


13-34 


13-59 


13-84 


14.10 


14-35 


14-60 


14.86 


15.11 15.36 


15.61 


15-86 


16. 13 


6.0 


12.71 


12 .96 


13-21 


13.46 


13.71 


13.96 


14. 22 


14.47 


14-72 


14-98 


15.23 15.48 


15-73 


15.98 


16. 24 



*The lactometer reading is expressed in whole numbers for convenience. The true specific gravity 
Corresponding to a given lactometer reading is obtained by writing i.o before the lactometer reading. 
Thus, 1.026 is the specific gravity corresponding to lactometer reading 26, etc. 

t An. Rep. Mass. State Board of Health, 1901, p. 445. (Analyst's Reprint, p. 25.) 



142 FOOD INSPECTION AND ANALYSIS. 

the acidity of " sweet " milk is due partly to the presence of acid phos- 
phates and partly to dissolved carbonic acid in the milk, and not to lactic 
acid, which is probably absent, a better plan is to express the acidity in 
terms of the number of cubic centimeters of tenth-normal alkali necessary 
to neutralize a given quantity of the milk, either 25 or 50 cc, using phenol- 
phthalein as an indicator. See also page 1033. 

If it is desired to calculate the acidity in terms of lactic acid, multiply 
the number of cubic centimeters of tenth-normal alkali used by 0.897, and 
divide by the number of cubic centimeters of milk titrated, the result 
being the percentage of lactic acid. 

MODIFIED MILK. 

A comparison of the composition of cow's milk and human milk, as 
in the following table by Dr. Em^mett Holt,* shows very marked differ- 
ences. 

Woman's Milk, Cow's Milk, 

Average. Average. 

Fat 4-00 3.50 

Sugar 7.00 4.30 

Proteins 1.50 4.00 

Ash 0.20 0.70 

Water 87.30 87.50 

The per cent of fat in the two kinds of milk is nearly the same. There 
is, however, too little sugar and an excess of proteins and ash in the milk 
of the cow, assuming human milk as the ideal infant food, so that in 
basing a diet for infants on the basis of human milk considerable modi- 
fication is necessary. Moreover, aside from the actual variation in the 
amount of ingredients, there are certain inherent differences in the char- 
acter of the same ingredient, as found in the milk of the cow and in 
human milk. The proteins of cow's milk, are for instance, found to be 
much more difficult of digestion than those of woman's milk, and the 
same is probably true of the fat. Aside from the mere statement of a 
few of these differences, it is obviously beyond the scope of this work to 
discuss this phase of the subject in detail, reference being made, how- 
ever, to such books as Dr. T. M. Rotch's " Pediatrics," and " Infancy 
and Childhood " by Dr. Emmett Holt, for full particulars. So great 
has been the demand by physicians for "modified milk" for infant 
feeding, that laboratories for this exclusive purpose have been established 

* "Infancy and Childhood." 



MILK AND ITS PRODUCTS. 



143 



in many of the larger cities, in which not only is milk prepared in 
accordance with certain fixed formulae supposed to be adapted to average 
infants of varying age, but milk of any desired composition is prepared, 
in accordance with special prescriptions of physicians to apply to indi- 
vidual cases. 

Methods and Ingredients. — The proteins and the ash in cow's milk 
are much higher than in human milk, and both are brought to the proper 
degree of reduction by diluting the milk with water. Milk sugar is 
increased by the addition of lactose, and the fat is increased or diminished 
by addition of cream or by skimming. 

The dilution of cow's milk with a measured amount of water shows 
the following results on the proteins and ash: 





Cow's Milk. 


Diluted 
Once. 


Diluted 
Twice. 


Diluted 
Three Times. 


Diluted 
Four Times. 


Proteins. . . ........ 


Per cent. 
4.00 
0.70 


Per cent. 
2.00 

0-35 


Per cent. 

1-33 
0.23 


Per cent. 
I.OO 
0.18 


Per cent. 
80 


Ash 


0.14 





The ingredients commonly employed for modifying milk are (i) cream, 
containing 16% of fat, (2) centrifugally skimmed milk, otherwise known 
as "separator milk" from which the fat has been removed, (3) milk 
sugar, or a standard solution of milk sugar of, say, 20% strength, and 
(4) lime water. Unusual care should be taken in the selection of the 
milk supply to insure cleanness, purity, and freshness, as well as in the 
care of utensils, etc., used in the laboratory, which should in all cases 
be scrupulously clean. Samples prepared in accordance with a given 
formula or formulae are pasteurized in separate bottles, or, if desired, 
sterilized, and after stoppering with cotton are kept on ice. 

FormulcB. — It is obviously impossible to establish formulae univer- 
sally applicable even to healthy infants, but the following may be 
regarded as typical formulae, representing the composition of modified 
milk to suit the needs of an average growing infant during its first year: 



Period. 


Fat. 


Proteins. 


Sugar. 


Third to fourteenth day 

Second to sixth week 


Per Cent 

2 

2-5 

3 

3-5 

4 

3-5 


Per Cent 
0.6 
0.8 
I.O 

I-S 

2 

2-5 


Per Cent 
6 
6 
6 
/ 
7 
3-5 


Sixth to eleventh week 

-Eleventh week to fifth month.. 
Fifth to ninth month 


Ninth to twelfth month 



144 



FOOD INSPECTION AND ANALYSIS. 




Fig. 49.— The "Materna" 
Graduate for Modifying 
Milk. 



Milk according to the above formuloe can 
be very simply prepared by the aid of a spe- 
cially made graduate known as the " Materna " 
and shown in Fig. 49. 

Sodium Citrate has long been used in modify- 
ing milk in cases where the casein forms large 
lumps which pass through the body undigested. 
England * attributes the beneficial action to the 
formation of sodium chloride with the hydro- 
chloric acid of the stomach which influences the 
digestion of the protein. Van Slyke and Bos- 
worth t more recently have observed that sodium 
citrate reacts with calcium caseinate, forming 
sodium caseinate or sodium-calcium caseinate. 
With 0.4 gram per 100 cc. no curdling takes 
place, with smaller amounts the curd is more or 
less soft, depending on the amount. 



ADULTERATION OF MILK. 

Systems of Milk Inspection. — A typical method of general food inspec- 
tion has already been outlined (see pp. 6 and 8), which may easily be 
modified to include the inspection of milk in connection with other foods, 
or to provide for a system of milk inspection exclusively. In the exam- 
ination of such a perishable food as milk, it has not been found practicable 
for the analyst to reserve for the benefit of the defendant a sealed sample, 
as in the case of other foods, but experience has shown it had best be 
made the duty of the collector or inspector to give a sealed sample of 
milk to the dealer, when the latter requests it at the time of taking the 
sample. For this purpose the collector is provided with small bottles 
and sealing paraphernalia, in addition to the tagged sample bottles or 
cans in which he collects the milk. The collector should use the same 
precautions for obtaining a perfectly fair representative sample as does 
the chemist in making the analysis, i.e., he should carefully pour the 
milk from the original container into an empty can or vessel and back 
again, before taking his sample. 

Each sample is properly numbered by the collector in presence of the 
dealer, and the data as to the taking of the sample entered at once under 



* Jour. Amer. Med. Assn., 47, 1906, p. 1241. 

t N. Y. State Agr. Exp. Sta. Tech. Bui., 34, 1914. 



MILK AND ITS PRODUCTS. 145 

the proper number in the collector's book. If a sealed sample is given, 
it should bear the same number as the sample reserved for analysis, and 
a receipt should invariably be required from the dealer, as evidence that 
his request for a sealed sample has been complied with. 

Milk Standards Fixed by Law. — In localities where a systematic form 
of milk inspection prevails, there is usually in force a statute fixing the 
legal standard for the total solids, and in many cases for the fat or for 
the solids exclusive of fat. In some states the statute is so drawn that 
any deviation from the legal standard constitutes an adulteration in the 
eye of the law, and hence the offender, who has such milk in his possession 
with intent to sell, is liable to the same fine as if he actully added water 
or a foreign substance to the milk. 

In other states a distinction is made by the statute between milk that 
is simply below the legal standard of total solids, and milk containing 
actually added ingredients (water or otherwise), a much lighter fine being 
imposed for the former than for the latter offense. Where such a dis- 
tinction prevails, it often becomes incumbent upon the analyst to show 
to the satisfaction of the court, in case of milk low in solids, whether or 
not the milk has been fraudulently watered after being drawn from the 
cow, it being well understood that cows may give milk below the standard. 

The U. S. standards for some years in force fixed the minimum 
limits of 8.5% for solids not fat and 3.25% for fat, but more recently it 
has seemed impracticable to fix minimum limits that will apply to all 
sections and the state and municipal standards have been deemed suf- 
ficient. These latter are by no means uniform. The minimum limits 
for total solids range from 11 to 13% and for fat from 2.5 to 3.7 %. 

Pure milk that is low in solids may owe its deficiency either to poor 
feeding, or to an inherent tendency on the part of the cow to give milk 
always of poor quality. Thus the Holstein cow, more than any other 
breed, is open to the charge of sometimes giving milk below the standard.* 
That the Holstein cow is a favorite with the producer is by no means 

* This statement should not be taken as condemning the Holstein, for it is true that cows 
of this breed often give milk far above the standard. A large number of samples of milk 
of known purity from Holsteins analyzed by the writer have been found to be of excellent 
quality. It is a curious fact that among the samples of known purity analyzed by the Massa- 
chusetts Board of Health, both the lowest and highest total solids on record came from a 
Holstein cow; the lowest recorded total solids in a " known purity" milk being 9.96 per 
cent, (seventh annual report of Massachusetts State Board of Health, Lunacy, and Charity, 
p. 160), and the highest being 17.06 per cent, (twenty-second annual report of the Massa- 
chusetts State Board of Health, p. 405). 



146 FOOD INSPECTION AND ANALYSIS. 

Strange, from the fact that no other breed can with moderate feeding 
be made to give so large a quantity of milk. 

Wherever there is a statute fixing the standard for milk, it commonly 
provides also that the addition of any foreign substance whatsoever con- 
stitutes an adulteration. 

Forms of Adulteration. — Milk is ordinarily adulterated (i) by 
watering, (2) by skimming, (3) by both watering and skimming, and 
(4) by the addition of one or more foreign ingredients. 

Watering and Skimming. — The fact that milk is found below the 
standard of total solids, while more often due to an excess of water, may 
also be due to a deficiency in fat. In one case the milk is commonly 
termed watered, and in the other skimmed, using the terms broadly and 
not necessarily meaning actual and fraudulent tampering with the milk. 
In a third case, and almost invariably fraudulently, both watering and 
skimming may be found to have been practiced on the same sample. 
The analyst judges which of these causes have produced a milk low in 
solids, by a careful study of the relation between the percentages of total 
solids, fat, and solids not fat. 

If both the total solids and solids not fat are abnormally low, and 
the proportion of fat to solids not fat about the same as, or higher than, 
in a normal milk, it is generally safe to assume that the sample has been 
watered; if both the total solids and the fat are well below the standard, 
and the solids not fat nearly normal, then the milk has undoubtedly been 
skimmed; if, in the third place, the total solids and the solids not fat are 
proportionally reduced below the standard, w-hile the ratio of fat to solids 
not fat is abnormally small, it is safe to adjudge the milk to be low by 
reason of both skimming and watering. 

Milk of Known Purity. — It is difficult to place the minimum figure 
for total solids, below which a milk sample may safely be pronounced 
by the analyst as fraudulently watered after having been drawn from 
the cow. Nearly nine hundred samples of milk of known purity from 
various breeds of cow, milked in the presence of an inspector, have been 
analyzed in the Department of Food and Drug Inspection of the Massa- 
chusetts State Board of Health, extending over a period of fifteen years, 
and among these are many samples from Holstein cows. It is extremely 
rare that any of these known purity samples have been found with total 
solids as low as 11%, though there are instances where total solids have 
run as low as 10%. 



MILK AND ITS PRODUCTS. 147 

It is safe to assume that in the few cases on record showing less than 
10.75% of total solids, either there was something decidedly abnormal 
about the health of the cow, or, through some accident, the cow was only 
partially milked, it being a well-known fact tnat the last fraction of the 
milking includes the larger percentage of fat. (See page 113.) 

It is therefore nearly always safe to condemn a milk standing below 
10.75 ^s fraudulently watered, if at the same time it has a proportionately 
high per cent of fat. 

The average total solids of 800 samples of milk of known purity analyzed 
by the Massachusetts Board up to and including the year 1890 amounted 
to about i3i%. 

It is rare indeed to find a herd of ten or more well-fed cows of mixed 
breeds in which the average milk of the herd falls below i2j% of 
solids. 

The milk of forty-seven Holstein cows, examined in 1885, was 
found to contain an average of 12.51% of total solids, while the 
milk of eleven Jerseys examined in the same year averaged 14.02% 
of solids. Thpse examples represent the two extremes commonly met 
with. 

Variation in Standard. — In Massachusetts the law fixes a different 
standard for total solids in milk during the summer, or pasture-fed season, 
from that in force during the winter, or stall-fed period. From April 
to September inclusive the legal standard is 12% of total solids, of which 
9% are solids not fat, and from October to March inclusive it is 13%, of 
which 9.3% are solids not fat. Bearing on the question of difference in 
normal quality of milk during the two periods, averages were taken of the 
milks collected by the corps of inspectors of the Massachusetts Board of 
Health during a month in each period, December and June being selected 
as most typical, and during these months all the samples were analyzed 
both for total solids and fat. The samples were taken from stores, milkmen, 
and producers, and represented as nearly as possible the milk as actually 
sold to the consumers. In making the averages, all samples of skimmed 
milk, as well as all ss>,mples standing above 17% of total solids, or under 
10.75%, were deducted. The results are summarized as follows: 



148 



FOOD INSPECTION AND ANALYSIS. 



QUALITY OF MILK SOLD IN MASSACHUSETTS CITIES AND TOWNS IN 
WINTER AND SUMMER. 





December. 




Number 

of 
Samples. 


Total Solids. 


Fat. 


SoKds 
not Fat. 
Average 
Per Cent. 




Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Cities 

Towns 

Summary .... 


403 

99 

502 


16.86 
15.48 
16.86 


10.88 
12.02 
10.88 


13.21 
13-44 
13-32 


8.50 
6.65 
8.50 


2.40 

3-5° 
2.40 


4-37 
4-48 
4.42 


8-74 
8.96 
8.8s 




June. 




Number 

of 
Samples. 


Total Solids. 


Fat. 


Solids 
not Fat. 
Average 
Per Cent. 




Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Highest 
Per Cent. 


Lowest 
Per Cent. 


Average 
Per Cent. 


Cities 

Towns 

Summary .... 


3" 
76 

387 


16.90 

15-71 
16.90 


IO-75 
10.99 

IO-75 


12.67 
12.63 
12.65 


8.80 
7.10 
8.80 


2.10 
3.00 
2.10 


4-03 
4.09 
4.06 


8-54 

8.54. 

8.54 



It is interesting to note that the average for total solids of the 88g 
samples examined for both months stands at just 13%, of which 4.24% is 
fat and 8.76 is solids not fat. 

Rapid Approximate Methods of Determining the Quality of Milk. — 
The Lactometer. — ^A rough idea of the quality of milk can be gained by the 
use of the lactometer (page 118), but, in view of the fact that a low specific 
gravity may be the result either of a watered milk or of a milk high in fat, 
good judgment is necessary in connection with its use. A milk of good 
standard quality should have a specific gravity between the limits of 
1.027 and 1-033. ^ watered milk would run below the former and a 
skimmed milk above the latter figure, though a milk unusually rich in fat 
would also run low. It should easily be apparent from the taste and appear- 
ance of the milk, whether a low specific gravity is due to watering or 
unusual richness in fat. The fact should also be recognized, that a milk 
sample may be far below the standard, and still show a specific gravity 
within the limits of pure milk, by skillfully subjecting the milk to both 
skimming and watering. 

The Ladoscope. — Feser's lactoscope (Fig. 50) gives an approximation to 
the amount of fat in milk, and its use, especially in connection with the 
lactometer, is of some value. This instrument consists of a graduated glass 
barrel, a, into the bottom of which i;. accurately fitted the stopper, bearing 



MILK AND ITS PRODUCTS. 149 

a white glass cylinder, having black lines thereon. Four cc. of milk are 
introduced into the barrel by means of a pipette, c, and water is added 
with thorough mixing till the translucence of the mixture is sufficient to 
allow the black lines to be perceptible through it. The height of the level 
of milk and water in the barrel a is then read off, the number indicating 
roughly the percentage of fat in the sample. 

As in the case of the lactometer, the purity of a milk sample cannot 
be positively established by the lactoscope alone. For instance, a watered 
milk abnormally high in fat would often be found to read within the limits 
of pure milk, when as a matter of fact its total solids would be below stand- 
ard. By a careful comparison of the readings of both the lactoscope and 
lactometer, however, it is rare that a skimmed or watered sample could 
escape detection. 

Thus, if the specific gravity by the lactometer is well within the limits 
of pure milk, and the fat, as shown by the lactoscope, is above 3^ per 
cent., the sample may be safely passed as pure, or as conforming to the 
standard. 

A normal lactometer reading in connection with an abnormally low 
lactoscope reading shows both watering and skimming, and with an 
abnormally high lactoscope reading shows a milk high in fat, or a cream. 
With the lactoscope reading below three, and a low lactometer reading, 
watering is indicated. A lactometer reading above thirty-three, and a 
low lactoscope reading, indicate skimming. 

Heeren's Pioscope. — This instrument consists of a hard-rubber disk, 
having in the center a shallow receptacle, the circular rim of which is raised 
above the level of the disk. Into this receptacle are introduced a few 
drops of the milk to be tested, and a circular cover-glass containing a 
number of variously tinted segments is placed over the receptacle, which 
spreads the milk out into a thin layer, and causes it to assume a tint against 
the black background that can be matched with one of the colors on the 
glass, the various tints indicating milks of various grades from the very 
poorest to rich cream. This test is at best a very rough one. 

Examination of the Milk Serum. — Detection of Added Water. — 
This may often be detected by determining the specific gravity or the 
degree of refraction of the milk serum, since it has been found that under 
fixed conditions the composition of the milk serum, or clear " whey," 
is more constant than that of the milk itself. Hence any considerable 
amount of watering is manifest from the physical constants of the serum. 
-In using this method the analyst should carefully work out his own 



150 



FOOD INSPECTION AND ANALYSIS. 



Standards for comparison, by personal experiment on milk of known 
composition to which varying amounts of water have been added using 
the same conditions for obtaining the serum in all cases. 




f"''v>'^ /•]!! 




Fig. so. — Feser's Lactoscope. 

Preparation of the Serum. — In addition to natural souring, the fol- 
lowing methods of preparing the serum have been described : 



MILK AND ITS PRODUCTS. 151 

1. Acetic Acid Method.^— To loo cc. of the milk at about 20° C, add 
2 cc. of 25% acetic acid (sp. gr. 1.035), ^^ weW, and heat on a water- 
bath at 70° C. for 20 minutes. Cool 10 minutes in ice-water and filter. 

2. Calcium Chloride Method. '\ — Mix thoroughly 90 cc. of the milk 
and 0.75 cc. of calcium chloride solution (sp. gr. 1.1375; refraction diluted 
I : 10, 26). Heat in a boiling water-bath under a reflux condenser for 
15 minutes, cool to 20° C, mix without shaking, and filter. 

3. Asaprol Method. % — The reagent consists of 30 grams of asaprol 
and 55.89 grams of crystallized citric acid in i liter of water, if the 
refraction is not 36.3 at 20° C, add citric acid or water as required. Mix 
equal volumes of the milk and the reagent, shake well, and filter. 

4. Copper Sulphate Method. I — Dissolve 72.5 grams of crystallized 
copper sulphate in water and dilute to i liter. The refraction should 
be adjusted if necessary so as to be 36° at 20° C. To 4 volumes of the 
milk add i volume of the copper solution, shake well, and filter. 

Of the above Lythgoe's copper sulphate method has the advantage 
of simplicity, accuracy, and narrow range of refraction for pure milk. 

Specific Gravity. — The specific gravity of the clear filtrate, obtained 
by the method described above, is taken at 15° C, with the Westphal 
balance. 

Immersion Refractometer Reading. — The instrument used is the Zeiss 
immersion or dipping refractometer described on pages 97 to 107. The 
serum, prepared as directed in a preceding paragraph, is examined in one 
of the small beakers accompanying the apparatus at a temperature of 20° C. 

Composition and Serum Constants of Milk of Known Purity. — In 
the table on page 152 are given Lythgoe's results || on 33 samples from 
individual cows and 4 samples from herds, all of known purity. He 
concludes after several years' experience with samples of known purity 
that the presence of added water is shown by a refraction of less than 
36°, furthermore that when the protein exceeds the fat the sample is 
skimmed milk. 

Nitrates. — Pure milk, free from contamination with stable filth, con- 
tains no nitrates; well water, however, often contains a sufficient amount 
to enable the detection of a 10% admixture in milk. 

* Woodman, Jour. Amer. Chem. Soc, 21, 1899, p. 503. 

fAckerman, Zeits. Unters. Nahr. Genussm, 13, 1907, p. 186. 

X Baier and Neumann, Ibid., p. 369. 

§Lythgoe, Mass. State Bd. Health Rep., 1908, p. 38. 

II Ibid., Rep. 1910, p. 44. 



152 



FOOD INSPECTION AND ANALYSIS. 



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MILK AND ITS PRODUCTS. 153 

The diphenylamin test, first employed by Soxhlet to detect nitrates 
in milk, has since been variously modified.* 

Place in a small porcelain crucible one cc. of a solution of o.i gram 
of diphenylamin in loco cc. of concentrated sulphuric acid and allow 
a few drops of the milk serum to flow over the surface. A blue color 
appearing within lo minutes indicates the presence of nitrates. On 
longer standing, a brown color forms, whether or not nitrates are present. 
According to Willeke, Schellbach, and Jilke f milk to which hydrogen 
peroxide has been added also gives the blue color. 

The delicacy of the test is increased by adding to the reagent a small 
amount of powdered sodium chloride shortly before using. 

Determination of Freezing Point.— Beckmann,t who proposed this 
means of detecting added water, reached the conclusion that the freezing 
point of pure milk ranged from -0.58° to -0.54° C, and that water 
influences the result in proportion to the amount added. While most 
of the later investigators find that -0.58° is none too high for the mini- 
mum limit, Gr liner § reports a maximum for single cows of —0.535°, 
Pins II of -0.529°, Stutterheim 1; of -0.52° and Konig ** of -0.515°. 
Mixed herd milk appears seldom to fall outside of the limits -0.57° and 
-0.53°. Most authors agree that the per cent of fat, as well as the age, 
breed, period of lactation, and feed of the cow have little or no influence. 
Stutterheim, however, found that poor feeding gave freezing points in the 
case of eight cows from -0.52° to -0.536°. Souring and the addition 
of certain preservatives without question lower ihe freezing point (Bon- 
nema,tt Keister ||). Gooren ** finds that homogenizing, pasteurizing, 
and sterilizing also lower it. 

While the freezing point is undoubtedly a valuable constant and will 
detect with reasonable certainty as high as 10% of water, whether it serves 
for finer distinctions and is as reliable a means of diagnosis as either the 



♦Moslinger, Ber. 7 Versain. bayer. chem. Berlin, 1889; Richmond, Analyst, 18, 1893, 
p. 272; Hefelmann, Zeits. offentl. Chem., 7, 1901, p. 200; Reisz, Pharm. Ztg., 49, 1904, 
p. 608; see also Tillmans, Zeits. Unters. Nahr. Genussm., 20, 1910, p. 676. 

tZeitz. Unters. Nahr. Genussm., 24, 1912, p. 227, 

t Milch Ztg., 23, 1894, p. 702. 

§ Ann. 1st. Agric, 6, 1901-1903, p. 27. 

11 Inaug. Dis., Leipzig, 1910. 

H Pharm. Weekbl., 54, 1917, p. 458. 

** Gooren, Centbl. Bakt., 35, II, 191 2, p. 625. 

tt Pharm. Weekbl., 43, 1906, No. 18. 

tt Jour. Ind. Eng. Chem., 9, 1917, p. 862. 



154 FOOD INSPECTION AND ANALYSIS. 

solids-not-fat or the refraction, can be settled only by numerous determina- 
tions on authentic samples produced under a variety of conditions. The 
apparatus, although not so expensive as the immersion refractometer, 
requires more skill in manipulation. The possible presence of considerable 
lactic acid, preservatives, and common salt, the latter added to offset the 
effects of watering, should always be taken into account. 

The apparatus and general process of determination are described 
on page 4.9. 

Otlier Milk Constants. — The Viscosity of milk has been determined 
by various chemists. Kooper * claims to be able to detect 5% of added 
water b}'' this constant. 

The Specific Heat of milk and milk products has been determined 
by Hammer and Johnson f because of its practical value in pasteurizing 
and refrigerating, also in the manufacture of butter and ice cream. 

The Electrical Conductivity is stated by Favilli | to be unsatisfactory 
for determining added water in milk. 

Capillary and Adsorption Phenomena have been studied by Kreidl 
and Lenk. § Cow's milk on bibulous paper forms three concentric zones — 
casein, fat, and water. On dilution to a certain point no casein zone is 
formed. 

Oxidation Index. — This constant, proposed by Comanducci,|| repre- 
sents the number of cubic centimeters of N/io potassium permanganate 
required in the presence of sulphuric acid to oxidize i cc. of milk. It 
is designed to distinguish cow's from goat's and sheep's milk. 

Systematic Examination of Milk for Adulteration.— If a 

large number of samples of milk have to be examined daily for adul- 
teration, it may be an advantage to submit all to a preliminary test with 
the lactoscope and lactometer, excluding from further analysis, as above 
the standard, such samples as pass certain prescribed limits which experi- 
ence has proved these tests to be capable of showing to an experienced 
observer, and submitting the remainder to a chemical analysis. In 
using such an instrument as the lactoscope for this purpose, the individual 
element is a most important consideration, and the use of this instrument 

* Milchw. Zentbl., 43, 1914, p. 169. 

t Iowa Agric. Exp. Sta., Res. Bui. 14, 1913, p. 451. 

% Riv. sci. latte, i, 191 1, p. ZZ- 

§ Pfliiger's Arch. Ges. Physiol., 141, 191 1, p. 541. 

11 Gaz. chim. Ital, 36 II, 1906, p. 813. 



MILK AND ITS PRODUCTS. 155 

in the milk laboratory should be limited only to a skillful operator, 
accustomed to interpret its results. 

The method used by the Mass. Board of Health has been to submit 
all samples to the regular test for solids, and such samples as fall below 
the legal standard for solids, are further examined for fat. 

Total Solids, Ash, and Fat.— It is presupposed that the analyst is 
equipped with a sufficient number of platinum dishes for the number 
of milk samples daily analyzed. It is a convenience to have these dishes 
numbered, and instead of weighing each dish_, to have a system of num- 
bered counterweights (Fig. 51, A) corresponding to the dishes. The 
counterweights recommended by Leach for this purpose are easily made 
from half inch lead pipe, cut to the appropriate length and flattened. 
Each weight is then carefully adjusted to its appropriate dish, by trim- 
ming off the weight with a knife, or by adding bits of lead scraps, if 
necessary, by simply prying open in the center, inserting the required 
amount of scrap, and then closing by a blow of the hammer, the weight 
being plainly numbered before final adjustment. A rack is provided 
by the side of the balance-case (Fig. 51) with slits for holding the weights 
in their appropriate places. Such a set of counterweights is not difificult 
to make, requires very little care to keep in adjustment, and is an 
immense labor-saving device. 

Details of Manipulation. — The method of examining large numbers 
of milk samples, long in use in the laboratory of the Massachusetts State 
Board of Health, has proved to be rapid, easy, and accurate. It is here 
given in some detail. 

From 12 to 20 samples of milk are conveniently weighed out at a 
sitting, the unopened sample cans or bottles being contained in a tray 
at the left of the operator on a low stand, another low stand and tray 
being at this right hand for the cans, after removing the weighed portions, 
and a third tray on the table at the right of the balance for the platinum 
dishes with the weighed samples. The analyst enters the number of 
the platinum dish in his note-book, or on a card,* in line with the number 
of the milk sample, verifies the correctness of the counterweight, and 
weighs out exactly 5 grams of the milk with the aid of a pipette, after 
first having throughly mixed the sample. This operation is repeated 
with all the samples, the platinum dishes containing the weighed amounts 



* Specially ruled library cards, as shown on page 157, are useful for this purpose. 



156 



FOOD INSPECTION AND ANALYSIS. 



of each being placed in succession on the tray, which is finally carried to 
the water-bath and the dishes transferred thereto. The time required 
for weighing out 1 2 samples of milk in this manner is about fifteen minutes. 
The water-bath is inclosed in a hood, and the shding front is so arranged 
that it can be shut down and locked, so that if the analyst has to leave 




Fig. 51. — Set of Counterweights for Numbered Platinum Dishes, in a Convenient Rack. 

A. One of the Counterweights. 

B. Platinum Dishes. 

the laboratory during the three hours required for the evaporation, he 
can swear in court that the samples could not be tampered with during 
his absence (see page 20). 

WTien ready to make the second weighings for the total soHds, each 
dish is taken from contact with the steam, and, while still hot, is wiped 
dry with a soft towel, till twelve of the dishes are placed on the tray, 
which is then taken to the balance. Experience has shown that with 
ordinary rapidity in weighing, twelve of the residues may be thus dealt 
with at a time without the need of a desiccator, the gathering of moisture 
during that time being inappreciable, excepting in very damp weather, 
when a less number of dishes should be removed at a time from the bath. 
In making the second weighing, and employing the counterweight as 







MILK AND 


ITS 


PRODUCTS. 


157 


( 




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Soecimen Card for Analyst's Records of Milk Analyses. To be filed in a cabinet. 



158 



FOOD INSPECTION AND ANALYSIS. 



before, the exact net weight of the residue is at once ascertained and 
entered in the appropriate column in the note-book. MultipHed by 
20 it gives at once the percentage of total soHds. 

It is a great saving of time to weigh out exactly 5 grams as above 
described. The knack of quickly measuring out the exact amount is easily 
acquired with practice, the 5 -gram weight is the only one required for 
the operation with the counterweight of the dish, and the laborious figuring 
of percentage due to using a fraction above or below the 5 grams of milk 
is avoided. 

Such samples as are found to' stand below the standard of total solids 
are further examined for fat by the Babcock process (p. 123), entering 
the number of the fat bottle in the note-book in the appropriate column, 
and subsequently the percentage of fat. 

Ordinarily the specific gravity is not determined, excepting in some 
cases of badly watered milk, when, for purposes of a check, it is customary 
to take the specific gravity, and calculate the solids from the gravity and 
the fat by Babcock's formula (p. 140), or the Richmond sliding scale, and 
compare the result with the figure directly determined. 

The ash is rarely weighed except in special cases. 

The dishes containing the dry residues are easily cleaned by first 
burning to an ash and cooling, after which they are treated successively 
with strong nitric acid, which is poured from one to another, the dishes 
being rinsed thoroughly with water and finally heated to redness. 

A convenient device for ashing a large number of residues for purposes 
of cleaning the platinum dishes and for final heating is the incinerator 
shown in Fig. 52, made of Russia iron. The digestion stand for the 
Kjeldahl method (Fig. 27a) may also be used. 




Fig. 52. A Sheet-metal Incinerator, Specially Used for Ashing Milk Residue. 



ADDED FOREIGN INGREDIENTS. — Passing over such mythical 
adulterants as chalk and such rarely used substances as calves' brains, 
starch, glycerin, sugar, etc., often discussed in manuals on milk, but 



MILK AND ITS PR0r3UCTS. 159 

with few authentic instances of their actual occurrence, the commonly 
found adulterants may be divided into two classes: coloring matters and 
preservatives. 

The coloring matters almost exclusively used are annatto, azo-colors, 
and caramel. The preservatives commonly met with are formaldehyde, 
boric acid, borax, and sodium bicarbonate. Rarely salicylic and benzoic 
acids are found. 

Coloring Matters. — While it is more often true that an artificially 
colored milk is also found to be watered, the coloring being added to 
cover up evidence of the watering, it is not uncommon to find added 
coloring matter in milk above the standard.* 

About 95% of the milks found colored in Massachusetts showed on 
analysis the fraudulent addition of water. 

Statistics of the Massachusetts State Board of Health show that out 
of 48,000 samples of milk collected throughout the state and analyzed 
during nine years (from 1894 to 1902 inclusive) 342 samples or 0.7% 
were found to contain foreign coloring matter. Of these samples, about 
67% contained annatto, approximately 30% were found with an azo- 
dye, and about 3% with caramel. 

Until comparatively recently annatto was employed almost exclu- 
sively for this purpose. Caramel is least desirable of all the above colors 
from the point of view of the milk-dealer, in that it is difficult to imitate 
with it the natural color of milk, by reason of the fact that the caramel 
color has too much of the brown and too little of the yellow in its com- 
position. Annatto, on the other hand, when judiciously used and with 
the right dilution*, gives a very rich, creamy appearance to the milk, even 
when watered, which accounts for its popularity as a milk adulterant. 
Of late, however, the use of one or more of the azo-dyes has been on 
the increase, and so far as a close imitation of the cream color is con- 
cerned, these colors are quite as efficient as annatto. 

Appearance of Artificially Colored Milk. — The natural yellow color 
of milk confines itself largely to the cream. An artificial color, on the 
contrary, is dissipated through the whole body of the milk, so that when 
the cream has risen in a milk thus colored, the underlying layers, instead 
of showing the familiar bluish tint of skimmed milk, are still distinctly 
tinged below the layer of the fat, especially if any considerable quantity 
of the color has been used. This distinctive appearance is in itself often 

* In one instance an azo-dye was found by the writer in a milk that contained over 
17% of total solids. 



160 FOOD INSPECTION AND ANALYSIS. 

sufficient to direct the attention of the analyst to an artificially colored 
milk, in the course of handling a large number of samples. 

Nature of Annatto. — Annatto, amatto, or annotto is a reddish-yellow 
coloring matter, derived from the pulp inclosing the seeds of the Bixa 
orellana, a shrub indigenous to South America and the West Indies. 

A solution of the coloring matter in weak alkali is the form usually 
employed in milk. 

Nature of "Anilin Orange." — Of the coal-tar colors employed for 
coloring milk, the azo-dyes are best adapted for this purpose and are 
most used. A few samples of these commercial "milk improvers" have 
fallen into the hands of the Department of Food and Drug Inspection 
of the Massachusetts Board of Health, and have proved, on examination, 
to be mixtures of two or more members of the diazo-compounds of anilin. 
A mixture of what is known to the trade as "Orange G" and "Fast Yel- 
low" gives a color which is practically identical with one of these prep- 
arations, secured from a milk-dealer and formerly used by him. 

For purposes of prosecution or otherwise, it is obviously best in our 
present knowledge of the subject to adopt a generic name such as "a 
coal-tar dye" or "anilin orange"* to designate this class of coloring 
matters in milk, rather than to particularize. 

Systematic Examination of Milk for Color. — The general scheme 
employed by the writer for the examination of milk samples suspected 
of being colored is as follows:! About 150 cc. of the milk are curdled by 
the aid of heat and acetic acid, preferably in a porcelain casserole over 
a Bunsen flame. By the aid of a stirring-rod, the curd can nearly always 
be gathered into one mass, which is much the easiest method of separa- 
tion, the whey being simply poured off. If, however, the curd is too 
finely divided in the whey, the separation is effected by straining through 
a sieve or colander. All of the annatto, or of the coal-tar dye present 
in the milk treated would be found in the curd, and part of the caramel. 
The curd, pressed free from adhering liquid, is picked apart, if necessary, 
and shaken with ether in a corked flask, in which it is allowed to soak 
for several hours, or until the fat has been extracted, and with it the 
annatto. If the milk is uncolored, or has been colored with annatto, 
on pouring off the ether the curd should be left perfectly white. If, on 

* The term "anilin orange" has been so commonly applied during Leach's experience 
to any color or mixture of colors of this class in complaints in the Massachusetts courts, aa 
to have acquired a special meaning perfectly well understood. 

t Jour. Am. Chem. Soc, 22, 1900, p. 207. 



MILK AND ITS PRODUCTS. 161 

the other hand, anilin orange or caramel has been used, after pouring 
off the ether the curd will be colored more or less deeply, depending on 
the amount of color employed. In other words, of the three colors, 
annatto, caramel, and anilin orange, the annatto only is extracted by 
ether. If caramel has been used, the curd will have a brown color at 
this stage; if anilin orange, the color of the curd will be a more or less 
bright orange. 

Tests for Annatto. — ^The ether extract, containing the fat and the 
annatto, if present, is evaporated on the water-bath, the residue is made 
alkaline with sodium hydroxide, and poured upon a small, wet filter, 
which will hold back the fat, and, as the filtrate passes through, will allow 
the annatto, if present, to permeate the pores of the fiher. On washing 
off the fat gently under the water-tap, all the annatto of the milk used 
for the test will be found to have been concentrated on the filter, giving 
it an orange color, tolerably permanent and varying in depth with the 
amount of annatto present. As a confirmatory test for annatto, stan- 
nous chloride may afterward be applied to the colored filter, producing 
the characteristic pink color. 

Tests for Caramel. — The fat-freed curd, if colored after the ether 
has been poured off, is examined further for caramel or anihn orange, 
by placing a portion of the curd in a test-tube, and shaking vigorously 
with concentrated hydrochloric acid. If the color is caramel, the acid 
solution of the colored curd will gradually turn a deep blue on shaking, 
as would also the white fat-free curd of an uncolored milk, the blue colora- 
tion being formed in a very few minutes, if the fat has been thoroughly 
extracted from the curd; indeed, it seems to be absolutely essential for 
the prompt formation of the blue color in the acid solution that the curd 
be free from fat. Gentle heat will hasten the reaction. It should be noted 
that it is only when the blue coloration of the acid occurs in connection 
with a colored curd that caramel is to be suspected, and if much caramel 
be present, the coloration of the acid solution will be a brownish blue. If 
the above treatment indicates caramel, it would be well to confirm its 
presence, by testing a separate portion of the milk in the following manner.* 

About a gill of the milk is curdled by adding to it as much strong 
alcohol. The whey is filtered off, and a small quantity of subacetate of 
lead is added to it.. The precipitate thus produced is collected ui>on a 
small filter, which is then dried in a place free from hydrogen sulphide. 
A pure milk thus treated yields upon the filter-paper a residue which is 

* See Nineteenth Annual Report of the Mass. State Board of Health (1887), p. 183. 



162 



FOOD INSPECTION AND ANALYSIS. 



either wholly white, or at most of a pale straw color, while in the presence 
of caramel, the residue is a more or less dark-brown color, according to the 
amount of caramel used. 

Tests for Coal-tar Dye. — If the milk has been colored with an azo-dye, 
the colored curd, on applying the strong hydrochloric acid in the test-tube, 
will immediately turn pink. If a large amount of the anihn dye has been 
used in the milk, the curd will sometimes show the pink coloration when 
hydrochloric acid is applied directly to it, before treatment with ether, 
but the color reaction with the fat-free curd is very dehcate and unmistak- 
able.* 

Lythgoe^ has shown that the amount of anihn orange ordinarily 
present in a milk for the purposes of coloring can be detected by adding 
directly to say lo cc. of the sample an equal quantity of strong hydro- 
chloric acid and mixing, whereupon the pink coloration is produced, if 
the dye is present in more than minute traces. The test is more deli- 
cate if carried out in a white porcelain dish. It had best be used as a 
prehminary test only, and confirmed by a subsequent test on the fat-free 
curd as above. 

SUMMARY OF SCHEME FOR COLOR ANALYSIS. 

Curdle 150 cc. milk in casserole with heat and acetic acid. Gather curd in one mass. 
Pour off whey, or strain, if curd is finely divided. Macerate curd with ether in corked flask. 
Pour off ether. 



Ether Extract. 

Evaporate off ether, treat residue with 
NaOH and pour on wetted filter. After 
the solution has passed through, wash off 
fat and dry filter, which if colored orange, 
indicates presence of annatto. (Confirm 
by SnClj.) 



Extracted Curd. 

(i) // Colorless. — Indicates presence of 
no foreign color other than in ether extract. 

(2) // Orange or Brownish. — Indicates 
presence of anilin orange or caramel. 
Shake curd in test-tube with concentrated 
hydrochloric acid. 



If solution gradu- 
ally turns blue, in- 
dicative of caramel. 
(Confirm by testing 
for caramel in whey 
of original milk.) 



If orange curd im- 
mediately turns pink, 
indicative of anilin 
orange. 



PRESERVATIVES. — In most states and municipahties where pure food 
laws are in force preservatives in milk are regarded as adulterants 

* Occasional samples of milk colored with a coal-tar dye of a different class from those 
already described have recently been found in Massachusetts. In these cases the color 
of the separated fat-free curd does not change when treated with hydrochloric acid. The 
color of the curd is, however, very marked, being deep orange, bordering on the pink. 

t Jour. Am. Chem. Soc, 22, 1900, p. 813. 



MILK AND ITS PRODUCTS. 163 

Their use, however, seems to be on the decrease. Of 6,i86 samples of milk 
examined by the Massachusetts State Board of Heahh during one year 
(1899) 71 samples, or 1.2%, were found to contain a preservative. Of 
these 55 were found with formaldehyde, 13 containing boric acid, borax,' 
or a mixture of the two, and 3 contained carbonate of soda. 

Comparative tests were made of the keeping equalities of these com- 
mon preservatives, the milk being kept during the experiment at the 
temperature of the room, which at that season of the year (February) 
was about 20° C* The preservatives were added about five hours after 
milking. The samples were titrated for acidity each morning, the acidity 
being expressed by the number of cubic centimeters of decinormal sodium 
hydroxide necessary to neutralize 5 cc. of the milk. 

The proportions of preservatives used in this experiment, as shown in 
the table on page 164, were intended to cover a wide range, from the 
weakest that could aid in preserving the milk up to a strength limited 
only by being perceptible to the taste. The results obtained appear in 
the table. 

Formaldehyde, the most commonly used preservative for milk, is sold to 
the trade under various names, such as "Preservaline," "Freezine," "Ice- 
line," etc., all being dilute aqueous solutions of formaldehyde, containing 
from 2 to 6 per cent of the gas, being nearly always diluted from the 40% 
solution known as formahn. These preparations are usually accompanied 
by directions, which specify the amount to be used, varying from a table- 
spoonful of the solution in 5 to 10 gallons of the milk. It is commonly 
used in the strength of i part of the gas in 20,000, and rarely less than 
I part in 50,000. The antiseptic power of formaldehyde increases in a 
marked degree as the strength of the preservative is increased. Milk 
treated with i part in 10,000, for instance, according to the table was 
found to keep sweet 5I days. In the strength of i part to 5000, the milk 
did not curdle for loj days, while i part of formaldehyde to 2500 parts of 
milk kept the milk from curdling for 55 days, the acidity up to that time 
being nearly normal. 

Formaldehyde is thus shown to be decidedly the most cflEiclent of all 
milk preservatives, besides being inexpensive and convenient to use. 

Whether the growth of other bacteria than those that produce lactic 
fermentation is inhibited by formaldehyde in milk is not definitely settled. 
The claim has been made that pathogenic varieties are destroyed by its use. 

* Thirty-first Annual Report Mass. State Board of Health, 1899, p. 611. 



164 



FOOD INSPECTION AND ANALYSIS. 







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MILK AND ITS PRODUCTS. 165 

Notwithstanding the claims of manufacturers as to the harmlessness 
of formaldehyde, its use can not be too strongly condemned.* 

Detection of Formaldehyde. — Leach Test.-f — Hydrochloric acid (spe- 
cific gravity 1.2) containing 2 cc. of 10% ferric chloride per liter is used 
as a reagent. Add 10 cc. of the acid reagent to an equal volume of milk 
in a porcelain casserole, and heat slowly over the free flame nearly to 
boiling, holding the casserole by the handle, and giving it a rotary motion 
while heating to break up the curd. The presence of formaldehyde is 
indicated by a violet coloration, varying in depth with the amount present. 
In the absence of formaldehyde, the solution slowly turns brown. By 
this test I part of formaldehyde in 250,000 parts of milk is readily de- 
tected before the milk sours. After souring, the limit of delicacy proves 
to be about i part in 50,000. 

Various aldehydes, when introduced into milk, give color reactions 
under the above treatment, but formaldehyde alone gives the violet colora- 
tion, which is perfectly distinguishable and unmistakable. 

Heh?ier Test.X — To 5 to 10 cc. of milk in a wide test-tube add about 
half the volume of concentrated commercial sulphuric acid,§ pouring the 
acid carefully down the side of the tube, so that it forms a layer at the 
bottom without mixing with the milk. A violet zone at the junction of 
the two liquids indicates formaldehyde. This test may be combined 
with the Babcock test for fat, noting whether a violet color forms on 
addition of the commercial sulphuric acid to the milk in the test bottle. 

Tests with Distilled Milk. — To confirm the above test, distil ico cc. 
of the milk sample acidified with citric or sulphuric acid, and test the 
first 20 cc. of the distillate as described in Chapter XVIII. 

The Determination of Formaldehyde in Milk is unsatisfactory since 
it gradually disappears, as shown by Williams and Sherman, || owing 

* Milk-dealers are led to believe, by artful dealers in preservative preparations, that the 
chemist cannot detect them. The manufacturer of a widely used preservative, a weak solu- 
tion of formaldehyde, issued an attractive pamphlet in which he made the following remark- 
able claims: 

"It is not an adulterant. It immediately evaporates, so that no trace of it can be found 
as soon as it has rendered all the bacteria inert. No chemical analysis can prove its pres- 
ence in milk, quantitatively or otherwise." 

t Annual Report Mass. State Board of Health, 1897, p. 558; also 1899, P- 699. 

t Analyst, 20, 1895, p. 155. 

§ The coloration produced seems to depend on the presence of iron salts in the acid, 
hence the use of commercial acid is recommended. If only pure acid is available, a little 
ferric chloride should be added. 

II Jour. Am. Chem. Soc, 27, 1905, p. 497. 



166 FOOD INSPECTION AND ANALYSIS. 

to the formation of condensation products with the proteins. According 
to Smith,* the first 20 cc. of the distillate contain nearly one-third of the 
total formaldehyde then present. In some cases it may be useful to de- 
termine the amount present in this distillate by the potassium cyanide 
method (p. 883). 

Boric Acid, either in the form of the free acid or of the sodium salt 
borax, has been much used in milk. While its addition to butter is legalized 
in England, food authorities in all countries are generally agreed that its 
use in milk is highly objectionable. 

Detection of Boric Acid. — This is best accomplished by the turmeric- 
paper test applied either directly to the milk or to the ash (p. 885). In 
the former case 10 cc. of milk are thoroughly mixed with 6 drops of con- 
centrated hydrochloric acid, after which the turmeric paper, previously 
marked for identification with a lead pencil, is moistened with the mix- 
ture and dried. Bertrand and Agulhon j find by their spectroscopic 
method 0.5-1. 11 mg. of boron as hydroxide per liter of milk to which 
nothing has been added. This amount is not evident by ordinary tests. 

Determination of Boric Acid.— The Gooch method (p. 887) or the 
Thompson method (p. 886) may be used. 

Richardson and Walton J propose the following rapid method, which 
is stated to be more accurate than the Thompson method, since it obvi- 
ates the loss of boric acid by volatilization with the fat. While other 
authors, including the author and reviser, have not found this loss con- 
siderable if the ignition is properly conducted, the proposed inethod rec- 
ommends itself because of its simplicity. To 50 cc. of milk, or 10 grams 
of cream diluted with 40 cc. of water, add 5 cc. of 5% copper sulphate 
solution, stir, heat to boiling for a few seconds, filter, and wash the pre- 
cipitate containing the proteins and fat. Cool the filtrate and determine 
the boric acid by tritration, using 2 cc. of 1% neutral phenolphthalein 
solution as indicator. 

Carbonate and Bicarbonate of Soda. — These substances are occa- 
sionally used in milk, though, as the table on p. 164 shows, they possess 
little or no value as milk preservatives. They do, however, serve to 
neutralize the acidity of slightly soured milk and to postpone the time 
of actual curdling. 

* Jour. Am. Chem. Soc, 25, 1903, pp. 1032, 1037. 
t Compt. rend., 156, 1913, p. 2027. 
t Analyst, 38, 1913, p. 40. 



MILK AND ITS PRODUCTS. 167 

Detection of Carbonate and Bicarbonate of Soda. — The addition 
of carbonates is manifest by the effervescence caused by treating the 
milk-ash with acid. Effervescence in the milk-ash is quite perceptible, 
when as much as 0.05% of sodium carbonate is present. 

Schmidt's method of detecting sodium carbonate or bicarbonate, 
when present to the extent of 0.1% or more, is as follows: Ten cc. of 
milk are mixed with an equal volume of alcohol, and a few drops of a 
1% solution of rosolic acid are added. If carbonate is present, a rose- 
red color will be produced, while pure milk shows a brownish-yellow 
coloration. The suspected sample thus treated should be compared 
with a similarly treated sample of pure milk at the same time. 

Salicylic and Benzoic Acids, in view of the much more efficient anti- 
septics at hand, are now rarely used as milk preservatives, though the 
analyst should be on the outlook for them. SaHcylic acid is a poor milk 
preservative, in view of the fact that it affects the taste of the milk, when 
present in sufficient quantity, to be of service. 

Detection of Salicylic Acid.— (i) To 50 cc. of the milk add i cc. of 
acid nitrate of mercury reagent (p. 134), shake and filter. The filtrate, 
which should be perfectly clear, is then shaken with ether in a separatory 
funnel, the ether extract evaporated to dryness, and a drop of ferric chloride 
reagent applied. If salicylic acid be present, a violet color will be pro- 
duced. In carrying out the test it should be noted that a small portion 
only of the salicylic acid is in the filtered whey, the larger part being left 
in the curd. The color test is, however, so delicate as to show its pres- 
ence, when an appreciable amount is used. 

(2) Proceed exactly as directed for benzoic acid (below). On apply- 
ing the ferric chloride to the final solution, after evaporation of the am- 
monia, a violet color shows the presence of salicylic acid. 

Detection of Benzoic Acid. — Shake 5 cc. of hydrochloric acid with 
50 cc. of the milk in a flask. Then add 150 cc. of ether, cork the flask 
and shake well. Break up the emulsion which forms by the aid of a 
centrifuge, or, in the absence of a centrifuge, extract the curdled milk 
by gently shaking with successive portions of ether, avoiding the forma- 
tion of an emulsion. A volume of ether largely in excess over that of 
the curdled milk has been found to be less apt to emulsionize. Transfer 
the ether extract to a separatory funnel, and separate the benzoic acid 
from the fat by shaking out with dilute ammonia, which takes out the 
former as ammonium benzoate. Evaporate the ammonia solution in 



168 FOOD INSPECTION AND ANALYSIS. 

a dish over the water-bath until aeutral to test paper and add a few drops 
of neutral ferric chloride reagent (page 891). 

Revis Me//w(/.*— Dilute 100 cc. of milk or 50 cc. of cream to 200 cc, 
add 5 cc. of 10% sodium carbonate solution, place on a boiling water bath, 
and after 2 to 3 minutes add 10 cc. of 2J% calcium chloride solution and 
continue the heating until the casein is coagulated. Cool, filter, add hydro- 
chloric acid to the filtrate until neutral to litmus, then 10 cc. of Fehling 
copper sulphate solution and 10 cc. of potassium hydroxide solution (31.81 
grams per liter). Filter, acidify the filtrate with hydrochloric acid, extract 
with 50 cc. of ether, and wash the ether three times with water. Without 
removing from the separatory funnel add to the ether 10 cc. of water, 
I drop of phenol phthalein solution, and titrate with saturated barium 
hydroxide solution until a pink color persists after vigorously shaking. 
Remove the aqueous layer, filter, and evaporate to about 5 cc. Filter 
again, add 1% acetic acid until colorless, then 2 drops additional and 
test with I drop of freshly prepared 10% neutral ferric chloride solution 
as described on page 891. 

Rohin Method.-\ — Add 50 cc. of milk slowly with stirring to a mixture 
of 10 cc. of 5% sulphuric acid and 20 cc. of 95% alcohol, filter after 4 to 5 
minutes, extract with ether, and proceed as described on page 891. 
Determination of Benzoic Acid in Milk. — See pages 893 to 896. 
Liverseege and Evers Method.X—T>\'=,i\\ a mixture of 100 cc. of milk 
and ID cc. of concentrated sulphuric acid in a current of steam until 600 cc. 
have condensed. Acidulate the distillate with 5 cc. of concentrated 
hydrochloric acid, extract with 100 cc. and two portions of 35 cc. of ether, 
allow the extract to evaporate at room temperature in a tared dish, dry, 
weigh, deduct 5 milligrams (or a quantity found by blank experiment) 
from the total weight, and calculate the percentage of benzoic acid by a 
factor which should be determined by each analyst for the apparatus 
employed. In the apparatus used by the originators of the method about 
45% of the total amount was recovered. 

Hydrogen Peroxide is used in " perhydrase " or " Buddized " milk. 
Detection of Hydrogen Peroxide. — Arnold and Mentzel Vanadic Acid 
Method.% — To 10 cc. of the milk add 10 drops of a solution of i gram of 
vanadic acid in 100 grams of dilute sulphuric acid. The presence of hydro- 

* Analyst, 37, 191 2, p. 346. 
t Ann. chim. anal, appl., 14, 1909, pp. 2, 53. 
t Jour. Soc. Chem. Ind., 32, 1913, p. 319. 
§ Chem. Ztg., 26, 1902, p. 589. 



MILK AND ITS PRODUCTS. 169 

gen peroxide is shown by the appearance of a red color. Utz * states that 
the reaction is obtained whether or not the milk has been heated previous 
to adding the peroxide. 

Peroxidase Methods. — Several of the methods for detecting peroxidase 
(pp. 173 and 174), notably the paraphenylenediamine (Dupouy), the 
benzidine (Wilkinson and Peters), and the iodide-starch (Roi and Kohler) 
methods, can be reversed for the detection of hydrogen peroxide. The 
tests are conducted as described except that the hydrogen peroxide is 
omitted and, since the peroxidase may have been destroyed by hydrogen 
peroxide or by heating, it is usually necessary to add raw mJlk of 
known purity. La Wallf in performing the Wilkinson and Peters test first 
coagulates a mixture of 10 cc. of raw milk and 2 cc. of 4% alcoholic ben- 
zidine with 2 to 3 drops of glacial acetic acid, then adds a few cubic centi- 
meters of the suspected sample. A blue zone is formed when from 1.5 
to 30 parts of hydrogen peroxide per 10,000 are present. 

Hehner-Feder Formaldehyde Method. % — This is the Hehner method 
for formaldehyde reversed and slightly modified. Mix 5 cc. of the milk 
with 5 cc. of concentrated hydrochloric acid and a drop of dilute formalde- 
hyde solution, then heat at 60° C. for 3 to 4 minutes and shake once. 
If a violet color develops hydrogen peroxide is indicated. Wilkinson and 
Peters § have shown that the reaction is most decisive when about 0.005% 
of hydrogen peroxide and 0.004 to 0.013% of formaldehyde are present; 
with other proportions it may fail. Ferric salts, nitrites, and possibly 
nitrates also give a \'iolct color. 

Routine Inspection of Milk for Preservatives. — It was Leach's custom 
in Massachusetts to examine all the samples of milk collected during the 
months of June, July, August, and September for the commonly used 
preservatives, in addition to the regular analysis for total solids and fat. 
The number of samples thus examined amounted to upwards of 500 per 
month, varying from 10 to 60 per day. The results of such an examina- 
tion during four years are shown on p. 170. || 

Such a system by no means involves a large amount of time or labor, 
and is really essential before passing judgment upon the purity of the 
milk, since, unlike added color, there is nothing in the physical appear- 

* Milchw. Zentbl., i, 1905, p. 175. 

t Am. Jour. Pharm., 82, 1908, p. 57. 

t Zeitz. Unters. Nahr. Genussm., 15, 1908, p. 234. 

%Ihid., 16, 1908, p. 515. 

II Mass. State Bd. Health, Rep., 1902, p. 474. 



170 



FOOD INSPECTION AND ANALYSIS. 



ance of the milk to suggest the presence of preservatives, nor are they 
rendered apparent by the taste, if skillfully used. 



PRESERVATIVES IN MILK. 



Year. 



Samples 
Examined. 



Number 
Containmg 

Form- 
aldehyde. 



Per Cent 
Containing 

Form- 
aldehyde. 



Number 

Containing 

Boric 

Acid. 



Per Cent 

Containing 

Boric 

Acid. 



Number 
Containing 
Carbonate. 



Total 
Containing 
Preserva- 



1899 

1900 

1901 

1902 

Totals 



1046 
2105 
2018 
2154 
1934 



26 

55 
61 
42 
29 



2-5 

2.6 

30 
1.9 

1-5 



II 

13 

6 

12 

14 



1 .0 
0.6 
03 
0.5 
0.7 



9257 



213 



2-3 



56 



0.6 



41 
71 
67 
54 
43 



376 



The methods employed are carried out as follows: * 
(i) Formaldehyde. — After ha\ing been examined for total solids 
and fat, the milk samples are arranged in order in their original con- 
tainers, and about 10 cc. of each sample are poured into a casserole and 
tested in succession by means of the hydrochloric acid and ferric chloride 
test (p. 165). A large stock bottle, which may be fitted with a siphon 
if desired, is kept on hand containing the hydrochloric acid reagent. 
Less than one minute is required in making the formaldehyde test for 
each sample. 

(2) Carbonate and Boric Acid. — These tests have been so simplified 
as to be, as it were, a side issue in the process of cleaning the platinum 
dishes used for the determination of total solids. The various residues 
from the total solids are burnt to an ash in the original numbered dishes 
in succession, these dishes, after incineration, being arranged side by side 
on a flat tray. By means of a pipette, one or two drops of dilute hydro- 
chloric acid are introduced into each dish in succession, noting at the 
time any effervescence that may ensue, which is in itself an indication 
01 sodium carbonate. After every milk ash has been acidulated, a few 
cubic centimeters of water are added to each dish by means of a wash- 
bottle, the dissolving of the ash being hastened by giving a rotary motion 
to the tray containing the dishes. A strip of turmeric-paper is then allowed 
to soak for a minute or so in each dish, after which it is withdrawn from 



Mass. State Bd. Health, Rep., 1901, p. 447. 



MILK AND ITS PRODUCTS. 171 

contact with the solution and allowed to adhere to the side of the dish 
above the liquid, where it remains until dry. If the paper when dry 
is of a deep cherry-red color, turning a dark olive when treated with 
dilute alkali, the presence of boric acid is assured. These methods 
are, of course, preliminary tests for quickly singling out the preserved 
samples. Such confirmatory tests as are desired may in all cases be 
employed. 

Various Adulterants.— Cane Sugar is said to be used to increase 
the total solids of milk, but if present to any marked degree, it could 
hardly fail of detection by reason of the sweet taste imparted to the milk. 
Cane sugar in milk may be detected * by boiling 5 to 10 cc. of the sample 
with about o.i gram of resorcin and a few drops of hydrochloric acid for 
a few minutes. In the presence of cane sugar, a rose-red color is pro- 
duced. 

According to Richmond, cane sugar may be estimated by first ascer- 
taining the total polarization of the sample as in the estimation of milk 
sugar (p. 134). The milk sugar is then determined by Fehling's solution 
(pp. 136 to 138) either volumetrically or gravimetrically. The difference 
between the anhydrous milk sugar found by the latter, or Fehling method, 
and that calculated by dividing the polarization by 1.217 will give the 
percentage of cane sugar present. 

Cotton's method f of detecting cane sugar, when present to the extent 
of 0.1% consists in mixing in a test-tube 10 cc. of the suspected milk 
with 0.5 gram of powdered ammonium molybdate, and adding to the 
mixture 10 cc. of dilute hydrochloric acid (i to 10). Ten cc. of milk of 
known purity, or 10 cc. of a 6% solution of milk sugar are similarly treated 
by way of comparison. Both tubes are placed in a water-bath and the 
temperature gradually raised to 80° C. If cane sugar is present, an 
intense blue coloration is produced, while the genuine milk or the 
solution of milk sugar remains unchanged at the temperature of 80°. 
If the temperature is raised to the boiling-point, however, the pure milk 
or milk sugar solution may alsc turn blue. 

Detection of Starch in Milk.— A small quantity of milk is heated in 
a test-tube to boiling, cooled, and a drop of iodine in potassium iodide 
added. A blue coloration indicates starch. 

Condensed Skimmed Milk as an Adulterant. — The use of condensed 
unsweetened skimmed milk to raise the solids of a skimmed or watered 

* Woodman and Norton, Air, Water, and Food, New York, 1914, p. 151. 
t Abs. Analyst, 23, 1898, p. 37, - 



172 FOOD INSPECTION AND ANALYSIS. 

milk above the standard has been noted in Massachusetts. This sophis- 
tication is rendered apparent by the abnormally high solids not fat of 
the sample, which in some instances have exceeded ii%. A solid not fat 
in excess of io% is suspicious of this form of adulteration. By fixing a 
legal standard for both fat and solids not fat, such tampering with milk 
may readily be checked. 

Analysis of Sour Milk. — It occasionally becomes necessary for the 
analyst to deal with samples of sour milk, especially in the summer-time, 
when the milk has been brought from a long distance. While the process 
of lactic fermentation results in the formation of traces of volatile acids, 
unless the sample has become so badly curdled as to render an even homo- 
geneous mixture of the various parts impossible, a fair determination of 
the solids and fat can readily be made. Experience has proved that, 
excepting in instances of milk so badly soured as to have become actually 
putrid, the analysis of sour milk, if carefully made, should not differ 
materially from that of the same milk before souring. 

Care must be taken to secure an even emulsion of the curd and whey. 
This may sometimes be accomphshed by repeatedly pouring the sample 
back and forth from one container to another. Again, it is sometimes 
necessary to use an egg-beater of the spiral wire pattern, which preferably 
should easily fit the can or milk-container. Unless a fine, even emulsion 
can be secured, it is impossible to make a satisfactory analysis of sour 
milk. With such an emulsion restdts can be relied on. 

In measuring portions of the thoroughly mixed sample of sour milk 
for analysis, a pipette should be used having a large opening. 

HOMOGENIZED MILK. 

This product is prepared from ordinary milk by heating and then 
passing through the " homogenizer " whereby the fat globules are broken 
up into smaller globules and the creaming power reduced practically to nil. 
In the homogenizer the milk is forced, under a pressure varying up to 4000 
pounds or more per square inch, into fine jets or sheets which impinge 
either against each other or against an agate surface thus disrupting the 
globules. These in normal milk often exceed lo/x and are mostly 5 to 6/i 
while in well-homogenized milk they are mostly only i to 2/x.* 

The machine is also used to emulsify olco, cottonseed, and other oils 
and low melting-point fats with skim milk thus furnishing a wholesome food 

* Baldwin, Am. Jour. Pub. Health, 6, 1916, p. 862. 



MILK AND ITS PRODUCTS. 173 

for calves, hogs, and even human beings, although the temptation to market 
the products dishonestly has not always been resisted. Homogenized 
mixtures have also been used in cream, condensed milk, and ice cream. 

Analysis of Homogenized Milk. — It has been demonstrated by Rich- 
mond * that the Adams paper coil method gives low percentages of fat 
with homogenized milk while the Rose-Gottlieb, Werner-Schmidt, and 
Gerber methods are satisfactory. Other constituents are determined as in 
ordinary milk. 

Distinctions from untreated milk are based on the size of the fat globules 
as above noted, also on physical constants, particularly the viscosity. 

PASTEURIZED MILK. 

The analyst may be called on to determine whether or not milk has 
been pasteurized to conform with municipal or state regulations. 

Detection of Peroxidase. — The following tests show whether the milk 
has been pasteurized at £0° C., or higher but, as found by Lythgoe,t are 
of no value when 63°, which is now deemed sufficient, is employed. 

Dupouy Paraphenylenediamin Method.X — Shake 5 cc. of the milk in 
a test tube with i drop of 0.2% hydrogen peroxide solution (containing 
I cc. of concentrated sulphuric acid per liter) and 2 drops of 2% paraphenyl- 
enediamin. If the milk becomes blue immediately it has not been heated 
to 78° C.; if it becomes gray-blue immediately or within half a minute 
it probably has been heated to 79-80°; while if it remains white or be- 
comes a faint violet-red it has been heated above 80°. 

Wilkinson and Peters Benzidine Method.^ — To 10 cc. of the milk 
add 2 cc. of a 4% alcoholic solution of benzidine and 2-3 drops of glacial 
acetic acid, or an amount just sufficient to coagulate the milk, and shake. 
Add cautiously to the mixture 2 cc. of 3% hydrogen peroxide solution, 
allowing the reagent to run down the sides of the test tube. With raw 
milk or milk heated below 78° C. an intense blue color appears at once; 
with milk heated at 80° or higher no color appears. 

Other Tests are the original Arnold guaiac test || and its modifications 
and the Roi and Kohler iodide-starch test.^ 

* Analyst, 31, 1906, p. 218. 
t Jour. Ind. Eng. Chem., 5, 1913, p. 922. 

X Dupouy, Rep. pharm. Ill, 9, 1897, p. 206; Storch, Copenhagen Exp. Sta. Rep., 1898. 
§ Jour. Dep. Agric, Victoria, 6, 1908, p. 251. 
I Jahr. Konig. Tierarz. Hochsch., 1880-1882, p. 161. 
\ Milch. Ztg., 31, 1902, pp. 17, 113. 



174 



FOOD INSPECTION AND ANALYSIS. 



Detection of Aldehyde Reducta.se.Schardinger Method.* — To 20 
cc. of the milk add i cc. of a reagent consisting of 5 cc. of a saturated al- 
coholic solution of methylene blue, 5 cc. of 40% formaldehyde, and 190 
cc. of water. Place in a water-bath kept at 45-50° C, and note the 
time required for decolorization. Lythgoe found that decolorization 
with raw milk took place in 5 minutes, while with milk pasteurized at 
63° for 35 minutes, kept not longer than 2 days, it did not take place in 
20 minutes. 

FERMENTED MILK. 

Yogurt is a Bulgarian product, prepared with a starter known as Maya, 
which, because of the longevity of the natives who subsist to a large degree 
on it, has come to be regarded as a kind of elixir of life. The souring of the 
milk is caused by Bacillus Bulgaricus which, like domestic yeast and butter 
starters, is perpetuated by primitive methods, although other bacteria 
take part in the changes. Cultures of the bacillus in tablet and liquid 
form are now on the American market with which the beverage commonly 
known as buttermilk is prepared either by the dairyman or the housewife 
from milk or skim milk. 

The characteristic constituent is lactic acid, both the dextro and 
levorotary forms, produced at the expense of a portion of the lactose. 

Other acid products, similar to yogurt, are Leben of Egypt, Gioddu of 
Sicily (Cieddu of Sardinia), Dadhi of India, and Tatte of Scandinavia. 

Kumiss is indigenous to Central Asia and the Steppes region of Russia 
where it is prepared from mare's, camel's, and ass's milk. The alcoholic 
fermentation is caused by a peculiar yeast that acts directly on the lactose, 
although bacteria also play a part. With us kumiss is a preparation of cow's 
milk used chiefly as a therapeutic food, the alcohol being commonly gen- 
erated by ordinary yeast acting on added glucose or sucrose. In addition 
to alcohol some lactic acid is also formed from the lactose, the proteins are 
more or less peptonized or otherwise acted on, butyric acid is liberated, and 
esters are formed. Dr. L. L. Van Slyke has kindly communicated the 
following as an average analysis of kumiss made from cow's milk : 



Total Solids. 


Lactose. 


Alcohol. 


Acidity. 


Total Nitrogen. Casein Nitrogen. 


11.00 


5.00 


1. 00 


0.30 


0.65 O.S5 



Alcoholic beverages similar to kumiss are Kefir prepared in the Cau- 
casus from cow's, sheep's, or goat's milk, using so-called " Kefir grains " 

* Zeits. Unters. Nahr. Genussm., 5, 1902, p. 1113. 



MILK AND ITS PRODUCTS. 175 

which bear much the same relation to the product as yeast cakes do to bread, 
and Mazun made in Armenia from sheep's, goat's, or buffalo's milk. 
Ginzberg * has studied the chemical changes which take place in the 
preparation of both kumiss and kefir, as well as their imitations. 

Analysis of Fermented Milks. — The sampling requires special care 
owing to the more or less curdled or granular condition. Lumps of curd 
may be rubbed through a sieve while lumps of fat, such as occur in butter- 
milk, may be strained out, weighed, and separately analyzed. In special 
cases the whole sample may be neutralized with ammonia, taking account 
of volumes. 

Total Solids, Total Protein, Casein, Albumin, Other Nitrogenous Con- 
stituents, Lactose, and Ash are determined by the methods described under 
milk with such minor modifications as the nature of the substance may 
require. For example the casein, already partially or completely pre- 
cipitated, requires only a small addition of acetic acid, if any. Again 
since lactose is present in only small amount, a correspondingly larger 
quantity of this milk may be polarized. 

Fat is best extracted by the Rose-Gottlieb method after neutralizing 
the free acid. Obviously ether extraction of the acid material whether or 
not evaporated to dryness would yield fat contaminated with lactic acid. 
Centrifugal methods should be employed only when checked against the 
standard method. 

Total Acids are titrated directly using phenolphthalein as indicator. 
Volatile Acids and Alcohol are distilled together and the former titrated; 
the slightly alkaline liquid is then redistilled and the alcohol determined. 

CONDENSED MILK. 

Canned condensed milk has become a very important article of food, 
its use having increased greatly during recent years. The universally 
accepted meaning of the term " condensed milk " in the United States 
is milk both condensed and preserved with cane sugar, being what is 
commonly known in England as " preserved milk." The unsweet- 
ened variety is termed " evaporated milk " and sold as such. 

Condensed Milk, or more properly sweetened condensed milk, is 
prepared by adding cane sugar to whole milk, usually with previous pas- 
teurization, and evaporating in a special form of vacuum pan to a thick 
consistency. A considerable quantity is sold to large consumers in bulk, 

* Biochem. Zeits., 30, 1910, pp. i, 25. 



176 



FOOD INSPECTION AND ANALYSIS. 



in which form it keeps indefinitely by reason of the large percentage of sugar, 
but for domestic use it is commonly packed in hermetically sealed cans. 

Composition. — Various standards committees agree in placing 28% 
of milk solids and 8% of fat as the minimum limits. As Hunziker has noted 
manufacturers are not likely to allow their products to drop below 28% 
of milk solids as that percentage is essential for holding the sugar in sus- 
pension without which the product would not be readily marketable. Not 
infrequently, however, the percentage of fat falls below 8% indicating that 
skim milk or an abnormally poor product was used. As at no time during 
the process the heating is carried on at a high temperature, the evapora- 
tion may be continued until the percentage of milk solids is raised to con- 
siderably over 30% without danger of curdling. 

Upward of 350 samples, representing 110 brands, were analyzed in 
full by the Massachusetts State Board of Health in the course of eight 
years. As some of the samples were obviously prepared from partially or 
wholly skimmed milk, maximum, minimum, and average figures have no 
significance in judging the composition of the genuine product, but the 
selected analyses of a few typical brands given in the following table are 
instructive : 



COMPOSITION OF SWEETENED CONDENSED MILK. 



Points to be Noted. 



High in fat, much added 

sugar 

High fat, low milk sugar. . . 
Low fat, high milk sugar, 

low proteins 

Normal constituents 

throughout 

Condensed from skimmed 

milk .. ■ ■ ■ 

Condensed from centrifu- 

gally skimmed milk 



Total 
Solids, 

Per 
Cent. 



79.17 
68.70 

69.30 

74-29 

69.30 

69.06 



Water 

Per 

Cent. 



20.83 
32.30 

30.70 

25 71 

30.70 

30.94 



Milk 
Solids, 

Per 
Cent. 



Cane 

Sugar, 

Per 

Cent. 



47.85 
38.43 

37.47 

41.92 

40.15 

43.18 



Lac- 
tose, 
Per 
Cent. 



9.57 
6.38 



16.75 
11.97 



Pro- 
teins, 

Per 
Cent. 



7.95 
10.70 

6.34 

8.46 
12. IS 
11.78 



Fat, 
Per 

Cent. 



12.00 
11.46 

7.20 

10.65 

3 06 

0.09 



Ash, 

Per 

Cent. 



1.73 
1.54 
1 .29 
2.05 
2.46 



Fat in 

Origi- 
nal 

Milk, 
Per 

Cent. 



4.60 
5.63 

2.77 

456 

I . II 

Trace 



Evaporated Milk, or unsweetened condensed milk, formerly erroneously 
branded evaporated cream, differs from the sweetened variety in that it 
does not contain added sugar and therefore must be marketed in sterilized 
form if not required for immediate use. 

Formerly 28% of milk solids containing at least 27.5% of fat was 
requu-ed but careful investigations by Patrick, Hunziker, and others showed 
that it was impracticable to comply with this standard in all regions and at 
all seasons, without the milk curdling. At present 25.5% of solids and 



MILK AND ITS PRODUCTS. 



177 



7.8% of fat (the latter percentage being of the evaporated milk and not of 
the milk solids) are recognized as the minimum limits regardless of con- 
ditions. 

Mohan * states that swells, flat sours, and sweet curdling are due to 
understerilization, while other forms of curdling are due to the action of 
heat on milk with high solids and acidity, and the hard granules sometimes 
found at the bottom of cans, chiefly to calcium phosphate precipitated by 
over evaporation. 

Composition. — The following typical analyses made at the Massachu- 
setts State Board of Health are selected from about 30 representing 8 brands: 



COMPOSITION OF UNSWEETENED CONDENSED MILK. 



Points to be Noted. 



Total 

Solids, 

Per 

Cent. 



Water, 

Per 

Cent. 



Lac- 
tose, 
Per 

Cent. 



Pro- 
teins, 

Per 
Cent. 



Fat, 

Per 

Cent. 



Ash, 
Per 

Cent. 



Fat in 

Original 

Milk, 

Per 

Cent. 



No. of 
Times 
Con- 
densed. 



High in fat 

Low in proteins 

Normal constituents throughout. 
Condensed from skimmed milk. . 



36.00 
3125 
28.16 
35. 17 



64.00 
86.75 
69. 24 
64-83 



10.65 
13.40 
9.8s 
13-90 



11.63 
7 .02 
8.66 

15-37 



12.00 
9.60 



1.72 
1-23 
I 55 
1.70 



4.61 
4.18 
3-68 



A summary of analyses of 12 brands found on sale in the State of 
Maine during the year 19 16 follow :f 





Water. 


Fat. 


Lactose. 


Protein. 


Ash. 


Maximum 

Minimum 

Average 


75-93 
72.02 

73-35 


8.84 
7.62 
8.13 


11-45 

9-13 

10.31 


7.17 
5-71 
6.69 


1. 65 
1-34 
1-52 





McGill { gives in the table on page 178 the averages of results obtained 
during the years 19 10 and 19 15 on 16 brands collected in Canada: 

Adulteration. — Aside from such foreign substances as may be present 
in the original milk without the knowledge of the manufacturer, such as 
preservatives and colors, the only common form of adulteration is the use of 
skim milk, although homogenized foreign fats are sometimes used to make 
up for the deficiency. Watering, as it entails greater labor in evaporation, 
would not be practiced by the manufacturer. If the milk furnished him is 
watered the defect is corrected by evaporation. 

* Jour. See. Chem. Ind., 34, 1915, p. 109. 

t Maine Agr. E.xp. Sta., Off. Ins., p. 76. 

% Lab. Inl. Rev. Dept. Canada, Buls. 208 and 305. 



178 



FOOD INSPECTION AND ANALYSIS. 





I910. 


' 




1915. 




Number of 
. Samples. 


Solids. 


Fat. 


Number of 
Samples. 


Solids. 


Fat. 


3 
8 

2 

I 
I 


25.29 
29.02 
23.86 
30.20 
22.04 


5-92 
7-52 
6.74 
8.12 
5-64 


6 

30 

3 

I 

2 
12 

31 

2 
6 
2 
I 
60 
19 
3 


22.63 
26.52 
25-72 
22.35 

25-53 
27.14 

26. II 

25-39 
26.08 
27.25 
21.92 
26.54 
25-55 
23-47 


6.74 

7-51 
7.19 
6.48 

6.62 


II 

I 

6 


27.47 
24.64 
26.97 


7.27 
6.00 
6.70 


7.67 

7.21 

6-39 
7.00 














7-45 








6.21 


12 


26.64 


6.94 


7-44 
6.87 








0. 26 











ANALYSIS OF CONDENSED MILK. 

Preparation of the Sample. — Mix the sample thoroughly, best by 
transferring the entire contents of the can to a large evaporating dish and 
working it thoroughly with a pestle till homogeneous throughout. Weigh 
40 grams of the mixed sample, preferably in a tared weighing-tray for 
sugar analysis, transfer by washing to a graduated loo-cc. sugar flask, 
and make up to the mark with water. 

Another method * is to weigh the can and contents together, remove 
the contents to a liter flask with tepid water, dry the can, and subtract 
its weight from that previously obtained. As the weight of the contents 
varies this method involves more calculation. 

Determination of Total Solids. — Gravimetric Method. — Dilute an aliquot 
part of the mixed solution further with an equal amount of water and 
pipette 5 cc. of the diluted mixture, corresponding to i gram of the sample, 
into a tared platinum dish, such as is used for ordinary milk, and rinse the 
pipette into the dish by means of a wash-bottle. Evaporate, dry at the 
temperature of boiling water and weigh as in the case of milk (p. 119). 

The character of the residue should be noted. It should not, excepting 
in the case of a skimmed milk, be caked down hard and glossy on the 



Conn. Agric. Exp. Sta. Rep. 1904, p. 133. 



MILK AND ITS PRODUCTS. 179 

bottom of the dish, but, if the operation is properly carried out, should 
have a well-separated fat layer at the top, and the residue should resemble 
in appearance that from ordinary milk. This result is accomplished by 
the extreme dilution of the sample. 

Calculation Methods for Evaporated Milk. — Hunziker's formula * is 
as follows : 



T= 



( — ^^^^^ ) X 1 ,000 - 1 ,000 X i -t- 1 . 2 X/, 



in which B is the Baume reading at 60° F. and/ the per cent of fat. The 
hydrometer reading is calculated to 60° F. by adding 0.0313 for every degree 
over that temperature. 

Evenson's modification f of the Babcock formula follows: 

r=^i:^+i.2x/, 
4 

in which T is the total solids, L the Quevenne reading at 15.5° C. after 
holding the sample at 37-40° C. 45 minutes, and/ the per cent of fat. 

Determination of Fat in Sweetened Condensed Milk. — It has long been 
known that fat can not be accurately determined in sweetened condensed 
milk either by extraction after evaporation, as in the asbestos or paper coil 
methods, or by the ordinary centrifugal methods. In the former case the 
sugar encloses particles of fat and prevents their contact with the ether 
while in the latter case it chars with the acid and gives a black fat column. 
In exact work the Rose-Gottlieb Method (p. 193) should be used but for 
many purposes the two following modifications of the Babcock method are 
sufficiently accurate. 

Leach Method.^ — In a Babcock milk bottle with a mark on the bulb 
showing a volume of 17.6 cc, place 25 cc. of the diluted sample, add 4 cc. 
of copper sulphate solution of the strength used for Fehling solution, and 
allow to stand some minutes without shaking. Add water nearly to the 
neck, shake thoroughly, and whirl without heating in a centrifuge until the 
precipitated proteins, carrying with them the fat, have entirely settled. 
Remove the clear liquid, add water nearly to the neck, break up the lumps 



*Ind. Agr. Exp. Sta. Rept., 1913, p. 43. 

t Jour. Ind. Eng. Chem., 9, 191 7, p. 499. 

t Mass. State Bd. Health Rept., 1896, p. 630; Jour. Amer. Chem. See, 22, 1900, p. 580. 
SHght changes in the manipulation which Winton has found desirable are given in the above 
description. 



180 FOOD INSPECTION AND ANALYSIS. 

with a wire, shake, and again whirl. After removing the clear liquid 
repeat once again the addition of water, shaking, whirling, and decanta- 
tion. Finally add water up to 17.6 cc, mix thoroughly, and proceed as 
in the usual Babcock method. To obtain the percentage of fat, multiply 
the reading by 18 and divide by the grams of condensed milk in the aliquot 
taken. 

Farringion Method.^ — Weigh 40 to 60 grams of the sample into a 2cc-cc. 
flask, dissolve in 100 cc. of water, make up to the mark, and shake. 
Pipette 17.6 cc. into a milk test-bottle, add 3 cc. of sulphuric acid of the 
strength used for the test, and shake thoroughly. Whirl for 6 minutes at 
1000 revolutions per minute in a steam-driven turbine centrifuge in which 
the chamber reaches a temperature of about 93° C, pour off cautiously the 
clear solution, add 10 cc. of water, shake, then add 3 cc. of acid, whirl, and 
decant a second time. Shake the curd with 10 cc. of water and proceed as 
in the ordinary Babcock test, calculating to the weight of sample taken. 

Determination of Fat in Evaporated Milk. — The finely curdled particles 
of casein formed during sterilization enclose fat which is removed with 
difficulty by ether extraction. Hunziker and Spitzer f found that, after 
removing the greater part of the casein from the Adams coils by dilute 
acetic acid, extraction for 8 hours gave the full amount of fat. The asbes- 
tos and sand methods are preferable to the Adams method and thorough 
distribution by dilution facilitates the extraction. Extensive investigations 
by Patrick and others indicate that the Rose- Gottlieb method gives the best 
results. 

The curd flocks are dissolved with difficulty in the Babcock acid, 
hence clear readings and the full amount of fat are not always obtained 
by the usual process. The Hunziker and Spitzer Method, by the use of 
a quarter quantity of the sample and hot i : i acid in filling the test- 
bottles, largely obviates these defects. Utt % finds additional heating 
essential and Bigelow and Fitzgerald, § in their modification, use 9 grams of 
the sample, read to the bottom of the meniscus, and add 15% to the result. 

As such factors as temperature, thoroughness of mixing, period of 
action, and method of reading influence the results, the analyst should test 
his procedure against a standard method or with standard samples derived 
from milk of known composition evaporated to a definite concentration. 

* Amer. Chem. Jour., 24, 1900, p. 267. 

find. Agric. Exp. Sta. Bui. 134, 1909, p. 591. 

t Jour. Ind. Eng. Chem., 5, 1913, p. 168. 

§ Reb. Lab. Nat. Canners' Assn. Bui. 5, 1915, p. 8. 



MILK AND ITS PRODUCTS. 



181 



Determination of Protein. — Proceed with an aliquot of the diluted 

sample as described under milk (p. 132), calculating the protein from 
the total nitrogen or determining it directly by the Ritthausen method. 

Determination of Lactose. — Volumetric Method. — Pipette 25 cc. of the 
40% solution into a 500 cc. flask and proceed as directed under milk 

^P- 137)- 

In calculating the percentage of lactose use the following formula : 



L = 



100X0.067 
5Xo.o2 



in which L is the per cent of lactose and S the number of cubic centimeters 
of 40% solution required to reduce 10 cc. of Fehling solution. Calculation 
may be avoided by the use of the following table: 



PER CENT MILK SUGAR CORRESPONDING TO NUMBER OF CUBIC 
CENTIMETERS USED. 

Strength of solution 2 grams in 100 cc. 



Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


Cu. Cm. 


Per Cent. 


18.0 


18.61 


25.0 


13-40 


32.0 


10.47 


39-0 


8.59 


18.S 


18 


10 


2SS 


13 14 


32 


5 


10 


31 


39-5 


8 


49 


19.0 


17 


63 


26.0 


12.89 


33 





10 


15 


40.0 


8 


37 


195 


17 


18 


26. 5 


12.64 


33 


5 


10 


00 


40-5 


8 


27 


20.0 


16 


75 


27.0 


12.41 


34 





9 


85 


41.0 


8 


17 


20. s 


16 


34 


27-5 


12.18 


34 


5 


9 


71 


41-5 


8 


07 


21.0 


IS 


95 


28.0 


11.97 


35 





9 


57 


42.0 


7 


98 


21-5 


15 


58 


28. s 


11-75 


35 


5 


9 


43 


42-5 


7 


88 


22.0 


IS 


22 


29.0 


ii-SS 


36 





9 


30 


43-0 


7 


78 


22-5 


14 


89 


295 


11-35 


36 


5 


9 


17 


43-5 


7 


70 


23.0 


14 


S6 


30.0 


II. 16 


37 





9 


05 


44.0 


7 


61 


23s 


14 


25 


30-5 


10.89 


37 


5 


8 


93 


44-5 


7 


53 


24.0 


13 


95 


31.0 


10.80 


38 





8 


81 






24-5 


13 


67 


31-5 


10.63 


38 


5 


8 


70 







Gravimetric Methods. — Lactose may be determined in the 40% solu- 
tion of the condensed milk by the O'Sullivan-Defren method (p. 137), 
the Soxhlet method (p. 137), or the Munson and Walker method (p. 138), 
the solution being treated exactly as if it were milk. 

It has long been known that the percentages of lactose by copper 
reduction in sweetened condensed milk are somewhat high owing to the 
presence of sucrose. This appears to be due to the sucrose itself rather 
than to reducing sugars present in it as impurities. Winton found, in an 



182 FOOD INSPECTION AND ANALYSIS. 

attempt to determine the corrections for different proportions of sucrose, 
that while agreeing results could be obtained on solutions of pure lactose, 
when a definite amount of sucrose was added the figures were not merely 
higher but were discordant even when the heating and other conditions 
were apparently the same. The experience of Knight and Formanek 
would seem to indicate that greater accuracy can be secured by directly 
determining the sucrose and obtaining the lactose by difference. 

Cane Sugar.— This is ordinarily obtained by difference, deducting the 
milk solids (the sum of the milk sugar, proteins, fat, and ash) from the 
total solids first obtained. 

When only the sucrose is desired this may be determined by polariza- 
tion. The Knight and Formanek method depends on double dilution 
(see Wiley method, p. 136) to correct for the bulk of the precipitate and 
on a modified Clerget formula to eliminate the rotatory influence of the 
lactose. Rakshit * destroys the lactose entirely by means of a measured 
quantity of Fehling solution calculated from a volumetric determination. 

Knight and Formanek Method. -\ — Make the entire contents of the 
usual 12 to 15-ounce can up to 500 cc. Place 50 and loo-cc. aliquots in 
200-cc. flasks and clarify with 1.7 cc. of 5% phosphotungstic acid solution 
and 2.1 cc. of 25% normal lead acetate solution for each 10 grams of the 
sample in the aliquot, shaking well after adding each reagent. Make up 
to the mark, shake again and filter. To the filtrates, measuring about 100 
cc, add potassium oxalate crystals in o.i-gram portions with constant 
shaking until a curdy precipitate forms which quickly settles leaving a 
clear liquor. Usually 0.5 gram is sufiicient; a large excess should be 
avoided. Filter again using hardened filters with 3 to 5 grams of fuller's 
earth in the apex and test the first 10 cc. with potassium oxalate. Polarize 
at exactly 20° C. preferably in a Bates instrument set for maximum senti- 
tiveness and using a bichromate cell. Multiply the reading of the dilute 
solution by 4 and subtract from the product the reading of the stronger 
solution. The difference is the direct polarization corrected for the volume 
of the precipitate. 

Pipette 50-cc. portions of the filtrates into loo-cc. flasks and invert 
with 5 cc. of concentrated hydrochloric acid by standing over night at 
20 to 25° C. Add a few drops of phenolphthalein solution and strong 
sodium hydroxide solution until a pink color appears, then a few drops of 
N/io hydrochloric acid until the color disappears. Make up to the 

* Jour. Ind. Eng. Chem., 6, 1914, p. 307. 
t IL>><J-, 8, 1916, p. 28. 



MILK AND ITS PRODUCTS. 183 

mark, cool at room temperature and polarize as before using 400 mm. tubes 
for instruments other than Bates. Subtract the reading of the strong 
solution from four times that of the weak and multiply the difference 
by 2 (except when 400-mm. tubes were used) thus obtaining the invert 
polarization {P') corresponding to the direct polarization (P). The per 
cent of sucrose (5) is obtained by the following formula: 

y_ 26 ooo{P- P') 

in which W is the weight of condensed milk in the can and T is the degrees 
Centigrade of the invert readings. 

Detection of Foreign Fats and Oils.— The invention of the homogenizer 
has led to the preparation of emulsions of oleo, cotton seed and other oils, 
as well as of butter fat, with skim milk and milk in imitation of whole milk 
and cream and the use of such homogenized products in condensed milk 
and ice cream. This substitution is detected by the separation and exami- 
nation of the fat as follows: 

Paul's Method."^'— Dilute 100 grams of the material with 300 cc. of 
water, heat to boiling and add slowly, while boiling, 25 cc. of Fehling's 
copper sulphate solution. 

Filter through a filter paper on a Buchner funnel, wash three times 
with hot water and allow to suck dry. Remove filter and precipitate from 
the funnel, break into small pieces, dry over night at room temperature 
and grind with about 25 grams of anhydrous copper sulphate. 

Place a layer of anhydrous copper sulphate in the bottom of the inner 
tube of a Johnson extractor (p. 54), then add the powdered mixture and 
place a loose plug of cotton on the top. Connect the extractor with a 
flask, pour 50 cc. of ether through the mixture and proceed as usual with 
the extraction. 

Dry the fat as quickly as possible and weigh. Determine the refractive 
index, volatile fatty acids and such other constants as seem desirable 
(Chapter XIII). 

Calculation of Fat in Original Milk. The " fat in original milk," as 

given in the tables on pages 176 and 177, was calculated by assuming a 
percentage of solids not fat of 9.3 in the original milk, this being the standard 
fixed by the Massachusetts law. Calculate first the fat and the milk 
solids to the basis of the cane-sugar-free sample. This is done by divid- 

* U. S. Dept. of Agric, Bur. of Chem., Circ. 90, p. 10. 



184 FOOD INSPECTION AND ANALYSIS. 

ing the per cent of each as found in the sample by loo less the percentage 
of cane sugar, and multiplying the result by lOo. Ascertain the dif- 
ference between the milk solids and the fat thus obtained in the cane- 
sugar- free sample, and divide this percentage of milk solids not fat by 
9.3. The result is the "number of times condensed " (if cane sugar were 
not present as a diluent). 

The per cent of fat in the cane-sugar-free sample, divided by the 
number of times condensed, as above obtained, gives the percentage of 
fat in the original milk. 

The above calculation from the solids not fat of the factor desig- 
nated as "the number of times condensed," necessitates determinations of 
fat, ash, proteins, and milk sugar, in fact, a complete analysis o^ the sample. 

A simpler method of calculating the " number of tim'' condensed," 
involving determinations of fat and ash only in the san pie, consists in 
dividing the per cent of ash found in the condensed milk by 0.7, this 
figure being the assumed ash of normal, standard milk. Then, by divid- 
ing the fat in the sample by the " number of times condensed " as last 
calculated, the result is the fat in the original milk. If this is found 
to be well below 3%, there is reason to suspect that skimmed milk was 
used in its preparation. 

The " fat in the original milk " as thus calculated is, of course, an 
arbitrary factor and is useful only in deciding whether or not skimmed 
milk has been used in preparing the sample. By assuming the above 
very reasonable figures for the solids not fat, or for the ash of natural 
milk (according to which method is used for calculation), it is readily 
seen that the highest result is obtained for the " fat in the original milk " 
and hence the benefit of the doubt as to the use of skimmed milk is 
^ven to the manufacturer. 

MILK POWDER. 

There are numerous brands of desiccated milk or milk powder on the 
market, sold in bulk and by the can, and largely used by bakers and manu- 
facturers of milk chocolate. Many of these, purporting to contain all the 
ingredients of milk excepting water, have been found to be pulverized 
dried skimmed milk. 

In the table on page 185 are given the maximum and minimum figures 
obtained by Fleming * in 2 samples of cream powder and i of whey powder, 

* Jour. Ind. Eng. Chem., 4, 191 2, p. 543. 



MILK AND ITS PRODUCTS. 



185 



and by Stewart* in 7 samples of whole milk powder, i of half skim milk 
powder, and 8 of skim milk powder. 



Cream Powder.* 



Whole Milk 
Powder, t 



Half • 
Skim Milk 
Powder.t 



Skim Milk 
Powder.t 



Whey 
Powder.* 



Water 

Fat 

Lactose 

Total protein . . . 
Soluble albumin. 
Ash 



0.81-0.76 

•67-64-53.08 
26.04-15.92 
16.89-12. 21 



3.78- 2.67 



S-52- 146 

30.00-23. 55 

41.23-34.48 

27.69-23.92 

6 . 06- I . 60 

6-33- 5-33 



8.00- 4.76 
1 . 86-' o . 34 
54.07-48.41 
35.72-31.96 
8.03- 1.25 
8.43- 7.26 



1.40 

0.60 

77.20 

12.50 

10. 20 

9. 10 



Analyses by Fleming. 



t Analyses by Stewart. 



Analysis of Milk Powder. 

The methods designed for milk apply in general to milk powder, observ- 
ing certain precautions: 

Determination of Fat. — The Rose-Gottlieb and Werner-Schmidt methods 
are applicable. Neither extraction of the dry material with absolute 
ether nor the Babcock method yields the full amount of fat. McLellan t 
obtained satisfactory results extracting with concentrated (not absolute) 
ether (sp.gr. 0.72), extending the extraction through 2 days, and soaking 
over night before each extraction. Fleming also uses concentrated ether 
but finds 16 hours' extraction without soaking sufficient. 

Redmond Modification of the Babceck Method.^ — Weigh 2.5 grams of 
the powder into a clean dry Babcock milk bottle, using a smali funnel to aid 
in transferring. Add 31 cc. of dilute sulphuric acid (395 cc. of cone. 
H2SO4 diluted to i liter) and heat in a dish of gently boiling water, with 
frequent shaking, until all the powder is dissolved and the mixture is 
dark brown which usually requires 7 to 10 minutes. Remove from the 
water, add 12 cc. of sulphuric acid (sp.gr. i. 82-1. 83), mix thoroughly, and 
proceed as in the usual Babcock method. Place in water at 55 to 80° C, 
read the fat to 0.05 on the scale and multiply the reading by 7.2. 

Determination of Lactose. — Follow the usual methods, grinding any 
lactose crystals that may be present to a powder, and dissolving in warm 
water. 



* Eighth Int. Cong. App. Chem., 18, 1912, p. 329. 

t Analyst, 31, 1908, p. 353. 

t Jour. Ind. Eng. Chem., 4, 191 2, p. 544. 



186 



FOOD INSPECTION AND ANALYSIS. 



CREAM. 

Composition. — Cream varies in composition according to the method 
by which it is obtained, i.e., whether (i) by allowing it to separate from the 
milk set in shallow pans, whence it is removed by hand-skimming, (2) 
by setting in deep vessels surrounded by cold water (as for example in the 
" Cooley " creamer) the skimmed milk being commonly drawn off from 
below, or (3) by the centrifugal separator. Most of the heavy cream 
found in the market at the present time is the product of the third or 
separator process. Analyses of different kinds of cream follow: 

COMPOSITION OF CREAM. 



Character of Cream. 


2 


r. 



3 
< 






C 


i 




4 
< 


3 

'rt'o 



c 

eg 


By natural separation 

By centrifugal separator, 
"Heavy" cream 


46 

18 

18 


Konig 
Leach 

Leach 


Mean 

Maximum 

Minimum 

Mean 

Maximum 

Minimum 

Mean 


68.82 

54.80 
46.76 
51.68 
83.29 
70.50 
77.89 


3-76 


22.664.23 

4.6.40 


0-53 


31.18 

53-24 
45.20 

48.32 
29.50 
16.71 
22.11 


8.42 

8.5c 

4.20 

6.30 
9-30 

7.22 

8.25 


"Light" cream 


38.10 
42.02 
21.60 
8.60 
13.86 


'.'.'.'. 





XJ. S. standards.* — Standard Cream is cream containing not less than 
18% of milk fat. Standard Evaporated Cream is cream from which a 
considerable portion of water has been evaporated. 

Adulteration of Cream. — In some localities fat standards are fixed 
for cream both " heavy " and " light," those falling below such standards 
being deemed adulterated. 

Foreign Fats. — Oleo oil, possibly other fats, " homogenized " or 
emulsified with milk or skim milk, is now being substituted for true cream. 
A product known as " Syntho " belongs in this class but is sold by its 
manufacturers under its true name. 
. Preservatives. — The same preservatives are employed in cream as in 
milk. 

Gelatin. — The author has detected this substance in cream sold in 
Massachusetts. It serves as a thickener and is sometimes sold in powder 
form mixed with boric acid. 



U. S. Dept. of Agric, Off. of Sec, Circ. 19. 



MILK AND ITS PRODUCTS. 



187 



Sucrate of Lime in Milk and Cream.— Pasteurizing reduces the con- 
sistency of cream so that its apparent richness and its value for certain 
culinary preparations is impaired. Babcock and Russell * have shown 
that sucrate of lime {" viscogen ") may be used to thicken such cream, 
but insist that the treated product be sold under a distinctive name, such 
as " visco-cream " or "pasteurized visco-cream." 

To prepare " viscogen " dissolve 2| parts by weight of cane-sugar in 
5 parts of water, add, after straining, i part of quicklime slaked in 3 parts 




Fig. 53.— a Babcock Cream-test Scale. 



of water; shake, allow to settle, siphon off the supernatant liquid, and 
bottle. For thickening cream use two-thirds of the amount required to 
neutralize its acidity. It will also thicken milk and condensed milk. 



ANALYSIS OF CREAM. 

^ Total solids, ash, sugar, proteins, and fat (gravimetric) are deter- 
mined by the methods used in milk analysis (pp. 1 19-138). 

Determination of Fat.— Babcock Process. —Owing to the viscosity of 
cream and its variation in density strictly accurate results can be secured 
only by weighmg the sample. Fig. 53 shows a cream scale provided with 
a sliding poise for balancing the bottle and a second for weighing the 
cream. If a large number of tests are to be made, a balance for weighing 

* Wisconsin Exp. Station, Bui. 54. 



188 



FOOD INSPECTION AND ANALYSIS. 



T 



-_30 

=^28! 



B 



several samples on each pan or the Wisconsin hydrostatic cream balance 
will be found convenient.* The latter, devised by Babcock and Farring- 
ton,t is constructed on the principle of the lactometer. It is pro- 
vided with a pan on the top of the stem for holding the test bottle and 
weights. 

Two forms of test bottles are shown in Fig. 54. Others with grad- 
uations up to 50% are also obtainable. 

J The process is as follows: Weigh 9 or 

18 grams of the well-mixed sample into the 
tared test bottle, using a pipette with a wide 
delivery tube. If 9 grams are used dilute 
with 9 cc. of water. Add 17.5 cc. of sulph- 
uric acid of proper strength and proceed as in 
the case of milk (p. 123). 

The error due to the curved meniscus of 
the fat column in the test bottle may be 
overcome by adding a few drops of fat- 
saturated alcohol (Babcock and Farrington |) 
or of glymol (Hunziker §). 

/' . I — Ml '^^ prepare fat-saturated alcohol place a 

\\ J V\v teaspoonful of butter in a bottle with 200 cc. 
of denatured or wood alcohol, warm slightly 
and shake until saturated. Coloring matter 
may be added to further facilitate the read- 
ing. Glymol may be colored with alkanet 
root. 

Detection of Foreign Fats. — Determine 
the refractive index and the volatile fatty 
acids of the fat obtained by the Babcock 
method. 

Detection of Preservatives. — See pp. 162-169. 

In testing for formaldehyde, using ferric chloride and hydrochloric 
acid, the sample should be diluted with an equal volume of water, heated 
with the reagents in a casserole but finally poured into a test tube to 
observe the color. 



Fig. 54. — ^Varieties of Babcock 

Test Bottle for Cream. 

A, Bartlett Bottle; B, Winton 

Bottle. 



* Farrington and WoU, Testing Milk and its Products, 20th Ed., pp. 81-83. 

t Wisconsin Exp. Station, Bui. 195. 

X Loc. cil. 

§ Ind. Agric. Exp. Sta. Bui. 145, p. 193. 



MILK AND ITS PRODUCTS. 189 

Detection of Gelatin. — Stokes Method.'^ — The reagents are as follows: 
(i) Acid nitrate of mercury, prepared by dissolving metallic mercury in 
twice its weight of concentrated nitric acid (sp.gr. 1.42) and diluting 
with twenty-five times its bulk of water, and (2) a saturated aqueous 
solution of picric acid. 

To about 10 cc. of the cream add the same amount of the acid nitrate 
of mercury solution and 20 cc. of cold water. Shake the mixture vigor- 
ously and allow to rest for five minutes, after which filter. If much 
gelatin is present, the filtrate will not be clear, but opalescent. To the 
whole or a part of the filtrate add a few drops of the picric acid solution. 
If gelatin be present in any considerable amount, a yellow precipitate 
is formed. Avoid an excess of acid nitrate of mercury, as this would 
cause a precipitate with picric acid. 

If gelatin is present in small amount only, a cloudiness is produced, 
best seen against a dark background. The reaction is delicate to i part 
of gelatin in 10,000 parts of milk or cream. 

Sour cream, not containing gelatin, gives a protein precipitate by this 
method. Seidenberg | differentiates this from gelatin picrate as follows: 

Shake the solution and precipitate in a large test-tube very thoroughly, 
allow to stand, decant off the clear liquid, and collect the precipitate on a 
filter. Wash with water containing 2 to 3 drops of ammonia water per 
100 cc. until the washings are slightly alkaline to litmus, then with water 
alone until they are neutral. Transfer the precipitate, or the precipitate 
and filter, to a small beaker, add 10 to 20 cc. of water, heat to boiling, 
and filter hot into a test-tube. The filtrate will contain the gelatin picrate 
but not the protein. Cool and test for gelatin by adding an equal volume 
of the picric acid solution. 

Detection of Sucrate of Lime. — This is indicated by the presence of 
sucrose, in connection with an abnormally high alkalinity of ash and 
excessive calcium oxide. The tests are as follows : 

Lythgoe's Modification of Baier and Neuman's Test for Detecting 
Sucrose.t — To 25 cc. of milk or cream, add 10 cc. of a 5% solution of 
uranium acetate, shake well, allow to stand for 5 minutes, and filter. 
To 10 cc. of the clear filtrate (in the case of cream use the total filtrate, 
which will be less than 10 cc.) add a mixture of 2 cc. saturated ammo- 
nium molybdate and 8 cc. dilute hydrochloric acid (i part 25% acid 

* Analyst, 22, 1897, p. 220. 

t Jour. Ind. Eng. Chem., 5, 1913, p. 927. 

X Zeits. Unters, Nahr. Genussm., 16, 1908, p. 51. 



190 FOOD INSPECTION AND ANALYSIS. 

and 7 parts water), and heat in a water-bath at 80° C. for 5 minutes. If 
the sample contains sugar, the solution will be of a Prussian blue color, 
which should be compared in a colorimeter with standard Prussian blue 
solution, prepared by adding a few drops of potassium ferrocyanide to 
a solution of i cc. of 1% ferric chloride in 20 cc. of water. 

Occasional samples of pure milk will give a pale blue color, but this 
can be entirely removed by filtration, the filtrate being green, while the 
color due to sugar will pass through the filter, giving the usual blue solution. 
This color, due to a reduction of molybdic acid, is also produced by levulose 
and dextrose. Solutions of i gram of lactose, levulose, dextrose, and 
sucrose in 35 cc. of water heated with molybdenum reagent for 5 minutes 
reacted as follows: lactose no color, levulose a heavy blue, sucrose a weaker 
blue, and dextrose the weakest blue, the intensity of the last three being 
as 10 : 3 : I. 

Stannous chloride, ferrous sulphate, and hydrogen sulphide give this 
blue color in the cold, but it disappears on heating except in case the 
stannous or ferrous salt is present to the extent of at least 1% (calculated 
as the metal) which amount would coagulate the cream and impart a very 
disagreeable taste. 

As a confirmatory test for sugar, the resorcine test may be applied 
to the serum prepared with uranium as described above. This test is 
given by sucrose and levulose, but not by dextrose or lactose. 

Determination of Alkalinity of Ash and Calcium Oxide. — Weigh 
25 grams of cream into a platinum dish, place in an oven at about 
125 to 150° C. over night, and burn to an ash in a mufHe at a low-red 
heat. Dissolve the ash in 20 cc. N/io sulphuric acid, boil to exDel 
the carbon dioxide, and titrate back with N/io sodium hydroxide, using 
phenolphthalein as the indicator. Express results as cc. N/io acid 
required to neutralize the ash of 100 grams of cream. 

Make the final solution of the above determination acid with acetic 
acid, heat to boiling, add i gram of sodium acetate, and to the clear 
solution add an excess of ammonium oxalate, boil for a few minutes, 
filter, and wash with water. Dissolve the calcium oxalate in hot dilute 
sulphuric acid, and titrate hot with N/io potassium permanganate. 
The number of cubic centimeters of N/io permanganate, multiplied by 
0.0112 (4X0.0028), gives the percentage of CaO in the sample. 

Lythgoe and Marsh * have calculated the maximum percentages of 

* Jour. Ind. Eng. Chem., 7, 1910, p. 327. 



MILK AND ITS PRODUCTS. 191 

calcium oxide C corresponding to the percentages of fat F within the limits 
of 15 and 54%. The following formula is based on their figures: 

C=o.i8i —0,00246(2^ — 15). 

ICE CREAM. 

For many years a wide variety of iced foods have been made and 
sold under the general name of ice cream, many of which are largely 
composed of ingredients other than milk or cream. In the study and 
classification of foods of such a miscellaneous nature as ice cream, in its 
popularly accepted meaning, it is not always easy to satisfactorily define 
and fix standards, either as regards the constituents or the minimum limit 
for butter fat. 

This perplexity, which exists in standardizing all mixtures, is increased 
in the present instance by a name which suggests merely frozen cream 
when milk, condensed milk, skim milk, emulsions of butter fat, oleo oil, 
or cotton-seed oil may be present. Had frozen creamy mixtures come to 
be known under a generic non-suggestive name they might now pass un- 
challenged, like cake and pudding, regardless of their food constituents, 
provided nothing unwholesome was used in their preparation. It has, 
indeed, been argued that the name ice cream is strictly analogous to names 
such as cake and pudding, the word cream referring merely to the creamy 
nature of the product. As precedents for such a usage the names creamed 
potatoes, chocolate creams, cream of wheat, and crime de menthe are 
cited. While this is an extreme view it serves to illustrate the difficulties of 
establishing a system of nomenclature that will prevent deception and at 
the same time not discourage the use of wholesome substitutes, or be more 
exactingfor one class of products than another. 

U. S. Standards.* — Ice cream is a frozen product made from cream 
and sugar with or without a natural flavoring, and contains not less than 
14% of milk fat. 

Fruit ice cream is a frozen product made from cream, sugar, and 
sound, clean, mature fruits, and contains not less than 12% of milk fat. 

Nut ice cream is a frozen product made from cream, sugar, and sound, 
non-rancid nuts, and contains not less than 12% of milk fat. 

These standards have given rise to much controversy and have never 
become universally recognized. Certain states have established standards 
of their own. 

* U. S. Dept. of Agric, Ofl&ce of Secretary, Circ. 19. 



192 FOOD INSPECTION AND ANALYSIS. 

Classification.— Washburn * recognizes two divisions: (i) Plain ice 
cream, which is an uncooked mixture of cream, sugar, and flavoring mate- 
rial, usually with gelatin or some other binder but rarely or never with 
eggs and (2) French or Neapolitan ice cream, which contains eggs and is 
virtually a frozen custard. 

Water ices although containing no milk or cream should be mentioned 
in this connection as they are made by practically the same freezing process 
and are often packed in bricks in layers alternating with ice cream of dif- 
ferent flavors. 

Mortensen f extends the classification so as to cover a wide variety of 
frozen desserts. 

Influence of Ingredients and Process. — Washburn % after an extensive 
investigation has reached the following conclusions: 

"The flavor is influenced by the fat content of the cream; by its 
freedom from contamination of all sorts; by a low cream acidity; by 
the addition of minute quantities of common salt; and by the ripening or 
aging of the ice cream. A good body is the result of the presence of plenty 
of fat, but not too much; of the aging and thorough cooling of the cream; 
and, sometimes, of the use of fillers. A fine texture is promoted by the rich- 
ness of the cream; by the proper conduct of the freezing process; by the 
aging of the cream; and, if the goods are not to be used promptly, by the 
use of a gelatinoid binder. Swell (or overrun) is caused by the incorpora- 
tion of air into the cream and is affected by the viscosity of the cream; 
by the rate of freezing; and particularly by the length of time elapsing 
while the cream is dropping from 34 to 29° F.; and by the speed of the 
agitating mechanism. The richness or the leanness of the cream within 
working limits has little effect thereon; neither does the use of gelatin, 
gum tragacanth or other binders. . . . 

" A clean cream is of course essential. Neither a very rich nor a too 
thin cream should be used, about 22% fat seeming ideal. A day's keeping 
improves cream, and if it is kept cold so much the better, since the fat glo- 
bules harden and a better body is obtained. Acidity is to be decried, 
although ufiless excessive it is not fatal to success. A pasteurized cream, 
if allowed to age, may be used to advantage. The homogenation of cream 
greatly increases its viscosity and tends to better the body, texture and 
general creaminess of the final product. There is no essential difference 

* Vt. Agric. Exp. Sta., Bui. 155, 1910, p. 6. 
t Iowa Agric. Exp. Sta., Bui. 123, p. 353. 
X Loc. cil. 



MILK AND ITS PRODUCTS. 193 

between centrifugal and gravity creams as used in ice cream making; 
condensed milk may be used to advantage to better the body and smooth- 
ness of the goods. 

" A filler is used to give body; a binder to prevent coarse crystalliza- 
tion when held for one day or longer. Starch, flour, eggs, and rennet are 
used as fillers with greater or less satisfaction, generally less. Gelatin, 
gum tragacanth, and ice cream powders are used as binders often with good 
satisfaction ; but their use, though legal in \^ermont, is forbidden in several 
states. There appears to be arguments on both sides of the question as to 
the advisability of the use of binders in commercial cream. The adverse 
arguments are that inferiority and age are thus concealed, the swell unduly 
augmented, the use of low grade materials encouraged, insanitary holding 
conditions favored, and adequate food control rendered difficult. Those 
advanced in favor of their use are that they prevent granulation and conse- 
quent deterioration, discourage the return and re-usage of unsold goods, 
and assist trade re,gulations." 

Homogenized Products. — Unsalted butter emulsified with milk or 
skim milk is now extensively substituted for true cream in the manufacture 
of so-called ice cream. Oleo oil and cotton seed oil are also used in such 
emulsions; neither of these oils is considered permissible in the product 
sold as ice cream. 

Ice Cream Cones. — These are cornucopias made of a kind of dr}^ crust 
used to serve ice cream without a spoon, the cones as well as the ice cream 
being eaten from the hand. In addition to flour, sugar, and eggs or gjlatin, 
which are proper constituents, they frequently contain saccharin, artificial 
color and borax, the latter being used to prevent sticking to the mold 
during baking. 

ANALYSIS OF ICE CREAM. 

Determination of Fat. — Rose-Gotllieh Metlwd.'^ — Prepare a 40% 

solution, as for condensed milk (p. 178). Of this solution rrcasure 10 cc. 
into a Rohrig tube f (Fig- 55)) or a glass cylinder 2 cm. in diameter and 
40 cm. high, to which a narrow siphon can be fitted; dilute with 0.5 cc. of 
water, add 1.25 cc. of concentrated ammonium hydroxide (2 cc. if the 
sample is sour) and mix thoroughly. Add 10 cc. of 95^^ alcohol and 
shake well. Then add 25 cc. of washed ethyl ether, shake vigorously 

* Rose, Zeits. angew. Chem., 1889, p. 100; Gottlieb, Landw. Versuchs-Stat., 40, 1892, 
p. i; Patrick, U. S. Dept. Agric, Bur. of Chem., Circ. 66. 
t Zeits. Unters. Nahr. Genussm., 9, 1905, p. 531. 



194 



FOOD INSPECTION AND ANALYSIS. 



for half a minute, add 25 cc, of petroleum ether (p. 55), preferably redis- 
tilled below 60° C, and shake again for half a minute. Let stand twenty 
minutes or until the upper liquid is clear and its lower level constant. 

Draw off as much as possible of the ethereal liquid — usually 0.5 to 

0.8 cc. is left — through a diminutive filter into a weighed flask. Extract 

the liquid remaining in the tube in the same manner as before except 

A that only 15 cc. each of the ethers are used, draw off 

through the same paper into the flask and wash with a 

few cc. of the mixed ethers (1:1). Evaporate the drawn 

off and filtered liquid slowly and dry in a boiling-water 

oven, one hour at a time, to constant weight. The ether 

used must be tested for residue upon evaporation and a 

correction introduced if necessary. 

The dried and weighed fats should be dissolved in a 
little petroleum ether; if a residue be found (due to a trace 
of the aqueous liquid which may have passed the filter) it 
must be washed in the flask, dried, and its weight de- 
ducted from that of the crude fat. 

This method is also applicable to condensed milk, 
cream, milk, skim milk, buttermilk, and whey. With 
substances of low fat content the second extraction may be 
omitted, the weight of the fat being increased to corre- 
spond to the entire volume of ethereal liquid measured in 
the tube. 

White MetJiod* — Weigh into a Babcock milk bottle 
6 grams of the melted and well-mixed sample, dilute to 
18 cc, and add 8 cc. of sulphuric acid in two portions, 
allowing 2 minutes to elapse before adding the second 
portion and mixing carefully after each addition. The mixture should be 
light brown and not black as in the case of milk. If a black color is 
obtained — due to the violent action on the sugar because of a low percentage 
of casein — repeat the test using a smaller amount of acid. Whirl in a steam 
centrifuge for 3 minutes at a high speed then fill to the neck with distilled 
water at 65° C. If black particles are mixed with the fat shake vigorously 
for a few seconds, whirl again for 3 minutes, add water so as to bring the 
fat within the scale, whirl the third time for 2 minutes, and read at 63° C. 
Multiply the reading by 3 to obtain the per cent of fat. 




Fig. 55.— Rohrig 
Tube for Rose- 
Gottlieb Meth- 
od. 



* Penn. Agric. Exp. Sta. Rep., 1910, p. 243. 



MILK AND ITS PRODUCTS. 195 

Halverson * also uses only sulphuric acid, added in portions, as a 
reagent but the details of the process are different from those of the fore- 
going. The test is made in a special bottle for drawing oflf the acid liquid 
after the second whirling. 

Lichtenberg Method. '\ — Weigh into a Babcock milk bottle 9 grams of 
the melted and well-mixed sample. Add 20 cc. of glacial acetic acid 
(sp.gr. 1.049), ^i^ well, then add 10 cc. of sulphuric acid (sp.gr. 1.83) 
and mix again. Proceed as in the regular Babcock test reading the fat 
column from one extreme to the other at 55° C. The reading multiplied 
by 2 gives the per cent of fat. 

Utt % follows essentially the same method with minor changes in the 
proportion of the reagents and details of manipulation. 

Detection of Foreign Fats and Oils. — Separate and examine the fat as 
described on page 183. 

Detection of Thickeners. — Patrick's Method A — Add 25 cc. of water 
to 50 cc. of the sample, and boil till any thickener present is dissolved. 
Add 2 cc. of a 10% solution of acetic acid, heat to boiling, add 3 heap- 
ing teaspoonfuls of kieselguhr, and after shaking pass at once through 
a plaited filter. To 3 cc. of the clear filtrate add 12 cc. of 95% alcohol 
and mix thoroughly, thus precipitating the milk proteins not already 
removed, and also the gums and some of the gelatin, if much is present. 
Add 3 cc. of a mixture of 95 cc. of 95% alcohol and 5 cc. of concen- 
trated hydrochloric acid. This acidified alcohol dissolves completely the 
milk proteins, and, if a clear solution then remains, no gums or vegetable 
jellies have been used as thickeners. Turbidity does not, however, 
necessarily indicate presence of a thickener, as it may be caused by a 
large amount of eggs, or by the souring of the ice cream. Dilute the 
mixture, if turbid, by adding 3 cc. of water. Any precipitate due to 
gelatin or eggs will be dissolved at this dilution, but not that due to 
vegetable gums. If gum tragacanth be present, the precipitate will be 
stringy and cohesive, especially after shaking, while agar-agar or other 
vegetable thickeners will cause a fine flocculent precipitate. 

Souring of the ice cream sometimes produces a turbidity or precip- 
itate under the above conditions, which is not always dissolved after 
diluting with water. Formation of such a precipitate (due to sourness) 
may, however, apparently be prevented by the previous addition of 
formaldehyde to the sample. 

* Jour. Ind. Eng. Chem., 5, 1913, p. 403. |Ibid., 7, 1915, p. 773. 

t Ibid., 5, 1913, p. 786. § U. S. Dept. of Agric, Bur. ofChem., Bui. 1 16, p. 26. 



196 FOOD INSPECTION AND ANALYSIS. 

Howard's Test for Gums. — Precipitate lo cc. of the melted sample 
with acetone, and wash with 2 or 3 portions of dilute alcohol, using 
the centrifuge. Boil the washed residue with 6 to 8 cc. of water and 
I cc. of 10% sodium hydroxide solution for half a minute. Cool, let 
stand a few minutes, filter, and heat the filtrate to boiling. Add one 
and one-half volumes of warm alcohol and shake. If agar-agar or gum 
tragacanth be present, a fiocculent precipitate will immediately sepa- 
rate. Disregard a mere turbidity. To prove the absence of any con- 
siderable quantity of milk proteins in the precipitate, dissolve in cold 
water and saturate the solution with ammonium sulphate. 

Gelatin. — Use the method of Stokes (p. 189) on 10 to 15 cc. of the 
sample, disregarding a faint cloudiness at the end. 

Starch is detected by the usual iodine test. 

Detection of Preservatives. — Formaldehyde and boric acid are tested 
for as in milk. 

Detection of Colors. — See Chapter XVII. The colors used are not 
merely yellows and oranges such as are added to milk, but include also 
reds, greens, and even blues, coal-tar dyes being most commonly employed. 

BUTTER. 

The value of butter as a food depends almost entirely on its fat con- 
tent, although minute quantities of protein and milk sugar are also in- 
cluded in its composition. 

Hence butter is more logically treated in detail under the heading of 

fats. Chapter XIII. 

CHEESE. 

Nature and Composition. — Cheese consists principally of the coagulum 
removed in a mass from milk, which has been curdled by the natural 
souring or by the action of rennet. The separated mass, after being 
compressed, is allowed to undergo certain changes, which constitute the 
ripening or curing, due to the action of micro-organisms and enzymes. 
Cheese is also made from cream, skim milk, and whey. 

Besides nitrogenous bodies, fat, ash (including salt), and water, which 
are its chief constituents, ordinary cheese contains small quantities of lactic 
acid and lactose. The fat in certain varieties also undergoes some changes 
such as the liberation of butyric acid and the lactic acid (at least in Swiss 
cheese) splits up into proprionic and acetic acids. 

During the ripening process, which requires [from a few weeks to 
several months, the characteristic flavor is developed chiefly by the changes 



MILK AND ITS PRODUCTS. 



197 



in the proteins, and the digestibihty of the cheese is improved. The 
nature of these changes is Httle understood, but a variety of complex 
nitrogenous products are formed, which L. L. Van Slyke divides as fol- 
lows: paracasein, unsaturated paracasein lactate, paranuclein, caseoses 
(albumoses), peptones, amides, and am.monia. 

Whey cheese, a product of importance in Scandinavian countries, 
contains lactose as its chief constituent. 

Varieties. — Well-known cheeses of commerce are often named from 
districts, towns, or localities where they originated or are still made. 
They may be classified as cream, whole-milk, or skimmed-milk cheese, 
according to the quality of the product from which they are made, or 
again as hard, medium, or soft, according to whether (i) they are pressed, 
or (2) allowed to drain for days and sometimes weeks without pressure 
to a firm consistency, or (3) are made in the space of a few hours, being 
quickly drained on a sieve by hand pressure. 

Cheddar Cheese, which is the common cheese of the United States 
(though originally made some 250 years ago in England and still made 
there), is a type of the hard cheese. Stilton, an English cheese, Emmen- 
thal and Gruyere, Swiss cheeses; Edam, a Dutch cheese, and Pineapple, 
an American cheese, belong to the hard class, while Camembert, Brie and 
Neufchatel, French cheeses, also Limburger and Brick cheeses are repre- 
sentatives of the soft class. Roquefort, made originally from ewe's milk 
in the French town of that name, and ripened in caves in the mountains, 
and Gorgonzola, an Italian cheese resembling Roquefort, are char- 
acterized by the streaks of green mold. In Norway a sweet cheese is made 
from goat's milk and whey. 

The following table, compiled by Woll,* shows the average composition 
of various cheeses of commerce, both foreign and domestic : 



Cheddar 

Cheshire 

Stilton 

Brie 

Neufchatel 

Roquefort 

Edam 

Swiss 

Full cream, mean of 143 analyses. 



Water. 



Per Gem 
34-3^ 
32. 



Casein. 



Per Cent. 
26.38 

32.5-1 
28.85 
I?. 18 
14.60 
27.63 
24.06 
24.44 
25-35 



Fat. 



Sugar. 



Per Ctnt. 
32.71 
26.06 

35-39 
25.12 
33-70 
33-16 
30. 26 
37-40 
30.25 



Per Cent 
2-95 
4-53 
1-59 
1-94 
4-24 
2.00 
4.60 

2.03 



Ash. 



Per Cent. 
358 
4.31 
3.83 
5.41 
2.99 
6.01 
4.90 
2.36 
4.07 



Dairy Calendar, p. 223. 



198 



FOOD INSPECTION AND ANALYSIS. 



Van Slyke has furnished the following analysis of the nitrogen com- 
pounds in a sample of normal American Cheddar cheese six months old 
and cured at 60° F. : 



Per Cent 

N in 
Cheese. 


Per Cent 
Water- 
soluble N. 


Per Cent 

Nas 

Paranucelin. 


Per Cent 

N as 
Caseoses. 


Per Cent 

N as 
Peptones. 


Per Cent 

N as 
Amides. 


Per Cent 

N as 
Ammonia. 


3.80 


1.46 


0.14 


0.22 


0.18 


0.79 


0.13 



U. S. standards.* — Cheese is the sound, solid, and ripened product 
made from milk or cream by coagulating the casein thereof with rennet 
or lactic acid, with or without the addition of ripening ferments and 
seasoning, and contains, in the water-free substance, not less than 50% 
of milk fat. By act of Congress, approved June 6, 1896, cheese may 
also contain added coloring matter. 

Skim-milk Cheese is defined the same as cheese except that it is made 
from skim milk, and no minimum percentage of fat in the water-free 
substance is specified. 

Adulteration. — Cheese is commonly adulterated in two ways: first, 
by the partial or total substitution for the milk fat of a foreign fat, as 
oleomargarine or lard, and, second, by using skimmed milk as a mate- 
rial for its manufacture. 

In many localities a standard percentage for fat in cheese is fixed by 
law, as in the case of the U. S. standard noted above, all samples falling 
below that standard, unless sold as skim-milk cheese, being deemed adul- 
terated. 

Some states have specific standards for varying grades of cheese, 
classified as to their fat content. Thus under the Pennsylvania law f 
cheese is divided into five grades, as follows: 

Full-cream cheese must contain not less than 32% butter fat. 

Three-fourths cream cheese must contain not less than 2\% butter fat. 

One-half cream cheese must contain not less than 16% butter fat. 

One-fourth cream cheese must contain not less than 8% butter fat. 

All cheese having less than 8% fat must be branded " Skimmed Cheese." 

The term " full cream " as applied to cheese made from whole milk, 
although quite generally used and legalized by certain state laws, is mis- 
leading in view of the fact that true cream cheese is on the market. 



* U. S. Dept. of Agric, Off. of Sec, Circ. 19. 
t Penn. Laws, 1901, Act. 95, p. 128. 



MILK AND ITS PRODUCTS. 



199 



The following analyses by Leach illustrate the difference in composition 
between whole-milk and skim-milk cheese: 



Varieties of Cheese. 



Cream (soft) 

Whole milk (hard) 

Whole milk (soft) 

Skimmed milk (soft) 

Centrifugally skimmed milk (soft) 



Water. 


Fat. 


Protein.* 


Ash. 


37 63 


47.40 


13.70 


1.27 


21.89 


38.00 


37-71 


2.40 


55-95 


24.00 


16.49 


3-56 


62. 17 


15.20 


21.36 


1.27 


72.80 


2.00 


23-52 


1.68 



Fuel Value 
per Pound. 



2255 
2305 
1320 

1039 

522 



* By difference. 

" Filled cheese " is the common name for a product in which a foreign 
fat, such as oleo oil or lard, has been used. Formerly filled cheese was made 
in the United States for the export trade but owing to drastic laws it is 
now practically unknown. 

ANALYSIS OF CHEESE. 

Sampling. — If the cheese is spherical or drum-shaped, cut a narrow, 
wedge-shaped segment, reaching from the circumference to the center, if 
brick shaped, cut a thin slice through the middle; the rind may be included 
in the sample or rejected according to the purpose of the analysis. The 
sample is prepared for analysis by chopping, grating, or kneading until 
uniform, taking care to weigh before and after the treatment if loss of mois- 
ture is sustained. 

A less accurate, but for many purposes quite satisfactory, method of 
sampling is to remove cores from different parts of the cheese with a trier 
using the rind to stop up the holes. By this procedure the cheese is not 
materially damaged. 

Determination of Water. — Dry 5 grams of the sample in a flat-bottomed 
metal dish 5 cm. in diameter in a boiling-water oven until the weight is 
practically constant. If ash is subsecjuently to be determined in the same 
portion a platinum or porcelain dish must be used. 

Winton* has found that reasonably constant weight is obtained in drying 
American full cream and skim -milk cheese only after 12 to 18 hours while 
in drying Roquefort losses, evidently other than water, continued for days. 
For practical purposes drying for 12 hours is sufficient. 

Determination of Fat. — Lythgoe's Modified Babcock Metlmd. — Weigh 
accurately about 6 grams of the sample in a tared beaker. Add 10 cc. 
of boiling water, and stir with a rod till the cheese softens and an even 



■ U. S. Dept. of Agric, Div. of Chem., Bui. 35, 1892, p. 13. 



200 FOOD INSPECTION AND ANALYSIS. 

emulsion is formed, preferably adding a few drops of strong ammonia to 
aid in the softening and emulsionizing, and keeping the beaker in hot 
water till the emulsion is tolerably complete and free from lumps. 

If the sample is a full-cream cheese, which is usually evident from 
its taste and appearance, a Babcock cream-bottle is employed. The 
contents of the beaker, after cooling, are transferred to the test-bottle 
as follows: Add to the beaker about half of the 17.6 cc. of sulphuric acid 
regularly used for the test, stir with the rod and pour carefully into the 
bottle, using the remainder of the acid in two portions for washing out 
the beaker. Finally proceed as in the regular Babcock test for milk. 
Multiply the fat reading by 18 and divide by the weight of the sample 
taken to obtain the per cent of fat. 

Shorfs Metlwd.^ — Grind to a uniform powder 2 to 5 grams of the 
sample, and about twice its weight of anhydrous copper sulphate. Place 
a layer of anhydrous copper sulphate about 2 cm. thick on the bottom 
of the inner tube of a Johnson or Knorr extractor, add the ground mix- 
ture, and rinse the mortar first with a little anhydrous copper sulphate 
and finally with ether. Extract for 16 hours, evaporate the ether from 
the extraction-flask, and dry the fat in a boiling-water oven to constant 
weight. 

Werner-Schmidt Method. — Boil 2 to 3 grams of the sample in the 
Werner-Schmidt tube (p. 126) with 5 cc. of water and 10 cc. of concen- 
trated hydrochloric acid till, with constant shaking, all but the fat is 
dissolved. Cool, add 25 cc. of ether, and shake the tube well. Draw 
off as much as possible of the ether, after separation, in the usual manner, 
and extract with four or five additional portions of the solvent. 

Distil off the ether from the combined extractions, and weigh the fat. 

Determination of Total Protein. — Calculate from the nitrogen, 
determined by the Kjeldahl or Gunning method on i to 2 grams of the sam- 
ple, using the factor 6.38, Van Slyke adds a piece of copper sulphate the 
size of a pea during the digestion. 

Separation and Determination of Nitrogen Compounds. — Methods of 
Van Slyke.'\ — Twenty-five grams of the sample are mixed in a porcelain 
mortar with an equal volume of clear quartz sand. Transfer the mix- 
ture to a 450-cc. Erlenmeyer flask, add about 100 cc. of water at 50° C, 
and keep the temperature at 50° to 55° C. for half an hour with frequent 
shaking. Decant the liquid through an absorbent-cotton filter into a 

* U. S. Dept. of Agric, Div. of Chem., Bui. 35, pp. 15, 17, 225. 
t Van Slyke, N. Y. Exp. Station, Bui. 215. 



MILK AND ITS PRODUCTS. 201 

500-cc. graduated flask. Treat the residue with repeated portions of 
100 cc. each of water, heating, shaking, and decanting as above till the 
filtrate, or water extract, at room temperature amounts to just 500 cc. 
exclusive of the fat floating on top, and use aliquot parts of this water 
extract for the various determinations. 

Water-soluble Nitrogen. — Determine the nitrogen by the Gunning 
method in 50 cc. of the above water extract, corresponding to 2.5 grams 
of cheese. 

Nitrogen as Paranuclein.— Add 5 cc. of a 1% solution of hydrochloric 
acid to 100 cc. of the above water extract (corresponding to 5 grams of 
cheese), and keep the temperature at 50° to 55° till the separation is com- 
plete, as shown by a clear supernatant liquid. Filter, wash the precipi- 
tate with water, and determine the nitrogen therein by the Gunning 
method. 

Nitrogen as Coagulable P^o/e/w.— Neutralize the filtrate from the 
preceding determination with dilute potassium hydroxide, and heat at 
the temperature of boiling water till the coagulum,* if any, settles com- 
pletely. Filter, wash the precipitate, and determine the nitrogen therein. 

Nitrogen as Caseoses. — Treat the filtrate from the preceding with i cc. 
of 50% sulphuric acid saturated with C. P. zinc sulphate, and warm to 
about 70° C. till the casesoses settle out completely. Cool, filter, wash 
with a saturated solution of zinc sulphate acidified with sulphuric acid, 
and determine the nitrogen in the precipitate. 

Nitrogen as Amino Acids and Peptones. — Place 100 cc. of the water 
extract in a 250-cc. graduated flask, add i gram of sodium chloride 
and a solution containing 12% of tannin, till the addition of a drop to 
the clear supernatant liquid does not further precipitate. Dilute to the 
250-cc. mark, shake, pour upon a dry filter, and determine the nitrogen 
in 50 cc. of the filtrate, which gives the amount of nitrogen in the amino-acid 
and ammonia compounds. Deduct from this the amount of nitrogen as 
ammonia separately determined, and the difference is the amino-nitrogen. 

Nitrogen as peptones is obtained by subtracting the sum of the amounts 
of nitrogen as paranuclein, coagulable proteins, caseoses, amino-bodies, 
and ammonia from the total nitrogen in the water extract. 

Nitrogen as Ammonia. — Distil ico cc. of the filtrate from the above 
tannin-salt precipitation into standardized acid, and titrate in the usual 
manner. 



According to Van Slyke a precipitate at this point is rare in cheese. 



202 FOOD INSPECTION AND ANALYSIS. 

Nitrogen as Paracasein Lactate. — Treat the residue insoluble in water 
in obtaining the water extract, with several portions of a 5% solution 
of sodium chloride, to form a 500-cc. salt extract of the same, in an 
analogous manner to that employed in preparing the water extract. 
Determine the nitrogen in an aliquot part of this salt extract. 

Determination of Lactose. — Rub up ten grams of the sample with 
water at 40 to 50° C, and decant onto a filter. Repeat the operation 
until the filtrate measures 100 cc. Determine lactose in an aliquot by one 
of the methods described under milk. 

Except in the case of whey cheese, lactose is present only in minute 
amount if at all. Commonly lactose, lactic acid, and other minor consti- 
tuents are determined by difference subtracting the sum of the water, 
fat, total protein, and total ash from 100. 

Determination of Ash. — Ignite at dull redness 5 grams of the cheese 
in a tared platinum or porcelain dish until a white ash is obtained, using 
preferably a mufHe furnace, cool in a desiccator, and weigh. 

Determination of Sodium Chloride. — Treat the ash with water acidified 
with nitric acid, filter, wash, and precipitate the chlorine in the filtrate 
with silver nitrate solution. Filter on a Gooch crucible, heat cautiously 
to melting, and weigh. Calculate the equivalent sodium chloride. 

The chlorine may also be determined volumetrically, without filtering, 
by Volhard's method. 

Acidity. — Jensen and Plattner Method.'^ — Rub up 10 grams of the 
sample in a mortar with water at 40 to 50° C, and decant onto a filter. 
Repeat the rubbing and decanting until the filtrate measures 100 cc. 
Titrate an aliquot with N/io sodium hydroxide, using phenolphthalein as 
indicator; i cc. =0.009 gram lactic acid. 

Although the acidity is usually calculated as lactic acid, other acids or 
acid-reacting substances may be present. 

Detection of Foreign Fat. — The cheese fat, separated in the manner 
described below, is subjected to the various processes detailed under 
butter, in precisely the same way, the fat of cheese being identical with 
that of butter. The most ready means for judging its purity consists 
in determining the refraction with the butyro-refractometcr, and the 
Rcichert number. 

The distinction of cow's milk from goat's milk fat is best accomplished, 
according to Hals and Sunde f by the ratio of the Polenske to the Reichert- 

* Zeits. Unters. Nahr. Genussm., 12, 1906, p. 193.' 
t Tidskr. Kem. Farm. Ter., 5, 1908, p. 8. 



MILK AND ITS PRODUCTS. 203 

Meissl number which for goat's milk is about i : 5 and for cow's milk 
I : 8 to I : 9. 

Separation of the Fat for Examination. — Place a quantity, say 25 
grams, of the finely divided sample in a large Erlenmeyer flask, add about 
100 cc. of petroleum ether, cork the flask and allow it to stand for several 
hours with frequent shaking. Decant the petroleum ether through a 
filter, evaporate off the solvent by the aid of heat, and the residue will 
be found to consist of nearly pure fat. 

Or, wrap a sufficient portion of the finely divided sample in a muslin 
cloth, place this in a dish, and heat on the water-bath. The fat which 
runs out is afterward filtered and dried at 100°. 

Sufficient cheese fat may usually be obtained for the refractometer 
reading from the neck of the test-bottle, after completing the Babcock 
test, and, usually (except in the case of skimmed-milk cheese), for the 
Reichert number. 

Detection of Skimmed-milk Cheese. — In a cream cheese the fat 
should greatly exceed the protein; in a whole-milk cheese the per cent 
of fat should at least equal that of the protein, and is generally in excess. 
If the fat is considerably less than the protein, the cheese has undoubtedly 
been made from skimmed milk. The analyses on page 199 illustrate 
these points. 

PROTEIN PREPARATIONS. 

Casein is the basis of a variety of preparations, some of which are 
intended for the use of invalids and people of weak digestion, and others, 
from their compactness, for travellers and campers. Among these foods 
are the following: 

Nutrose. — This is a caseinate of sodium formed by the action of the 
alkali upon dried casein. It is soluble in water. 

Eucasin is a caseinate of ammonium, a soluble powder somewhat 
similar to nutrose. 

Plasmon. — This is a yellowish powder, prepared by treatment with 
sodium bicarbonate of the curd precipitated from skimmed milk. The 
compound is kneaded in an atmosphere of carbon dioxide, and reduced 
to a soluble powder. 

The following analysis of plasmon was made by Woods and Merrill:* 

* Maine Agric. Exp. Sta., Bui. 178, p. loi. 



204 



FOOD INSPECTION AND ANALYSIS. 



Water. 


Protein. 


Fat. 


Carbohydrates. 


Ash. 


Fuel Value. 


8.5 75-0 


0.2 


8.9 


7-4 


2044 



Hogg^s Protein Nerve Food is practically the same as sanatogen, 

Sanose. — This is a powder. It contains 80% of pure casein and 
20% of albumose obtained from the white of egg. The powder possesses 
a slight taste and an odor suggestive of milk. By briskly stirring the powder 
with water, an emulsion may be made much resembling milk, but on 
standing it soon breaks up. 

Sanatogen is a grayish-white, tasteless powder, containing 95% of 
casein and 5% sodium glycero-phosphate. When treated with cold 
water it swells, forming on heating a milk-like emulsion. 

Vitafer and Cibrola are similar to sanatogen but contain more glycero- 
phosphate and less casein. 

Lactalbumin in dried and powdered form, like lactose, is obtained 
from whey. 



1 



CHAPTER VIII. 

FLESH FOODS. 

MEAT. 

General Structure and Composition. — Meat is structurally made up of 
muscle fibers, held together by connective tissue, through which blood vessels, 
nerves, and usually fat cells are more or less abundantly distributed. Each 
muscle fiber has a sheath or covering known as sarcolemma inclosing 
the meat juices, which are solutions in water of proteins, non-protein 
nitrogenous extractives, and salts. 

The insoluble portion of the living muscle (connective tissue, sarco- 
lemma, etc.) is known as stroma, the soluble portion constituting about 
60% by weight as obtained by high pressure, as plasma. After rigor 
mortis sets in certain soluble constituents coagulate and the liquid obtained 
by pressure is a serum analogous to the serum separated from blood clot. 

Nitrogen compounds constitute by far the most abundant and im- 
portant portion of the substance of lean meat. Carbohydrates are almost 
entirely lacking, the small amount of glycogen and muscle sugar together 
constituting rarely more than i per cent, 

TJie Nitrogenous Substances consist of proteins and so-called extrac- 
tives. The stroma proteins include the elastin and collagen of connective 
tissue and the proteins of the sarcolemma which are imperfectly under- 
stood. Formerly myosin, a globulin-like substance, was considered the 
chief protein of the plasma but now it is believed that myogen, an albumin, 
is a more- abundant constituent. Peptones and proteoses are formed in 
meat after death by enzymic action. The extractives of chief interest to 
the analyst are creatine, creatinine, carnosine, carnitine, methyl guanidine, 
and the purine bases xanthine, hypoxanthine, guanine, and adenine. 

The Fats are considered in Chapters III and XIII. 

Carbohydrates. — 

Glycogen (CeHioOs), sometimes called animal starch, is a white, amor- 
phous, tasteless, and colorless substance, when pure, much resembling 
starch. It is soluble in water, forming an opalescent solution, and is 
insoluble in ether and nearly so in cold alcohol. With iodine a port- wine 
color is produced, which disappears on heating and reappears on cooling. 

205 



206 



FOOD INSPECTION AND ANALYSIS. 



Glycogen is strongly dextro-rotatory and converted into dextrose by boiling 
with dilute mineral acid. It occurs in small amount in all fresh muscle, 
particularly that of the horse, and in larger amount in liver, but disappears 
to a large extent on aging. 

Muscle Sugar is either entirely absent in the living muscle, or exists 
in traces only. After death it is formed presumably from the glycogen, 
and exists in a very minute quantity, probably as dextrose. 

Inosite (C6H12O6+H2O) is found in traces in the muscular substance 
and animal organs. It is a protoplasmic substance related to the carbo- 
hydrates. 

The Acids developed in meat consist chiefly of lactic. Succinic^ 
inosinic, and uric acids are among the other acids present in small amount. 

The Ash of meat consists, like that of plants, of phosphates, sulphates, 
and chlorides of potassium, sodium, calcium, magnesium, and iron together 
with traces of other inorganic constituents. In the meat itself some of the 
inorganic elements exist in organic combination. 

The approximate proportions in which the chief constituents are present 
in meat is thus shown by Konig : 

Water 75° to 77.0 

Sarcolemma (muscle fiber) 13.0 to 18.0 

Connective tissue 2.0 to 5.0 

Albumin (coagulable protein) 0.6 to 4.0 

Creatine 0.07 to o . 34 

Hypoxanthine' 0.01 to 0.03 

Creatinine i 

Xanthine tt j ^ • 1 

T . . ., > Undetermined 

Inosmic acid 

Uric acid -' 

Urea o . 01 to o. 03 

0.05 to 3.5 

Lactic acid o . 05 to 0.07 

Butyric acid "j 

A^^t^^^"d Undetermined 

Formic acid 

Inosite ■^ 

Glycogen 0.3 to o. s 

Salts 0.8 to 1 . 8 

Composed of: Potash 0.40 to o. 50 

Soda 0.02 to o 08 

Lime o.oi to o 07 

Magnesia 0.02 to 0.05 

Oxide of iron o . 003 to o. 01 

Phosphoric acid o. 40 to o. 50 

Sulphuric acid o . 003 to o . 04 

Chlorine o.oi to p. 07 



Nitrogenized compounds. 



Fat. 



Other nitrogen-free compounds . 



FLESH FOODS. 207 

Proximate Composition of the Commoner Meats. — The chief char- 
acteristics of the flesh of various animals are in the main very similar, 
whatever the nature of the animal. So true is this, indeed, that it is 
usually impossible from a chemical analysis to distinguish a particular kind 
of flesh when mixed with that of other animals in finely divided meat 
preparations, such as sausages, potted and deviled meats, and the like. 

The average composition of the commoner cuts of beef, veal, mutton, 
lamb, and pork, as well as of fowl and game, is shown in the following 
tables, compiled from the work of Atwater and Bryant *, the accompanying 
diagrams serving to locate, in the case of ordinary meats, the portion of 
the animal from which the meat is taken. 

Constants of Fat. — These as found by Bigelow are given in the table 
on page 212. 

Characteristics of Sound Meat. — The reaction of meat should be acid. 
If neutral or alkaline, decomposition is indicated, except that alkalinity 
may be due to the use of alkaline salts as preservatives. 

Letheby t gives the following characteristics of sound, fresh meat. In 
color it is neither pale pink nor deep purple, the former indicating that 
the animal was affected with some disease, and the latter that it died a 
natural death, and was not slaughtered. In appearance it is marbled, 
due to the presence of small veins of fat distributed among the muscles. 
In consistency it is firm and elastic to the touch, and should hardly moisten 
the finger; a wet, sodden, or flabby consistency with a jelly-like fat is 
indicative of bad meat. As to odor, it is practically free; whatever odor 
there is should not be disagreeable ; a sickly or cadaverous smell is indica- 
tive of diseased meat. After standing for a day or so, it should not become 
wet, but on the contrary should grow drier. When dried at 100° C. it 
should not lose more than 70 to 74 per cent in weight; unsound meat 
frequently loses 80% or more. It should shrink very little in cooling. 

Inspection of Meat. — While carefully drawn laws exist almost every- 
where relating to the sale of meat, and government inspectors are ap- 
pointed to carry out the requirements of the laws, yet in this country there 
is undoubtedly some meat unfit for food on the market, owing to the 
small number of inspectors, and the consequent comparative safety with 
which unscrupulous dealers may sell meats forbidden by law and escape 
detection. The inspection of meats and fish under municipal ordinances 
is not always carried out as thoroughly as might be desired. 

* U. S. Dept. of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed.). 
t Lectures on Food, p. 210. 



208 



FOOD INSPECTION AND ANALYSIS. 




1. Neck 

2. Chack 

3. Ribs 

i. Shoulder clod 
6. Fore shank 

6. Brisket 

7. Cross ribs 

8. Plate 



9. Navel 

10. Loin 

11. Flank 

12. Rump 

13. Round 

14. Second cut round 
10. Hind shank 



Fig. 56.— Diagram Showing Cuts of Beef. 
COMPOSITION OF BEEF. 




Cut. 



Num- 
ber of 
Anal- 
yses. 



Refuse 



Water. 



Protein. 



N < 
6.25. 



By 

Differ- 



Fat. 



Ash. 



Fuel 
Value 

per 
Pound. 
Cals. 



Ribs: 



Chuck: Lean — 
Medium- 
Fat— 
Lean — 
Medium- 
Fat— 

Loin: Lean — 
Medium- 
Fat— 

Rump: Lean — 
Medium- 
Fat— 

Round: Lean — 
Medium- 
Fat— 



edible portion. 

as purchased, 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased. . 

edible portion. 

as purchased. . 

edible portion. 

as purchased. . 
-edible portion. 

as purchased . . 

edible portion. 

as purchased . . 



19-5 



4 

4 
4 
3 
6 
6 
15 
15 
9 



32 
32 
6 
6 
4 
3 



15.2 
14.7 



22.6 



20.8 



13 -I 
13-3 



14.0 



20.7 

2.^.0 



i.I 



7-2 

12.0 



8.2 

6.6 
II. 9 

10. 1 
18.8 

15-9 
9.8 

9-3 
26.6 

21 .2 
35-6 



30 



20.2 

17-.5 
27.6 
24.8 
13-7 

11. 

•25-5 
20.2 

35-7 
27.6 

7-9 

7-3 

13.6 

12.8 

19-S 

16. 1 



0.8 
0.9 
0.8 
0.9 
0.7 
0.8 
0.7 
0.9 
0.7 
0.7 
0.6 
i.o 
0.9 
i.o 

0.9 
0.9 
0.8 

I.o 

0.9 
0.9 
0.7 
0.8 
0.6 



0.8 



720 

580 
865 

735 

"35 

965 

790 

675 
1450 
"55 
1780 

1525 
900 

785 

1 190 

1040 

1490 

1305 

965 

820 

1400 

mo 

1820 

1405 

730 

670 

950 

895 

1 185 

1005 



FLESH FOODS. 



209 




'^^i^^fjiM^mi^ 



l.Neck 

2. Chuck 

3. Shoulder 

4. Fore shank 

5. Breast 



^^.//.. 



^|^£(lfeyii'/'^ 



6. Ribs 

7 . Loin 

8. Flank 

9. Leg 

10. Hind shank 




Fig. 57. — ^Diagram Showing Cuts of Veal. 



COMPOSITION OF VEAL. 





Num- 
ber of 
Anal- 
yses. 


Refuse. 






Protein. 


Fat. 


Ash. 


Fuel 
Value 

per 
Pound 

Cals. 


Cut. 


Water. 


NX 
6.25. 


By 
Differ- 
ence. 


Chuck: Lean — edible portion. . 

as purchased 

Medium — edible portion . . 

as purchased.. . 

Ribs: Medium — edible portion. . 

as purchased — 

Fat — edible portion. . 

as purchased 

Loin: Lean — edible portion. . 

as purchased.. . 

Medium — edible portion.. 

as purchased.. . 

Fat — edible portion . . 

as purchased 

Leg: Lean — edible portion. . 

as purchased 

Medium — edible portion., 
as purchased 


I 
I 
6 
6 
9 
9 
3 
3 
5 
5 
6 
6 
2 
2 
9 
9 
10 

9 


19.0 
18.9 
25-3 
24-3 
22.0 

"ih'.y 
9.1 
14.2 


76. 2 




20.6 
16.7 
19.2 
15-6 
20.1 

15-0 
18.8 
14.2 
19.9 
15.6 
19.2 
16.0 
18. 5 

15-1 
21.2 

19-3 
19.8 
16.9 


1.9 

1.6 

6.5 

5-2 

6.1 

4.6 

19-3 

14-S 

5-6 

4.4 

10.8 

9.0 

18.9 

15-4 

4-1 

3-7 

9.0 

7-9 


1.2 

0.9 

I.O 

0.8 
I.I 
0.8 
1.0 
0.8 
1.2 
0.9 
I 
0.9 
1.0 
0.8 
1.2 
I.I 
1.2 
0.9 


465 
380 
640 

515 
640 
480 

1 1 60 
87s 
61S 
480 
82s 
690 

1 145 
935 
570 
520 

755 
620 


61 

73 
59 
72 
54 
60 
46 
73 
57 
69 

57 
61 

50 
73 
66 
70 
60 


8 
3 
5 
7 
3 
9 
2 

3 

I 

6 
6 
4 
5 
8 

I 






19 
16 
20 

15 
18 

14 
20 

15 
19 
16 
18 

15 
21 

19 
20 

15 


7 


7 

5 
7 
2 

4 
9 
9 
6 

7 
3 
3 
4 
2 

5 



210 



FOOD INSPECTION AND ANALYSIS. 




1 . Neck 

2. Chuck 

3. Shoulder 
i. Flank 

5 ■ Loin 
6. Leg 




Fig. 58. — Diagram Showing Cuts of Mutton. 
COMPOSITION OF MUTTON AND LAMB, 





Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 


Fat. 


Ash. 


Fuel 
Value 

per 
Pound, 
Cals, 


Cut. 


NX 
6.25. 


By 

Differ- 
ence: 


Mutton. 

Chuck: Lean — edible portion . . 

as purchased. . . 

Medium — edible portion . . 

as purchased. . . 

Fat — edible portion. . 

as purchased 

Loin: Medium — edible portion. . 

as purchased 

Fat — edible portion. . 

as purchased — 

Flank: Medium — edible portion. . 

as purchased 

Leg: Lean — edible portion. . 

as purchased 

Medium — edible portion . . 

as purchased 

Lamb. 
Chuck: edible portion . . 

as purchased 

Leg: Medium — edible portion . . 

as purchased 

Fat — edible portion . . 

as purchased 

Loin: edible portion. . 
as purchased... 


I 
I 
6 
6 
2 
2 

13 

12 

3 
3 
8 
2 
3 
3 
II 
II 

I 
I 
2 
2 

I 
I 
4 
4 


19-5 
21.3 

"ih'.'s' 

16.0 

II. 7 

9-9 

18.4 

19. 1 
17.4 
13-4 

"2;:8' 


64.7 
52-1 
50-9 
39-9 
40.6 
33-8 
50.2 
42.0 
43-3 
38-3 
46.2 

39-0 
67.4 
56-1 
62.8 
51-2 

56.2 
45-5 
63-9 
52-9 
54-6 

47-3 
53-1 
45-3 


17.8 
14-3 
151 
II. 9 

13-9 
II. 6 
16.0 
13-5 
14-7 
13-0 
15.2 

13-8 
19.8 
16.5 
18.S 
15-1 

19. 1 

iS-4 
19.2 

15-9 
18.3 

15.8 
18.7 
16.0 


18 
14 
14 
11 

13 
II 

15 
13 
14 
12 

14 
13 
19 
15 
18 

14 

19 
15 
18 

15 
17 
14 

17- 
IS- 


.1 

•5 
.6 

■5 
■7 
•5 
•9 

2 

5 
8 
6 
I 

9 

2 

9 

2 
5 
5 
2 
I 
8 
6 



16.3 

13-I 
33-6 
26.7 

44-9 
37-5 
33-'^ 
28.3 
41.7 
36.8 
38.3 
36-9 
12.4 
10.3 
18.0 
14.7 

23.6 
19. 1 
16-S 
13-6 
27.4 
23-7 
28.3 
24-1 


0.9 
0.8 
0.9 
0.6 
0.8 
0.7 
0.8 
0.7 
0.8 

°-l 
0.7 

0.6 

I.I 

0.9 

I.O 

0.8 

1.0 
0.8 
I.I 
0.9 
0.9 
0-8 
1.0 
0.8 


1020 
820 
1700 
1350 
2155 
1800 

1695 

1445 

203s 

1795 

1900 

1815 

890 

740 

1 105 

900 

1350 
1090 

loss 
870 

1 495 
1295 
1540 

131S 



FLESH FOODS. 



211 




""'^"^^MWl'n'i 



''III ^i'^r^,i''Ti'''iiiil'iiiiO 



1. Head. 
2 Shoulder. 

3. Back. 

4. Middle cut. 

5. BeUy. 

6. Ham. 
Y. Ribs. 
8. Loin. 



Fig. 59- — Diagram Showing Cuts of Pork. 
COMPOSITION OF PORK, POULTRY, AND GAME. 






Num- 
ber of 
Anal- 
yses. 


Refuse. 


Water. 


Protein. 






Fuel 


Cut. 


NX 
6.25. 


By 
Differ- 
ence. 


Fat. 


Ash. 


Value 

per 
Pound 
Cals. 


Pork. 
Shoulder: edible portion. . 

as purchased 

Loin: Lean — edible portion. . 

as purchased 

Fat — edible portion . . 

as purchased. . . 

Ham: Lean — edible portion. . 

as purchased.. . 

Fat — edible portion . . 

as purchased 

POXJLTEY AND GaME. 

Chicken: edible portion . . 

as purchased 

Fowl: edible portion . . 

as purchased... 
Goose: edible portion . . 

as purchased... 
Turkey: edible portion . . 

as purchased 

Quail: as purchased 


19 

19 

I 

I 
4 
4 
2 
2 
5 
5 

3 
3 

26 
26 

I 
I 
3 
3 

1 


12.4 
23-5 

0.-9 
13.2 

41.6 

25-9 
17.6 

22.7 


51.2 

44-9 
60.3 
46.1 
41.8 
34-8 
60.0 
59-4 
38-7 
33-6 

74-8 
43-7 
63-7 
47-1 
46.7 

38-5 
55-5 
42.4 
66.9 


13-3 
12.0 
20.3 
15-5 
14-S 
II. 9 
25.0 
24.8 
12.4 
10.7 

21-5 

12.8 

19-3 
13-7 
16.3 

13-4 
21. 1 
16. 1 
21.8 


13-8 
12.2 
19.7 
15-I 
13-I 
10.9 

24-3 

24.2 

10.6 

9.2 

21.6 
12.6 
19.0 
14.0 
16.3 

13-4 
20.6 

15-7 


34.2 
29.8 
19.0 

14-5 
44-4 
37-2 
14.4 
14.2 
50.0 
43-5 

2-5 

1.4 
16.3 
12.3 
36.2 
29.8 
22.9 
18.4 

8.0 


0.8 
0.7 

I.O 

0.8 
0.7 
0.6 
1-3 
1-3 
0.1 

o-S 

I.I 

0.7 
1.0 
0.7 
0.8 
0.7 
1.0 
0.8 
1-7 


1690 

1480 

1 180 

900 

2145 
1790 

1075 
1060 

2345 
2035 

505 
29s 

1045 
775 

1830 

1505 
1360 

1075 
775 



212 



FOOD INSPECTION AND ANALYSIS. 







00 O vO 


M O in 
NO t^ vo 








On m N 

On NO NO 


■* moo 
H CO On 


00 lO Tt 


rf O On 

lO 0) CO 


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d d d 




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ro fO t-O 




■^ LD •* 


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'i- Tj- ^ 




v • 








t^ •^OO 


O M 


M 00 O 


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NO 00 lo 




^11 


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ro uo lo 




ro -^ H 


00 l^ •* 


On J^ <N 


lo CO 


r^NO N 






N -i- On 




M vr-,00 


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O -i-NO 


lONO lO 


O 01 00 




i< 


Q\ O^ On 


On OnOO 




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On OnOO 


On OnOO 


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On OnOO 




a • 




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w NO On 


CO rO On 


r~- O M 


H N lO 


O O O 




-§1 
1< 


d d d 


NO NO O 

d H d 




fO t^ >-i 


OnnO m 


aNO ^ 


lo On M 


t^ r^ M 




M M O 


O <N O 


O 01 o 


GOO 


O M 




i^Si 


CO O O 


<^ O 
















11 § 




NO M 




M lONO 


ro «^ On 


CO m M 


00 OnnO 


CO O ^ 




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On M On 




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On O r^ 


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M-| 


M <N M 


M N M 




O (N M 






M Ht M 






«s 


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t^NO On 


M lo On •+ O Tf 


00 M m 


00 NO CO 


w ■* O 


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» 


-c a 




CS 00 t^ 


rf t^ O 


NO t^ M 


t^oo 00 


00 CO r^ 


NO NO r-~ 


lO CO On 


r/^ 


Tj- LO fO 


Tj- ^ rO 


lO LO lO NO t^NO 


ionO ■* 


Tt-NO CO 


t^oo NO 


IONO CO 


^ 


'^z 


















U 
1— t 


M . 




O >n On 


O O 


<N O O 


rn O m 


r- O 


NO lO O 


CO LT) 


< 
























M -t ON 


NO On IN 


r^ uo M 


O ^ t-~ 


NO CO ID 


OnnO 01 


01 CO 01 


^ 3 




ro fO N 


C) M (N 


M M M 


Cl CJ w 


C) CO M 


W CO M 


01 CO w 


Pi 

< 


a^ 


















u . 






c<->nO r^ r^ W-) 0) 


t^ mNO 


CO Tl- lO 


01 O O 


M lONO 


w 
Pi 


•I.s 


O fONO 


O r^ t^ 


On M r^ On <N) r^ 


«^ O ro 


UO M NO 


w" 4cd 


vo M t^ 


"C o 


Tt Tj- <r> 


■* ■* fO 


ro ■* r^ N ro w 


CNi ro N 


CO •* P< 


CO CO 0« 


oo Tj- 01 


Uh 


s^- 


















H 


«4-t 




00 M On 


t-~ On On ro w lO 


VOOO NO 


00 r^ CO 


r^ •* O 


O O On 


< 


i-S 




M ro O 


P) T^ O. t^NO « 


M 'too 


« r^ r^ 


CO t-~ On 


01 NO LO 








NO NO w-> vo r^NO 


NO NO lO 


NO NO lO 


NO NO LO 


VO NO LO 


W 


Tf rf ■* 


Tt ^ ^ 


■<t •* ■* ■* ■^ Tt 


't 't ■* 


■*'*■* 


^ ■* ■* 


'*'*•'* 


^ 


"0 4) 0=*5 




M IH M 


M M M 


M M M 


W M M 


M M M 


M M M 


tH M M 


ft 






00 


















00 >^ O 


On O r^ 


M IT) C 


r*^ u-> N 


■* N O 


O O N 


r^ m O 


NO CO 01 
























t; >. £ <u CO 




r<0NO (N 


tOOO 1- 


c^ \0 in 


rooO On 


TfOO J^ 


NO 01 On 


M- O On 


^ 


sl"^!^ 


ir, in -rt 


iO,tr) IT) 


tO lO lO NO 4^ U-) 


m m rt 


\n m -rf 


lonO tJ- 


lONO Tj- 


H 


















slo ; 




w M ro 








On W 00 


cooo O 


lONO CO 


co lO O 


NO O 01 




t^OO NO 








Owe 


rO On NO 


NO N NO 


COOO On 


On lOOO 


r/1 












NO 00 LO 


tONO « 


W-) r^ CO 


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i/-,00 -:t 




00 00 00 

odd 


00 0(5 00 
d d d 








00 00 00 

d d d 


00 oo oo 

odd 


00 00 00 

6 6 6 


00 OO 00 

6 6 6 


00 00 00 

odd 


n 


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r^ 'i-oo 


rONO On 


OnnO r^ 


0> r^ On 


CO vonO 


His 

coo 




ro Tt- N 








NO 00 NO 


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(N On w 


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w 00 


00 NO 


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< 


00 OnOO 

d o 


00 CO 00 

d d d 








On OnOO 

6 6 6 


00 ONOO 

6 6 6 


00 OnoO 

6 6 6 


00 O-OO 

d d d 


00 OnOO 

d d d 


> 




; ; ; 


! ! I 








\ ', ', 






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: s s 




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u 3 3 

fc s s 


m 3 3 


0) =3 b 


o P p 


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<u P p 


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« .5 c 








^se 










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73 




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m 



FLESH FOODS. 213 

Unwholesomeness of Meat may be due to a diseased condition of the 
animal while alive, or to poisonous or injurious toxins developed by 
the action of bacteria after death. In the first case; the diseased conditions 
may be due to temporary causes only, or to the presence of animal parasites, 
such as trichinae in pork, or as the result of pathogenic bacteria, causing 
such serious diseases as tuberculosis, anthrax, glanders, etc. It thus 
requires much skill and judgment on the part of the meat-inspector 
(who should be a trained veterinarian) to correctly pass upon the suit- 
ability for food of the various meats as they appear on the market. Various 
works * on meat inspection give in detail useful data regarding ante- and 
post-mortem examination but anatomical, pathological, and microscop- 
ical details are rarely germane to the work of the public food analyst, 
and will not be treated of in this manual. 

It is also beyond the scope of the present work to treat of the harmful 
toxins developed by bacterial action in meat and fish, causing what is 
known as ptomaine poisoning. The work of detecting and isolating 
such poisons comes within the province of the bacteriologist and biolo- 
gist, rather than that of the chemist, involving many experiments upon 
guinea-pigs, rabbits, or other animals not usually found in the chemist's 
laboratory. It has furthermore been demonstrated by Vaughn and 
Novy t that even when these toxins are present in foods in sufficient 
quantity to produce serious results, very considerable amounts of the 
food must be taken in order to isolate them by chemical means, more, 
in fact, than is usually available for analysis. 

U. S. Standards.l — Standard Meat is any sound, dressed, and properly 
prepared edible part of animals in good health at the time of slaughter. 
The term " animals " as herein used includes not only mammals, but 
fish, fowl, crustaceans, mollusks, and all other animals used as food. 

Standard Fresh Meat is meat from animals recently slaughtered, or 
preserved only by refrigeration. 

Standard Salted, Pickled, and Smoked Meats are unmixed meats pre- 
served by salt, sugar, vinegar, spices, or "^moke, singly or in combination, 
whether in bulk or in packages. 



* Andrews, Flesh Foods; Edelmann (trans, by Mohler and Eichhorn), Textbook of 
Meat Hygiene; Ostertag (trans, by Wilcox), Handbook of Meat Inspection; Robertson, 
Meat and Food Inspection; Vacher, The Food Inspector's Handbook; Walley, A Practical 
Guide to Meat Inspection. 

t Cellular Toxins. 

X U. S. Dept. of Agric, Off. of Sec, Circ. No. 19. 



214 FOOD INSPECTION AND ANALYSIS. 

Standard Manufactured Meats are meats not included in the above 
divisions, whether simple or mixed, whole or comminuted, with or without 
the addition of salt, sugar, vinegar, spices, smoke, oils, or rendered fat, 
if they bear names descriptive of their composition, and when bearing such 
descriptive names, if force or flavoring meats are used, the kind and 
quantity thereof are made known. 

Preservation of Meat. — Raw meat soon begins to decompose, unless 
precautions are taken to destroy, or at least check the growth of putrefying 
bacteria. From earlier times the subjection of meat to extreme cold 
has been practiced in order to enhance its keeping qualities. Bacterial 
growth is inhibited to a greater or less extent by refrigeration, by sub- 
jecting the meat to the various processes of curing, by the use of high 
temperatures and the exclusion of air as in canning, and by the employ- 
ment of antiseptics. 

Cold Storage may consist (i) in actually freezing the meat, in which 
condition it may be kept without decomposition almost indefinitely, until 
finally thawed for use, or (2) in keeping the meat at or near the temperature 
of freezing without actually congealing it, as is done by the use of the 
ordinary refrigerator. The second method, while much less efficacious 
than the first, serves to prevent decomposition for a considerable time. 

Effects of Cold Storage on the Composition of Meat. — Richardson and 
Scherubel * made comparative analyses of beef stored at 2 to 4° C. for a 
week or less and of that held at —11 to —13° C. for various lengths of time 
ranging from a month to over a year and a half. The results of chemical 
analysis, as well as histological and bacterial examination, are practically 
the same in both cases. When stored for some months at 2 to 4° C. with 
or without previous freezing, they found more or less marked increases in 
ammonia, coagulable proteins, albumoses, and meat bases. 

Wright's investigation t with lamb, mutton, and other meats showed no 
bacterial change during storage at freezing temperatures and only slight 
chemical changes. 

Pennington,! in experiments with cold-storage chickens (the history 
of which up to the beginning of storage is unknown), found during storage 
for 14 months or longer a marked increase in certain nitrogenous constitu- 
ents, notably those soluble in cold water and those coagulable, also marked 
changes in the fat, especially the lowering of the iodine number and the 

* Jour. Ind. Eng. Chem., i, 1909, p. 95. 

t Jour. Soc. Chem. Ind., 31, 1912, p. 965. 

X U. S. Dept. of Agric, Bur. of Chem., Bui. 115, 1908. 



' FLESH FOODS. 215 

liberation of large amounts of free fatty acids. Histological and bacterial 
changes were also noted, 

Richardson,* on the other hand, observed with chickens frozen 3 to 
25 months, some variations in composition but no progressive changes of 
any kind. He states " More decomposition developed at room temperature 
(26°) during 24 to 48 hours than when stored below — 5° for 9 years," 

Pennington, Hepburn, St. John, and Witmer,t in experiments with 
poultry held at 23,9° C. for 4 days and at 7.2 to 12.8° for 7 days, in a house- 
hold refrigerator and at 0° for 3 weeks, obtained in all cases an increase of 
amino acids and basic nitrogen and a decrease of proteins, also an increase 
in the acid value of the fat as well as changes in histological structure. 

Curing consists in subjecting the meat to various processes of drying, 
smoking, pickling, corning, etc, or to a combination of these processes. 

Drying. — In simple drying, the meat is subjected to the heat of the sun 
or to artificial heat. Commonly, drying is combined with some other 
method of preservation such as smoking in the case of beef or salting and 
spicing as in the case of certain kinds of sausage. Powders made of desic- 
cated meat are as yet of small importance. 

Smoking. — As commonly practiced with beef, bacon, and ham, the 
meat, which may or may not be first salted or otherwise treated, is exposed 
to the smoke of the burning beech or hickory wood, thus becoming impreg- 
nated with the antiseptic properties of the creosote and pyroligneous acid, 
at the same time being dried by the heat. Treatment with crude pyrolig- 
neous acid, instead of smoking, is also commonly practiced. In some cases 
best results are obtained by a slow smoking at a comparatively low tempera- 
ture, while in others quick, hot smoking is found most efficacious. The 
character of the meat is decidedly changed by smoking, and, according to 
Utescher, smoked meat is always alkaline in reaction. 

Pickling. — The meat may be treated with dry salt and subjected to pres- 
sure, so that the meat juice forms the liquid for the brine, in which it is 
allowed to remain for some time; or, as in the ordinary process of corning, 
the beef is soaked for some days in a strong solution of salt to which a 
little saltpeter (KNO3) has been added. In the process of pickling, the 
salts from the brine slowly diffuse into the interior of the meat by osmosis, 
a part of the soluble albumin passing out into the brine. The effect of the 
saltpeter is to preserve the natural red color of the meat, which by the action 
of salt alone becomes destroyed, or at least impaired. 

* Allen's Coml. Org. Analysis, 4th Ed., 8, p. 426. 
t Jour. Biol. Chem., 29, 1917, xxxi. 



216 FOOD INSPECTION AND ANALYSIS. 

Bacon and ham are frequently cured by pickling in brine containing 
salt, saltpetre, and cane sugar, and sometimes also such antiseptics as 
boric acid and calcium bisulphite. 

The curing of bacon is sometimes effected by injecting the pickling 
fluid into the tissues with a " pickle- pump," capable of exerting a pressure 
of 40 lbs. to the square inch, and pro\'ided with a hollow, perforated 
needle-nozzle, which penetrates the flesh. After pickling, the bacon or 
ham may be simply dried, or, if desired, smoked. Oak sawdust is fre- 
quently burned for the smoking of ham. 

The Use of Antiseptics in Meat. — Most of what might be termed 
the modern preservatives are to be looked for in one or another of the 
various meat preparations, though some are better adapted than others 
for use in particular cases, as will be seen by reference to the composition 
of typical commercial preservative mixtures given on page 878. 

Borax and boric acid, usually in mixture, have been used more com- 
monly than any other preservatives for the preservation of meat. Like 
salt, they are used commonly in surface application, in the case of large 
cuts of meat, or by mixing, in the case of sausage meat. A more recent 
method of application consists in impregnating the tissue of the meat 
with a solution of the boric mixture, by means of the above-described 
pickle-pump. The use of boric acid and its compounds, however, is not 
permitted under the regulations of the Federal meat inspection law of 
the United States. 

Sulphurous Acid. — As much as 1% of a solution of sulphurous acid may 
be added to meat without being apparent to the taste or smell. Mitchell 
quotes Fischer as having found that 50% of the preserved meat products 
(sausages, etc.) sold in Breslau in 1895 contained sulphites, varying in 
amount from 0.0 1 to 0.34 per cent of sulphur dioxide. Calcium bisulphite 
is a salt commonly employed. In Hamburg steak it serves partly as a 
preservative, but chiefly as a deodorizer and a restorer of the bright red 
color of fresh meat. 

Sodium Benzoate is not of such common occurrence in meat products 
as the other antiseptics mentioned. 

Salicylic Acid is now seldom used. 

Among other preservative substances sometimes used with meat are 
solutions containing phosphoric acid and aluminum salts. 

The toxic effects of these and other antiseptic chemicals in meats, and 
the most practical means of controlling their use are questions in con- 
tro\'ersy, presenting no new phases that have not been elsewhere dis- 



FLESH FOODS. 217 

cussed in treating of the general question of preservatives in food. 
Methods of detecting preservatives in meats are given elsewhere. 

Drawn vs. Undrawn Poultry.— Much has been written on this subject 
but the consensus of opinion at the present time is in favor of undrawn 
poultry. Boos * found that undrawn birds taken from cold storage 
and exposed to 68° F. showed better keeping qualities than the drawn, 
although freshly killed birds, drawn by a special method not commercially 
practiced, exposed directly to 68° F., showed perfect keeping qualities. 
Pennington f concludes that (i) undrawn poultry decomposes more 
slowly than does poultry which has been either wholly or practically evisce- 
rated, (2) " full drawn " poultry, that is, completely eviscerated, with 
heads and feet removed, decomposes the most rapidly, and (3) " Boston 
drawn " and " wire drawn," the latter being usually the better, are inter- 
mediate. 

Spoilage of Meat. — Bacteriological examination and tests for ptomaines, 
although falling outside the scope of this work, must be carried on in con- 
junction with chemical examination in tracing the process of decomposition. 
Naturally all scientific work is superfluous when the ordinary senses show 
the product to be offensive. Of the chemical methods which have been 
proposed, those for the determination of ammonia in the flesh and free 
acids in the fat are most valuable. 

Bob Veal, that is the flesh of calves butchered soon after birth, has 
long been regarded as unwholesome and its sale has been prohibited by 
Federal and State laws. Reliable methods of deduction are lacking, fur- 
thermore there is evidence by Fish and others that the meat is not, as 
claimed, laxative or otherwise injurious to health. Fetal and still-born 
calves are obviously unfit for food. 

The Effect of Cooking on Meat is a subject of great importance in 
dietetics. Extensive investigations have been carried out by Grindleyl 
and associates showing the losses by different methods of cooking and the 
changes in proteins and other substances brought about. The digestibility 
of the meat was practically the same regardless of kind, method of cooking 
and fatness, the meat in all cases being practically all assimilated. 

The general result of cooking is to render the meat less tough, to develop 
an agreeable flavor, and to coagulate more or less of the proteins. When 

*Mass. State Bd. Health Rep. 1907. 
t U. S. Dept. of Agric, Bur. of Chem., Circ. 70, 191 1. 

tU. S. Dept. of Agric, Ofif. of Exp. Sta., Buls. 102, 141, 162, 193; Bur. of Chem., Bui. 
81, 1904, p. 113. 



218 FOOD INSPECTION AND ANALYSIS. 

subjected to moist heat, such as boihng and steaming, some of the soluble 
materials are dissolved, so that when the liquor in which the meat is boiled 
is thrown away, some of the valuable substances are lost. This is especially- 
true when meat is placed in cold water which is afterwards brought to boil- 
ing, a method to be recommended when the liquor with the dissolved ex- 
tractives is to be used for broth. When the meat to be boiled is placed 
at once in boiling water, there is less loss of soluble matter by reason of the 
formation of a more or less impenetrable coating on the outside, by the 
coagulation of the proteins. Meat that is boiled becomes softer, owing 
to a partial dissolving of the gelatin formed. In the dry cooking of meat, 
as by broiling or roasting, there is usually a hardening of the tissues, and a 
driving out of some of the meat juices, which are, however, often recovered 
in the form of gravies. 

CANNED MEAT. 

The most effective method of preserving meat and meat preparations 
of all kinds for long periods of time consists in sterilizing by heat, and seal- 
ing in air-tight cans. The process of canning cooked meat and its products 
does not differ materially from that employed in the similar preparation 
of vegetables. (See Chapter XXI.) Previous to canning, the meats 
are usually cooked by boiling, during which process the changes described 
in the preceding paragraph take place. 

Adulteration. — The practice of misbranding chopped meat with respect 
to variety has been very prevalent in the past, and many varieties of so- 
called potted and devilled meats and game have frequently consisted wholly 
or in large part of a cheaper variety than that specified on the label. This 
practice has been largely corrected in this country, owing to the enforce- 
ment of the regulations of the Federal meat inspection law. Unfortunately 
the biological tests for foreign meats are not applicable to the cooked products. 

Out of 76 samples examined by McGill,* 8 contained over 2 per cent 
of starch, 5 between i and 2 per cent, 1 7 less than i per cent, while 46 were 
free from starch. 

Preservatives were at one time added to canned meats especially in 
the case of dried arid smoked beef, ham, and bacon, and in potted and 
devilled mixtures, but this practice has been discontinued. 

Composition of Canned Meat. — The following table, compiled from 
results published by Bigelow and others, f shows the composition of 

* Lab. Inl. Rev. Dept., Canada., Bui. 164. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part. 10. 



FLESH FOODS. 



219 



30 « 



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220 



FOOD INSPECTION AND ANALYSIS. 



various common canned and preserved meats and meat products, and in one 
or two instances fresh meat has been included for comparison. 

In obtaining the results from which the table on page 219 was compiled, 
but three divisions of nitrogenous substances were made, viz., (i) those 
insoluble in hot water; (2) those precipitated from the water extract by 
bromine; and (3) the flesh bases. Owing to the incompleteness of the 
bromine precipitate, the figures given there for nitrogen precipitated by 
bromine are somewhat high, and those for nitrogen as meat bases are 
correspondingly low. This fact was observed during the progress of the 
work, and pointed out in the text with the statement that " considering the 
small amount of these bodies contained in meat, the results are believed 
to be approximately correct." 

SAUSAGE. 
Nature and Composition. — Sausages are made from finely chopped 
meat, highly seasoned with various spices, and, as usually sold, stuffed 
into casings made of the cleaned and. prepared intestine-skin of cattle, 
sheep, hogs, or even horses. The meat most commonly used is pork. 
Sausages are frequently home-made, especially in farm communities, 
the chopped and seasoned meat being stuffed in cloth bags instead of 
casings. Any and all kinds of meat are used in sausages, and much that 
is undesirable and even unwholesome is undoubtedly most readily used up 
in this product. There is little doubt that horse meat occasionally gets 
into the hands of the marketmen to be worked up in the form of sausages 
mixed with other meat. The condition in respect to these matters has 
been greatly improved, however, by the increased vigilance of State and 
Federal authorities. Sausages are sometimes artificially colored, and in 
some cases contain so-called " fillers " in the nature of dried bread, corn 
meal, potato starch, crackers, waste biscuit, boiled rice, etc. 

CHEMICAL COMPOSITION OF SAUSAGES.* 





No. of 
Analy- 
ses. 


Ref- 
use. 


Water. 


Protein. 


Fat. 


Total 

Carbo- 
hy- 
drates. 


Ash. 


Fuel 
Value, 
Cals. 


Kind. 


NX6.2S 


By 
Differ- 
ence. 


Farmer: edible portion. . . 

as purchased 

Pork : as purchased 

Bologna: edible portion. . . 

as purchased 

Frankfort : as purchased. . . 


I 

I 

II 

8 

4 
8 


3-9 

3-3 


23-2 
22.2 

39-8 
60.0 

55-2 
57-2 


29.0 

27-9 
13.0 
18.7 
18.2 
19.6 


27.2 
26.2 
12.7 
18.4 
18.0 
19.7 


42.0 
40.4 
44.2 
17.6 
19.7 
18.6 


I.I 
0-3 

I.I 


7-6 

7-3 
2.2 

3-7 
3-8 
3-4 


2310 
2225 
2125 

1095 
I170 
II 70 



• U. S. Dept. of Agric, Off. of Exp. Stations, Bui. 28 (Revised Ed.^. 



••\ FLESH FOODS. 221 

Adulteration of Sausages with Starchy Materials and Water. — 

Robison, who has made a special study of these forms of adulteration at 
the Michigan Dairy and Food Department, states as follows:* "Lean 
meat carefully chopped has an enormous combining power and can be 
made to take up a great quantity of water. Frankfurts, bologna, and 
pork sausage have been found to be adulterated with from 0.5 to 5% of 
starch, indicating an addition of approximately i to 10% of so-called 
cereal (chiefly corn flour), and from 5 to 40% of water in addition to 
that contained in the meats when in their fresh condition. The main 
excuse for the use of water is that it renders the meat of such a consistency 
that it may be easily stuffed into thin cases, such as are usually used for 
sausages that are eaten without removing the casing. As a matter of 
fact, this addition is not necessary where fresh meats are used, nor with 
those cuts of meat which the American public is in the habit of using in 
the manufacture of sausages in the home. Without doubt, in sausages 
composed of ox hearts, ears, snouts, lips, etc., in considerable quantities, 
the addition of water may facilitate the stuffing into thin casings. 

" Starch hastens and increases the absorbing or combining power of 
lean meat. In many instances where inferior products, such as ears, etc., 
are used, virtually it is the only absorbing agent present in the product. 
It then serves a two-fold purpose, first, giving an absorbing power to meat 
which it has not, or inflating the absorbing power of a meat which natur- 
ally is deficient in this respect, and second, acting as a skeleton or frame- 
work, thereby disguising shrinkage during the process of cooking. Gen- 
erally, added water and cereal are evidences of inferiority, and they are 
by no means infrequently added with the very purpose of concealing 
such inferiority. 

" The evidence of adulteration with water is the discrepancy in the 
ratio of the water to the protein in the sausage. This ratio in sausage 
made from the fresh carcass varies from 3:1 to 3.6 : i, being on an 
average about 3.35 : i." 

Baumann and Grossfeld f have also adopted the ratio of water to pro- 
tein but express the latter in the form of nitrogen. Their average ratio is 
18.3 : I whfle Robison's calculated to the same basis is 20.9 : i. The 
data used in calculating their ratio are (i) 3.43 : i, the ratio of water to 
organic fat-free solids as obtained in 640 samples of beef, mutton, pork, 



* Personal communication. 

t Zeits. Unters. Nahr. Genussm., 32, 1916, p. 489. 



222 FOOD INSPECTION AND ANALYSIS. 

and horse sausage, and (2) 5.34, the per cent of nitrogen in the fat-free solids. 
They calculate the per cent of added water (W') from the per cent of total 
water (W) and nitrogen (N) by the following formula: 

W'=^W-{NxiS.^). 

Other authors have advocated the ratio of water to organic fat-free soHds 
as the criterion. Aachen * considers 4:1 a liberal maximum, 3:1 being the 
average, and calculates added water by the formula : 

in which TF' = per cent of added water, IF = total water, and 6*= organic 
fat-free solids. Feder f also believes 4:1a fair maximum ratio while 
Seel I finds it too liberal and advocates 3.5 : i. All of the foreign standards 
and formulas are not strictly applicable to American sausage; the condi- 
tions of manufacture and character of the products are quite different in 
different countries. Obviously, cooking and drying influence materially 
the water content. Sausage made from liver and meats other than muscle, 
blood, etc., belong in special classes. 

Casein is said to be used in Europe as an ingredient of sausage. Al- 
though it performs a mechanical role, it belongs in a different class from 
starch because of the similarity of its nutritive properties to those of lean 
meat. 

Artificial Coloring Matter in Sausages. — Owing to the rapid color 
changes which freshly chopped meat, especially beef and mutton, natu- 
rally undergo, it is a common practice to employ powdered saltpeter 
(p. 215). Treated in this manner, meat remains pink, owing to the action 
on the haemoglobin of the oxides of nitrogen resulting from the nitrate. 
As much as 4 ounces of niter to 100 lbs. of meat is sometimes used. A 
larger quantity would result in a shriveled appearance. Sulphites act 
not merely to prevent decomposition, but also to retain the red color. The 
use of artificial colors has been common in the past, in order to permanently 
dye the flesh a bright red, similar to the tint which the oxy-haemoglobin 
naturally imparts to the beef when fresh. A variety of colors have been 
employed for this purpose, such as red ocher, coal-tar dyes, cochineal, 
etc. They were sometimes used in admixture with preservatives. Their 
use has been limited to certain colors in this country, owing to the enforce- 



* Zeits. Unters. Nahr. Genussm., 25, 1913, p. 577. 
t Chem. Ztg., 38, 1914, p. 709. 
t Ibid., 39, 1915, p. 409- 



FLESH FOODS. 223 

ment of the regulations under Ihe Federal meat inspection laws. Spanish 
red pepper or pimiento is employed more for coloring than for flavoring. 

ANALYSIS OF MEAT. 

In analyzing meats and meat products due regard must be paid to 
theu- perishable nature, and, for this reason, immediately after their 
receipt by the analyst the various determinations should be promptly 
begun and rapidly carried out. If delays are absolutely necessary, the 
samples, as well as some of the solutions, especially during the earlier 
course of the analysis, should be kept on ice to prevent decomposition. 
Even at low temperatures, however, both bacterial and enzymic decom- 
position occur, and the nature of the proteins is slowly changed. Refuse 
material, such as bones, skin, gristle, tendons, etc., are separated as 
completely as possible by means of a knife from the edible portion and 
weighed. The visible fat is farther separated from the lean, both are 
weighed, and the latter, cut first mto small pieces, is passed repeatedly 
through a sausage-machine or ordinary household meat-chopper, in order 
to reduce to a homogeneous, finely divided mass. 

Determination of Water. — Weigh out 2 to 5 grams of the finely 
divided material into a tared platinum or porcelain dish, and dry to 
minimum weight in a boiling-water oven. A slight oxidation of the fat 
may introduce a trifling error, but, excepting for the most exact work, 
where the drying should be accomplished in an atmosphere of hydrogen, 
or at ordinary temperature over sulphuric acid in vacuo, the above method 
is sufficiently close. 

Trowbridge Vacuum Desiccator Method.'^ — Fill a paper extraction 
cartridge, or a glass tube with filter paper bottom, two-thirds full with sand, 
add fat-free cotton, dry at 103° C, keep in a vacuum for a few hours, and 
weigh in a weighing bottle. Remove the sand to a porcelain dish, add 
5 to 10 grams of the sample, mix thoroughly, transfer to the cartridge, wiping 
the dish carefully with the cotton. Place in a vacuum desiccator over sul- 
phuric acid, exhaust to i mm. or less, close stop cock, and allow to stand 
24 to 48 hours, rotating gently every 3 or 4 hours to mix in the watery 
surface-layer of the acid. Transfer to a desiccator containing fresh acid 
and proceed as before, weighing after 24 to 48 hours, which time is usually 
sufficient for constant weight, 

Rohison Method for Sausage. — Dry 100 to 500 grams on a porcelain 
plate at 70 to 90° C. over a radiator for 10 to 15 hours and grind, then carry 

*U. S. Dept. of Agric, Bur. of Chem., Bui. 122, 1909, p. 219. 



224 FOOD INSPECTION AND ANALYSIS. 

out the final drying on a 2 to 5-gram portion at the temperature of boiling 
water employing in exact work a stream of hydrogen. If the sample is 
rich in fat, carry out the drying on a sieve over a vessel to collect the fat 
which is separately weighed and dried for water determination. 

Determination of Fat. — Extraction Method. — Extract 2 grams of the 
sample dri^d at 100° with anhydrous ether for sixteen hours as in the case 
of cereal products (p. 286). More complete extraction is obtained by 
grinding the residue in a mortar and repeating the process and still more 
complete by digestion with pepsin and intermittent treatment with the fat 
solvent, but this latter is both tedious and open to other errors. 

Baur and Barschall^ proceed as follows: Heat i to 1.5 grams of the 
well-ground material in a 250-cc. Erlenmeyer flask under a reflux condenser 
on a water bath with 5 cc. of concentrated sulphuric acid and 5 cc. of water 
until the solution is complete, and then for 10 minutes additional. Dilute 
with 40 cc. of water, cool, add from a pipette 50 cc. of ether, shake vigorously 
for 2 minutes, then add 50 cc. of petroleum ether (b. pt. 50 to 55°), and shake 
vigorously for i minute. Allow to settle for 15 to 20 minutes at 18°, pipette 
off 49.5 cc. of the ethereal solution, which experiments have shown is half 
of the total amount, filter through a cotton plug into a tared flask, wash 
with three portions of 2 cc. each of a mixture of ether and petroleum ether, 
add a minute amount of finely powdered pumice stone (insufficient to 
appreciably affect the weight), and distil off the solvent. Dry in a water 
oven, cool, and weigh as usual. 

Kita Centrifugal Method.-\ — Place 2.5 grams of the well-ground meat 
in a Gerber milk test-bottle (open at one end) with 8 cc. of i :i sulphuric 
acid, or 5 grams in a Gerber cheese test-bottle (open at both ends) with 
1 7 cc. of acid and heat in a water-bath at 60 to 70° with occasional agitation 
for 5 to 10 minutes or till the solution is complete. Add i cc. of amyl 
alcohol and sufficient 1:1 sulphuric acid to bring the layer of fat within 
the neck. Whirl in a centrifuge for 3 to 5 minutes, warm on a water-bath, 
and read the amount of fat on the scale. In som.e cases the centrifuging 
must be repeated. 

Examination of Fat. — Shake a large poition of the original finely 
divided sample in a corked flask with petroleum ether boiling below 60° C., 
and digest for some hours. Pour off the solvent, remove most of the 
petroleum ether by distillation, and the last traces by allowing to stand 



* Arb. Kaisl. Gsndhtsamt., 30, 1909, p. 50; 2>2» iQiOj P- 563. 
t Arch. Hyg., 51, 1904, p. 165. 



FLESH FOODS. 225 

in a vacuum desiccator over freshly ignited calcium chloride. Determine 
the usual constants as described in Chapter XIII. In minced prepara- 
tions these constants furnish a possible clue to the variety of meat used. 

Determination of Acidity of Fat. — Pennington and Hepburn Method. * 
Weigh lo grams of the fat, mechanically separated and ground in a meat 
chopper, directly into a 250 cc. Erlenmeyer flask, add 50 cc. of neutral 
alcohol, and phenolphthalein as indicator, and bring to a brisk boil. 
The hot alcohol dissolves the fat. Titrate immediately with tenth normal 
sodium hydroxide, shaking vigorously, until a pink color appears, which 
persists for one-quarter of a minute. Calculate the acid value from the 
amount of sodium hydroxide used, or the free oleic acid by multiplying 
the acid value by 0.503. 

Determination of Total Nitrogen. — Proceed according to the Gunning 
or Kjeldahl method (Chapter IV) employing 2 to 5 grams of the material. 

If the meat contains nitrates, as is true of corned beef and some other 
salted products cured with the addition of saltpeter, follow the method modi- 
fied to include nitric nitrogen. Richardson does not obtain concordant 
results by the modified method, when a large amount of sodium chloride 
is present, and recommends preliminary boiling with 10 cc. of saturated 
ferrous chloride solution and 5 cc. of concentrated hydrochloric acid to 
remove nitric nitrogen after which the ordinary Kjeldahl or Gunning 
method may be employed. 

Calculate protein using the factor 6.25. Although nitrogenous sub- 
stances other than proteins are present and the factors for the individual 
proteins vary, this factor gives a fairly close approximation to the total 
nitrogenous substance present. 

Determination of Ammoniacal Nitrogen. — Distillation Methods. — Ordi- 
narily the ammonia, liberated by magnesia (freshly calcined magnesium 
oxide), is distilled into standard acid and the excess titrated back with 
standard alkali. This procedure gives results somewhat higher than the 
truth owing to the decomposition of other nitrogenous compounds. 

Richardson and Scherubel-\ proceed as follows: Method I, Distil 100 
grams of the material, 10 grams of magnesia, and 450 cc. of water until 
200 cc. of the distillate have been collected; Method II, Extract 100 grams 
of the material three times with 150 cc. of 60% (by vol.) alcohol and distil 
the combined extracts as in Method I. In both methods employ phenol- 



* Jour. Amer. Chem. Soc, 32, 1910, p. 568. 
t Ibid., 30, 1908, p. 1527. 



226 FOOD INSPECTION AND ANALYSIS. 

phthalein as indicator. If in method I the water driven off is replaced and 
the distillation is repeated, additional ammonia is obtained. After ten 
distillations in this manner the originators of the method obtained a total 
of 0.088% of ammoniacal nitrogen in a sample of fresh meat and 0.095% 
in one of frozen meat, whereas after the first distillation they obtained only 
0.030 and 0.033% respectively. Method 11 gave results about one-third 
as high as by Method I and after the first distillation the increase was 
insignificant. Either method is suitable for comparative purposes as tne 
increase during spoilage is relatively great. 

Folin Aeration Method modified by Pennington and Greenlee.^ — The 
ammonia, set free by sodium carbonate, is evolved at room temperature 
in a rapid current of air. The ingoing air is purified by passing through 
sulphuric acid in a flask provided with a safety bulb. It next passes through 
a liter flask containing 25 grams of the ground meat, i gram sodium car- 
bonate, 250 cc. of water, and 25 cc. of alcohol, then through an empty 
flask to intercept spray into a 250 cc. flask containing tenth normal acid 
and finally through a 100 cc. flask, to catch acid carried over mechanically, 
to an air pump operated by an electric motor and provided with an anemom- 
eter. One pump and one air purifier suffices for four series of flasks, the 
current being divided by means of four- way tubes. A volume of 8000 cu. ft. 
passed through each series in 3 to 6 hours sufiices to remove all the ammonia 
liberated. 

Separation and Determination of Nitrogenous Bodies. — It is rarely 
necessary to go further than to divide the nitrogenous bodies into several 
main groups, according to their solubility in water or other solvents, and 
their behavior toward certain reagents. The nitrogen may be determined 
separately in each of these groups and by the approximate factor the 
corresponding substance or class of substances ascertained. 

A portion of the sample is first exhausted with cold water, which removes 
the soluble proteins (soluble globulins and albumins, proteoses, and 
peptones) and meat bases, leaving behind the insoluble globulins, the 
sarcolemma, the albuminoids of the connective tissue (elastin, etc., also 
insoluble) and the collagen. By next exhausting with boiling water the 
collagen is removed in the form of soluble gelatin. 

The coagulable albumins and globulins are precipitated in the cold 
water extract by boiling and in the filtrate from these, the proteoses by 
addition of zinc sulphate. The remainder of the nitrogen obtained by 

* Jour. Am. Chem. Soc, 32, 1910, p. 561. 



FLESH FOODS. 227 

difference consists in large part of meat bases with a small amount of 
peptones, the accurate separation of which is impossible with our present 
knowledge, although the creatine and creatinine either separately or com- 
bined and the total purine bases may be quite accurately estimated. 

Determination of Nitrogenous Substances Insoluble in Cold Water. — 
It is customary to obtain the insoluble nitrogen by difference after 
determining the nitrogen in an aliquot of the cold water extract. The con- 
version factor for insoluble protein is 6.25. 

Trowbridge and Grindley Method.'^ — Digest looo grams for i hour 
with 1500 cc. of ice water and squeeze through cheese cloth. Divide the 
residue into equal portions in beakers, wash one after the other with the 
same portion of water, filtering each time through cheese cloth, and repeat 
until the last filtrate is colorless, neutral to phenolphthalein, and free from 
protein as shown by the biuret test. 

Emmett Method.-\—W&\^ 7 to 25 grams of the material, according to 
the water content, into a 150-cc. beaker, stir into a homogeneous paste 
with 5 to 10 cc. of ammonia-free water at 15° C, then add a further portion 
of 50 cc. Stir frequently for 15 minutes, allow to stand for 2 to 3 minutes, 
and filter into a 500-cc. graduated flask. Drain off the liquid, using a 
glass rod to press the meat residue. Wash by decantation with three 
portions each of 50 cc. and 25 cc. of water, stirring for 5 minutes each time 
and allowing to settle for 2 to 3 minutes. Transfer the residue to the paper 
and wash three times with 10 cc. of water. Make up to the mark and 
determine nitrogen in a 25-cc. ahquot portion. 

Three aliquot portions of 150 cc. each may be used for the determina- 
tion of (i) coagulable proteins and, in the filtrate, proteoses, (2) coagulable 
proteins and in the filtrate total creatinine (creatine and creatinine) and 
(3) purine bases. If other determinations are desired employ 14 to 50 
grams of material and make up to 1000 cc. 

Emmett rightly observes that by direct treatment with water a solution 
well adapted for the determination of the various forms of soluble nitrogen 
is obtained, thus avoiding any changes which might result from preliminary 
drying and extraction with ether. 

Pennington Method.X — This method was devised for chicken meat. 
Shake gently 60 grams of the finely divided meat in a 500-cc. cylindrical 
bottle with 300 cc. of water for 15 minutes, avoiding sufficient agitation to 

* Jour. Amer. Chem. Soc, 28, 1906, p. 472. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 162, 1913, p. 153. 

X Ibid., Bui. 115, 1908, p. 64. 



228 FOOD INSPECTION AND ANALYSIS. 

form an emulsion. Centrifuge 20 minutes, decant off the supernatant liquid 
onto a paper, add 300 cc. of water to the residue, and proceed as before, 
repeating the treatment until the protein is practically removed as shown 
by the biuret reaction. Usually a volume of 1500 to 2500 cc. is required. 
Employ thymol to prevent bacterial decomposition and a low temperature 
to inhibit the action of natural enzymes. Neutralize the total extract to 
litmus with N/io sodium hydroxide. Determine nitrogen in a loo-cc. 
aliquot portion which is evaporated to 10 cc, before adding the acid. Other 
aliquot portions may be used for determining coagulable and other forms 
of soluble nitrogen. 

Considerable difficulty is experienced in complete removal of soluble 
proteins from the dark meat, especially of cold-storage fowls. The ex- 
traction should not be continued longer than 26 hours. 

Cook shakes 200 grams for 3 hours with 250 cc. of water in a shaking 
machine and washes in linen bags with 2200 to 2500 cc. of water. Weber * 
finds that higher results are obtained by this method using ice water than 
with water at room temperature. 

Determination of Collagen and Gelatin. — The connective tissue of 
fresh meat consists in large part of collagen which on boiling with water is 
slowly converted into gelatin. In canned meat or other cooked meat 
products this conversion has been partly effected. In either case the com- 
mon methods of determination are based on boiling the cold water insoluble 
material with water until the conversion into gelatin is as complete as 
possible. The nitrogen is either determined directly in the filtered extract 
or in the alcohol insoluble portion of the extract as obtained by Stutzer's 
method. The factor for both collagen and gelatin is 5.55. 

Direct Method. — The residue from the cold water extract obtained by 
Emmett's method may be used for the determination. Boil for several 
days with water, filter, make up to a definite volume, and determine nitro- 
gen in an aliquot of about one-fifth the total volume. 

Stutzer Method.^ — This method was originally designed for meat 
extracts but has been used by Bigelow for meats. Evaporate another 
aliquot of one-fifth of the hot-water extract with sand and dry in a water 
oven. Treat with four portions of 100 cc. of absolute alcohol, decanting 
each time on a Buchner funnel connected with a suction flask and provided 
with a layer of long fiber asbestos. Place the beaker in ice water, stir for 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 42. 
t Zeits. anal. Chem., 34, 1895, p. 568. 



FLESH FOODS. 229 

2 minutes with loo cc. of a mixture of loo grams of alcohol, 300 grams of 
powdered ice, and 600 grams of ice water, decant onto the filter adding a 
small piece of ice. Repeat the treatment three times or until the solution 
is colorless keeping the decanted portions in ice water during filtration, 
use two or three Buchner funnels if the filtration is slow and take care that 
the temperature does not rise above +5° C. Finally boil the mixture of 
sand and residue, together with the asbestos, with several portions of 
water, filter, wash with hot water, evaporate the filtrate, and determine 
nitrogen in an aliquot. 

Determination of Myosin.— Konig * states that myosin may be 
obtained in the residue after boiling with water by digestion with 15% 
ammonium chloride solution, filtration and precipitation of the myosin 
in the filtrate by diluting and boiling or by salting out with sodium chloride 
or magnesium sulphate. The myosin separated by filtration is dissolved 
in a definite volume of concentrated sulphuric acid and an aliquot used for 
nitrogen determination. He considers that the nitrogenous matter remain- 
ing undissolved after successive treatment with cold water, boiling water, 
and 15% ammonium chloride solution is sarcolemma or insoluble muscle 
fiber. 

The methods for collagen and myosin are not entirely satisfactory 
especially in view of our imperfect knowledge of the albuminoids and 
globulins, present in meat.f 

Determination of Coagulable Protein (A\h\mnn).—Gnndley and 
Emmett AfeZ/zo J. |— Evaporate 150 cc. of the cold water extract obtained as 
directed by Emmett to 40 cc. If necessary add carefully very dilute acetic 
acid or sodium hydroxide solution until faintly acid to litmus paper and 
boil. Collect the coagulum on a filter, wash with hot water, and determine 
nitrogen, correcting for any nitrogen that may be present in the paper. 
Nx6.25 = coagulable protein or albumin. 

Trowbridge and Grindley § obtain the maximum results in fresh beef 
by neutralizing one-fourth of the acidity to phenolphthalein before coagu- 
lation. 

Some analysts filter before neutralization and determine separately 

* Chemie der Menschlichen Nahrungs- und Genussmittel, 4 Auf. Ill Bd. 2 Th., 1914, 
p. 24. 

t See V. Furth, Arch. Path. Pharm., 37, 1896, p. 389; Ergebnisse der Physiologic Ab. i, 
I, 1902, p. 110; Ibid., Ab. 2, I, 1903, p. 575. 

t Jour. Amer. Chem. Soc, 27, 1905, p. 665; U. S. Dept. of Agric, Bur. of Chem., Bui. 
1.62, p. 146. 

§ Jour. Am. Chem. Soc, 28, 1906, p. 494. 



230 FOOD INSPECTION AND ANALYSIS. 

any precipitate that forms on boiling after neutralizing. The second 
precipitate is known as syntonin or acid albumin. 

The filtrate from one duplicate may be used for determining proteoses, 
the filtrate from the other for determining total creatinine. 

Determination of Proteoses, Peptones, Creatine, Creatinine, Purine 
Bases, and Total Meat Bases. — Follow the methods as described under 
meat extracts (pp. 253 to 258). 

No accurate method is available for the determination of total meat 
bases. The practice of obtaining them from the remainder after sub- 
tracting the sum of the coagulable and proteose nitrogen from the total 
water soluble nitrogen, or after subtracting the proteose nitrogen from the 
total nitrogen in the filtrate from the coagulable nitrogen as followed ty 
Richardson, does not correct for the peptones or related substances thus 
determined with the bases. Bigelow and Cook's procedure of calculating 
the nitrogen in the filtrate from the tannin-salt precipitate, correcting for 
nitrogen in the reagent and ammonia in the sample, and multiplying by 
3.12 to obtain the meat bases is subject to error in that part of the creatine 
is precipitated by the tannin-salt reagent and that the factor is accurate 
for only one base, creatine; furthermore, according to Richardson, the 
method is difficult to handle and obtain concordant results due (in part 
at least) to nitrogen in the reagent. The estimation of the " peptones " 
by substracting the sum of the coagulable, proteose, and meat base nitrogen 
by the tannin-salt method from the total soluble nitrogen and multiplying 
by 6.25 is likewise unsatisfactory although probably the best procedure 
now available. 

Determination of Ash. — Incinerate the residue from the total solids in 
the original dish at a low red heat. It is usually advantageous, especially 
in the case of salt meat, to exhaust the charred sample with water, collect 
the insoluble residue on a filter and ignite. The filtrate is then added, 
evaporated to dryness, and the whole heated to low redness and weighed. 
A perfectly white ash is difficult to obtain. 

Determination of Mineral Constituents. — Determine in the original meat 
total sulphur and in the ash chlorine, potassium, sodium, phosphoric acid, 
and other mineral constituents, following the usual methods of analysis. 
The scheme for ash analysis given on page 310 is applicable to meat 
ash. 

Determination of Acidity. — The acidity of meat is due largely to 
(f-lactic acid with small amounts of succinic, acetic, and other acids. The 
results by direct titration are usually calculated in terms of lactic acid. 



FLESH FOODS. 231 

Mondschein found that about one- third of the acid is held back in the 
coaguium and proposes the following method: 

Mondschein Method.* — Suspend 50 grams of the finely ground sample 
in 60 to 80 cc. of water; coagulate by boiling, filter by suction, and wash 
with boiling water three times or until the reaction is no longer acid. 
Titrate the filtrate with N/io alkali using phenolphthalein as indicator. 
Calculate as free lactic acid. 

Remove the matted coaguium from the filter, stir up in a beaker with 
50 cc. of water, add 10 cc. of 10% sodium hydroxide solution, and boil, 
taking care that the liquid does not froth over, thus liquefying the mass 
except for a few particles. Add 100 cc. of saturated sodium chloride 
solution, heat to boiling, and saturate at boiling heat with solid sodium 
chloride. Filter the precipitate thus formed with the aid of suction, wash 
with a hot saturated sodium chloride solution, and add to the filtrate sul- 
phuric ftcid to faint acid reaction, thus precipitating proteins. Boil, add 
5 cc. of sulphuric acid, make up to 500 cc, and filter through a dry paper. 
Heat 250 cc. of the filtrate to boiling and add N/10 potassium permanganate 
solution until the lactic acid is split up into acetaldehyde, carbon dioxide, 
and water.f Add an equal bulk of potassium bisulphite solution (12 grams 
per liter), the strength of which has been determined against N/io iodine 
solution, mix, and after 15 minutes titrate with N/io iodine solution i cc. 
of which equals 0.005 gram lactic acid.| 

Mondschein also describes a more complicated method for use in 
separating J-lactic from /3-hydroxybutyric acid, which however does not 
appear to have practical application in meat analysis. 

Determination of Starch.— In the following methods it is assumed that 
glycogen is not present in sufificient amount to appreciably afTect the 
results. If microscopic examination shows the presence of starch and 
horse meat or liver is suspected, follow the Mayrhofer-Polenske method 
(P- 234). 

Mayrhofer Method.— The first paragraph of the description of the Mayr- 
hofer-Polenske method is essentially the Mayrhofer method as originally 
devised for starch. 

Mayrhofer- Price Method.^ — Heat on a boiling water bath 10 grams 
of finely-divided meat with 75 cc. of 8% potassium hydroxide in 95% alcohol 

* Biochem. Zeits., 42, 1912, pp. 91, 105. 

fv. Fiirth and Charnass, Biochem. Zeits, 26, 1910, p. 199. 

t Ripper, Monatsh. Chem., 21, 1900, p. 1079. 

§ U. S. Dept. of Agric. Bur. of Anim. Ind. Circ, 203, 1912. 



232 



FOOD INSPECTION AND ANALYSIS. 



until all the meat is dissolved (30 to 40 min.). Add an equal volume of 
95% alcohol, cool, and after i hour decant carefully on a Gooch crucible 
with a thin layer of asbestos. Wash carefully by decantation twice with 
4% potassium hydroxide in 50% alcohol and twice with warm 50% alcohol. 
Add to the residue and crucible with contents 40 cc. of water and then 
with constant stirring 25 cc. of concentrated sulphuric acid. After 5 
minutes add 40 cc. of water and heat just to boiling with constant stirring. 
Transfer to a 500-cc. graduated l^ask, add 2 cc. of 20% phosphotungstic 
acid solution, cool, make up to the mark, mix, and filter through starch- 
free filter paper. Neutralize an aliquot portion of the filtrate and deter- 
mine dextrose by one of the methods described in Chapter XIV. Price 
recommends Low's method.* 

Identification of Horse Flesh. — Although certain authorities have 
found distinguishing characteristics in color, consistency, odor, etc., between 
horse flesh on the one hand, and beef and pork on the other, it is extremely 
difficult, by its physical properties, to detect horse flesh when mixed with 
other meat, especially when the mixture is chopped. Horse flesh has a 
much coarser texture and is darker in color than beef. The muscle fibers 
are, as a rule, shorter in horse flesh. On treating horse flesh with formal- 
dehyde, Ehrlich f has found that a very characteristic odor is developed 
within forty-eight hours, suggestive of roasted goose flesh. 

Certain of the constants of the fat of horse meat differ from those of 
beef and pork, notably the iodine value and the refractometer readings. 
These constants are compared as follows: 





Iodine Value. 


Butyro- refractom- 
eter Readings. 
Temperature 40°. 


Horse fat 


71-86 
38-46 
50-70 


S3 7 
49.0 
48.6-51.2 


Beef fat 


Hog fat 



The fact that glycogen usually exists to a much larger extent in horse- 
flesh than in other meat, and that a considerable amount remains after that 
of other meat has disappeared, renders it possible in some cases to detect 
horse flesh, when present in the mixture. 

The following table prepared by Bujard shows the relative amount of 
glycogen in various kinds of meat and sausages: . 

* Jour. Amer. Chem. Soc, 24, 1902, p. 1082. 
fZeits. Fleisch Milchhyg., 1895, p. 232. 



FLESH FOODS. 



233 



Water. 



Glycogen Direct. 



Niebel 
Method. 



Mayrhofer 
Method. 



Glycogen in Dried 

Substance. 



Niebel. 



Mayrhofer. 



Horse flesh 

Red sausage (Knackwurst) 

Pork sausage 

Veal 

Pork 



0.440 
0.600 
1-827 
0.592 



0.445 

0.520 

1.727 

0.610 

0.038 

0.24 

0.086 

0.186 



1. 721 
2.388 
7.667 
2.466 



1. 741 
2.069 
7.247 
2-542 
0.124 

0.733 
0.342 
0.744 



In beef Bujard found 0.073 ^^^ o-74 P^r cent of glycogen calculated in 
terms of dried substance, and, in sausages made exclusively from horse 
meat, amounts of glycogen ranging from 0.05 to 5.34, the sample in the 
latter case being made from the liver. It was formerly thought possible 
to detect as small an amount as 5% of horse flesh in mixture, but later 
investigation showed that after the death of the animal, glycogen, though 
present at first in considerable quantity, decomposes more or less rapidly, 
going over into muscle sugar (dextrose). Hence, while the presence of 
much glycogen is suspicious, its absence is by no means proof that horse 
flesh was not used. 

Niebel did not consider the failure of the glycogen test as sufficiently 
conclusive to establish the absence of horse flesh, on account of the tendency 
toward decomposition of the glycogen. In the absence of starch, he 
regards the presence of more than 1% of dextrose in the fat-free meat, 
after conversion of the carbohydrates, to be proof of the presence of horse- 
flesh. 

Detection of Glycogen. — From the well-known reaction produced 
by iodine on glycogen, horse flesh can often be detected, when present in 
sausages, unless obscured by the presence of starch or dextrin. 

Brautigam and Edelmann * proceed as follows : 50 grams of the finely 
divided meat are boiled with 200 cc. of water for an hour, and, after cool- 
ing, dilute nitric acid is added to the broth to precipitate the proteins 
and to decolorize. The broth is then filtered, and a portion of the filtrate 
is treated in a test-tube with a freshly prepared, saturated, aqueous solution 
of iodine, or, better, with a mixture of 2 parts iodine to 4 parts potassium 
iodide and 100 parts water, the reagent being carefully added so as not 



* Pharm. Central., 1898, p. 557. 



234 FOOD INSPECTION AND ANALYSIS. 

to mix with the broth, but form a layer above it. If glycogen be present 
in considerable amount, a wine-colored ring is observable at the junction 
of the two layers. On heating the test-tube, the coloration disappears 
if due to glycogen, but it reappears on cooling. This reaction was found 
to occur with horse flesh and not with beef, mutton, veal, or pork.* 

If the color is not clearly apparent, the chopped meat is heated on the 
water-bath with a solution of potassium hydroxide (using an amount of 
potassium hydroxide equivalent to 3% of the weight of the flesh) till the 
fiber is decomposed, after which the broth is concentrated to half its volume, 
treated with nitric acid to precipitate the proteins, filtered, and treated 
with the iodine solution as previously. 

Determination of Glycogen in the Absence of Starch. — Pfiilger Method.-\ 
— Heat on a boiling-water bath 100 grams of the material with 100 cc. of 
60% potassium hydroxide for 3 hours, cool, transfer to a large beaker, 
dilute to 400 cc, precipitate with 8co cc. of 95% alcohol, and allow to 
settle over night. Decant off the liquid as completely as possible onto a 
filter, fill up the beaker with 66% alcohol containing i cc. of saturated 
sodium chloride per liter, and stir vigorously for a long time. After the 
glycogen settles decant off the liquid, repeat twice the washing with the 66% 
alcohol, and then wash twice with 95% alcohol, once with absolute alcohol, 
three times with absolute ether, and three times with absolute alcohol. 
Dissolve the glycogen in a small amount of hot water, make slightly acid 
with acetic acid, filter, and fill up to a definite volume. Determine the 
sugar in the solution either by direct polarization, specific rotation of 
glycogen + 196.5 7°, or by conversion into glucose and copper reduction. 

In the latter case invert 100 cc. by heating for 3 hours on a water-bath 
with 5 cc. of hydrochloric acid (sp.gr. 1.19) and proceed according to the 
AUihn method. Dextrose Xo.927 = glycogen. 

Separation and Determination of Glycogen and Starch. — Mayrhofer- 
Polenske Method. % — Dissolve 50 grams of the ground meat, containing as 
little fat as possible, in a 450 -cc. beaker with 150 cc. of a solution of 80 grams 
of potassium hydroxide in i liter of 90% (by vol.)' alcohol, by warming on a 
water-bath with occasional stirring which requires about h hour. - Add 
100 cc. of 50% alcohol to the hot liquid, cool, and filter by suction in 
Witt's or some other suitable filtering device. Wash the residue with 

* The reaction was found to occur also with the flesh of the human foetus and with the 
foetus of animals; also with mule meat, but not with the flesh of the dog or cat. 
t Pfliiger's Arch. Ges. Physiol., 1C3, 1903, p. 169; 114, 1906, p. 231. 
t Arb. Kaisl. Gsndhtsamt., 24, 1906, p. 576. 



FLESH FOODS. 235 

30 cc. of alcoholic potash at 50°, then with 90% cold alcohol until the filtrate 
no longer becomes turbid with a few drops of dilute hydrochloric acid. 
Transfer the insoluble residue to a iio-cc. graduated flask, add 50 cc. of 
normal aqueous potassium hydroxide and heat J hour on a water bath to 
dissolve the glycogen and starch. On cooling acidify the solution with 
concentrated acetic acid, make up to the mark, and filter. To 100 cc. 
of the filtrate add 150 cc. of absolute alcohol and after the glycogen and 
starch have settled (12 hours) collect on a tared Gooch crucible or filter 
paper. Wash with 70% alcohol until the filtrate contains no more solid 
matter and finally with a little absolute alcohol and ether. Dry first at 
40°, then at 100° to constant weight, determine ash in a portion and deduct. 
Multiply by 2.2 to obtain the percentage of glycogen and starch in the meat. 

The method up to this point is in all essential details the original Mayr- 
hofer * method for determination of starch, the amount of glycogen present 
in aged meat products, such as sausage containing no horse flesh, being too 
small to appreciably viciate the results in determining a considerable addi- 
tion of starch. Only when starch has been found by microscopic examina- 
tion or the iodine test and the presence of meat with high glycogen content, 
such as horse flesh or liver, is suspected, is it necessary to attempt a sepa- 
ration by the following procedure: 

Weigh out 0.3 to 0.5 gram of the precipitate, dissolve in 30 to 40 cc. 
of water, and add double the volume of saturated ammonium sulphate 
solution. Allow to stand 2 hour and separate the precipitated starch from 
the solution of glycogen by filtration. Before washing the precipitate, test 
the filtrate with a dilute solution of iodine in potassium iodide and if a 
blue color appears, add saturated ammonium sulphate solution to the 
filtrate and after the precipitate which forms on standing has settled, 
filter on the paper containing the former precipitate. If, however, the color 
obtained with the iodine solution is red-violet by reflected and Bordeaux- 
red by transmitted light, the second precipitation is unnecessary. Wash 
the precipitate on the paper three times with half-saturated ammonium 
sulphate solution, then dissolve with normal sodium hydroxide into a 
beaker, wash first with normal sodium hydroxide, and finally with water. 
Neutralize the opalescent filtrate with acetic acid and precipitate with 
alcohol as above described. Collect on a tared Gooch crucible or filter 
paper, wash first with 50% alcohol and finally with absolute alcohol, 
dry at 100°, and weigh. 

* Forsch. Ber. Lebensm., 3, 1896, pp. 141, 429. 



236 FOOD INSPECTION AND ANALYSIS. 

The glycogen may be obtained by difference, subtracting the weight 
of starch from that of starch and glycogen previously found, or directly as 
follows: Dilute the filtrate from the precipitated starch with three to foui 
volumes of water, add an equal volume of alcohol, allow to settle 12 hours, 
filter, wash with 50% alcohol, and dissolve in a small quantity of water. 
Reprecipitate the glycogen in the strongly opalescent solution with alcohol, 
collect on a tared Gooch crucible or filter paper, wash with alcohol, dry 
at 100°, and weigh. 

Identification of Raw Horse Flesh by Biological Tests. — Precipitin 
Test. — This test depends upon the principle developed by Uhlenhuth and 
others,* that when a rabbit has been inoculated with the blood of a particu- 
lar animal, as for instance that of the horse, the serum of the rabbit's blood 
will react with the blood of the horse and with that of no other animal. 
Only raw flesh responds to the test, as heating destroys the reacting sub- 
stance. 

To prepare the serum (antiserum) reagent, inject into a rabbit, either 
subcutaneously or intravenously, 5 cc. of defibrinated horse blood and repeat 
the treatment several times allowing intervals of 2 to 5 days between the 
treatments and increasing the dose up to 10 cc. or more until the serum of 
the blood drawn from the rabbit shows the proper activity. When of high 
potency it should react with horse blood serum diluted with 2o,cco parts 
of 0.85% (physiological) salt solution but ordinarily a lower potency is 
sufficient. To obtain the serum from the blood, allow a few cubic centi- 
meters to coagulate spontaneously. If the blood is replaced by 0.85% 
salt solution the life of the animal may be preserved. 

Prepare an extract of 50 grams of the finely ground sample, previously 
shajcen with chloroform or ether if much fat is present, by soaking for 3 
hours at room temperature or over night in an ice box with 100 cc. of 0.85% 
salt solution. Test the filtered extract to determine if it is of the proper 
dilution (i part albumin per 300 cc.) by heating i cc. with i drop of nitric 
acid. If a decided turbidity forms in 5 minutes and settles as a precipi- 
tate it is of suitable strength. Neutralize with 0.1% sodium hydroxide 
solution if acid. To i cc. of the extract add carefully without mixing 
0.1 cc. of the antiserum. Treat in like manner for comparison i cc. 

* Uhlenhuth, Deutsch. Med. Wochs., 1901, p. 780; Wassermann and Schiitze, Ibid., 
igo2, p. 483; Schiitze, Ibid., 1902, p. 804; Miessner and Herbst, Arch. wis. prakt. Tierheilk., 
1902, p. 359; Wassermann, Zeits. Hyg., 2, 1903, p. 267; Uhlenhuth, Weidanzand Wedemann, 
Arb. Kaisl. Gsndhtsamt., 1908, p. 449; Gaujoux, Hyg. viande lait, 4, p. 65, 132; Uhlen- 
huth and Weidanz, Schweiz. Wochs., 48, p. 724. 



FLESH FOODS. 237 



portions of extracts prepared from horse and other meat. If a cloudiness 
and finally a decided precipitate forms within 30 minutes the presence of 
horse meat is indicated. 

For further particulars the reader is referred to the papers given in the 

it nnfpc 



foot notes. 



The preparation of the antiserum, if not the conducting of the actual 
test, falls properly within the province of the biologist or serologist who 
has at his command suitable experimental animals and is experienced in 
judgmg the tolerance of the rabbit for the injections as well as in carrying 
out other details of serum work. 

The Compliment Fixation Test is said to be even more delicate than the 
foregomg. Details of the process are given by Seiffert.* 

Determination of Sugars.-The small amount of dextrose naturally 
present m meat and the sucrose added to ham and other salted meats 
m cunng are best determined by copper reduction. After removal of 
mterfermg substance by suitable reagents, W. B. Smith f precipitates with 
picric acid and phosphotungstic acid thus removing proteins, which have 
a solvent action on cuprous oxide, and creatinine, which reduces FehlinR 
solution. ^ 

Smith Method.-BoW 50 grams of the finely-ground sample, as free as 
possible from fat, with 15c cc of water for 15 to 20 minutes., cool, add i to 
5 grams of solid picric acid and 15 to 20 cc. of 20% phosphotungstic acid 
solution, and make up to 250 cc. exclusive of the fat. Filter through a dry 
paper and make up 150 cc. of the filtrate to 160 cc. with 8 cc. of concen- 
trated hydrochloric acid and 2 cc. of water. Mix, filter through a dry 
paper and without delay determine reducing sugars (as dextrose) in an ali- 
quot, after neutralizing, by one of the usual methods. To another por 
tion of the filtrate add concentrated hydrochloric acid sufficient to bring 
the total amount present up to one-eleventh of the total volume Neutral 
ize and determine the dextrose by copper reduction. Deduct the amount 
obtained by direct inversion and calculate as sucrose. 

^ HoaglandX precipitates creatinine and other nitrogenous constituents 
with phosphotungstic acid alone and removes the excess with potassium 
chloride thus avoiding the possible inversion of sucrose by free hydro- 
chloric acid and the necessity of neutralizing. 

* Zeits. Hyg. Infektionskr., 71, 1912, p. 547; Konig, Chemie der Menschlichen Nahrune*- 
und Genussmittel, 3, i Th., 1914, p. 340; 2 Th., p. 44. ^aUrung*- 

t Jour. Ind. Eng. Chem., 8, 1916, p. 1024. 
t Jour. Biol. Chem., 31, 1917, p. 67. 



238 FOOD INSPECTION AND ANALYSIS. 

Detection and Determination of Sulphurous Acid. — Proceed as directed 
in Chapter XVIII. 

Traces should be ignored, as slight reactions for sulphurous acid are 
obtained with meats that have not been chemically preserved. 

Winton and Bailey * found that in 50 grams of fresh beef, mutton, 
veal, and pork not more than o.i mg. of sulphur dioxide and no hydrogen 
sulphide was present, whereas on decomposition as high as 2.1 mgs. of 
sulphur dioxide and 3.4 mgs. of hydrogen sulphide were developed. From 
these figures it is evident that the examination for sulphur dioxide should 
be made only on the fresh meat. 

Folck and Farreras f use iodate-starch paper for detecting sodium 
hydrogen sulphite in meat. They prepare the test paper by mixing a care- 
fully prepared starch paste (2.5 grams of starch to 95 cc. of water), after 
cooling, with a solution of i gram of sodium iodate and 2.4 grams of citric 
acid in 5 cc. of water, saturating filter paper with the mixture, and drying 
in the dark protected from fumes. In applying the test macerate 5 to 15 
grams of the meat for 5 minutes with sufificient water to cover, strain, 
and test the liquid with the iodate-starch paper which becomes blue in the 
presence of the sulphite. The method compares favorably with the 
Rosell method depending on the decolorization of 1% potassium perman- 
ganate solution by the water extract of the meat. 

Detection of Boric Acid. — Boil 25 grams of the ground material with 
50 cc. of water, cool, and filter on a wet paper to remove fat and meat 
fibers. Test the acidulated aqueous extract with turmeric paper as directed 
under milk. 

A more delicate method of procedure consists in burning to an ash 
a portion of the meat, after treatment with lime water, and testing with 
turmeric tincture a solution of the ash slightly acidified with hydrochloric 
acid. 

Determination of Boric Acid. — See Chapter XVIII. 

Detection of Benzoic Acid. — Proceed with a portion of the aqueous 
solution, prepared as above, according to the instructions given in Chapter 
XVIII or prepare a special solution as follows: 

La Wall and Bradshaw Method modified by Fischer and Gr^ienert.X — 
Agitate 50 grams of the finely ground sample for 30 minutes with ico cc. of 
50% alcohol acidified with sulphuric acid. Strain through cloth, add 

* Jour. Amer. Chem. Soc, 29, 1907, p. 1499. 

t Boll. chim. farm., 53 1914, p. 106. 

X Zeits. Unters. Nahr. Genussm., 17, 1909, p. 721. 



FLESH FOODS. 239 

sodium hydroxide solution to alkaline reaction, and evaporate on the 
water-bath until all the alcohol is removed. Make up to 50 cc, add 
5 grams of sodium chloride, acidify with sulphuric acid, heat to boiling, 
cool, and filter. Shake the filtrate with ether in a separatory funnel, 
wash the ethereal solution with a little water, and evaporate to dryness at a 
gentle heat. Test the residue as described in Chapter XVIII for both 
benzoic and salicylic acids. 

Determination of Benzoic Acid. — Prepare the solution as described in 
the foregoing method, except that the meat is extracted with several portions 
of 50% alcohol, dealcoholize in an alkaline solution and proceed accord- 
ing to the La Wall and Bradshaw method, page 893. 

Kriiger Method.'^ — Place 50 grams of the ground sample, containing 
70 to 75*^0 of water, in a Kjeldahl flask with 45 cc. of 70^0 sulphuric acid. 
If less than 70^0 or more than 75% of water is present in the sample use 
less or more of the material and adjust the strength and amount of acid 
accordingly. Connect with a steam-distillation apparatus and heat cau- 
tiously with shaking, using an asbestos pad with a round hole cut in the 
middle to confine the heat to the portion of the flask in contact with 
the liquid. When the solution becomes clear distil in a current of steam 
regulating the heating of the flask so that the volume remains constant and 
a distillate of 500 cc. is obtained in about 75 minutes. 

Filter the distillate, which must be cool as it flows from the condenser, 
wash with a little cold water, add sodium hydroxide solution to faint alkaline 
reaction, evaporate to small volume and transfer to a porcelain dish of ico-cc, 
capacity. Heat on a boiling water-bath and add in small portions with 
stirring sufficient cold saturated potassium permanganate solution to form a 
red color that persists for five minutes. Destroy the excess of permangan- 
ate with cold saturated sodium sulphite solution and evaporate to about 
10 cc. Transfer to a separatory funnel, acidify with i : 3 sulphuric acid, 
dissolve the precipitate remaining in the dish with small portions of the 
sodium sulphite solution and dilute acid using the mixture to rinse the dish. 
Extract the solution, which should not exceed 20 cc. in bulk three times, 
with an ec^ual volume of a mixture of ether and petroleum ether. Wash the 
combined extract three times with 3 cc. portions of water, and remove the 
last traces of water by shaking with the quantity of powdered gum traga- 
canth that is held on the end of a small knife blade. Transfer to a weighed 
glass dish, using a mixture of ether and petroleum-ether for rinsing, allow 

* Zeits. Unters. Niahr. Genussm., 26, 1913, p. 12. 



240 FOOD INSPECTION AND ANALYSIS. 

to evaporate at room temperature, dry 2 hours over soda lime and weigh. 
As a check dissolve in neutral alcohol and titrate with N/io sodium hydrox- 
ide using phenolphthalein as indicator. If the weight of benzoic acid is 
less than 30 mg. the results may be high in which case the benzoic acid is 
removed by sublimation and the dish reweighed. 

Detection of Salicylic Acid. — Test a portion of the ether extract, ob- 
tained as described for benzoic acid, with ferric chloride solution. A deep- 
violet coloration indicates salicylic acid. 

Detection of Starch in Sausages, Meat-balls, etc. — The addition of 
cracker or bread crumbs is best indicated by the presence of considerable 
starch, which is readily recognized by the iodine test, applied by boiling 
up a portion of the sample with water, cooling and adding a drop of 
iodine reagent to the liquid. The characteristic blue color is produced, 
if starch be present in notable quantity. Traces of starch may be due 
to the pepper and spices used in seasoning the sausage. A small admix- 
ture of starch is rendered apparent if a small portion of the sausage is 
treated with a drop of iodine reagent and viewed under the microscope. 
A microscopical examination will sometimes reveal the character of the 
starch, whether it is from cereals or from pepper, but in some preparations 
the starch is thoroughly cooked and its structure destroyed. 

Detection of Coloring Matter. — Red Ocher is indicated by an excessive 
amount of iron in the ash. 

Cochineal is most readily tested for by the method of Klinger and 
Bujard.* The sausage, finely divided, is heated with two volumes of a 
mixture of equal parts of glycerin and water for several hours on the 
water-bath, the mixture being slightly acidified. The yellow solution 
is passed through a wet filter, and the coloring matter, if present, is pre- 
cipitated as a lake by adding alum and ammonia, the precipitate is filtered 
off and washed, after which it is dissolved in a small amount of tartaric 
acid, and the concentrated solution; contained in a test-tube, is examined 
through the spectroscope for the characteristic absorption-bands of carmine 
lake, lying between b and D. 

Spaeth t has shown that both carmine (cochineal) and anilin red, 
which are the dyes most commonly used for coloring sausages, can be 
most readily extracted therefrom by warming the finely divided material 
a short time on the water-bath with a 5% solution of sodium sali- 
cylate. 

* Zeits. angew. Chem., 1891, p. 515. 
t Pharm. Central., 38, 1897, p. 884. 



FLESH FOODS. 241 

Vegetable and Coal-tar Colors. — In addition to the solvents named above 
various others, such as methylated spirits (Allen), acidified alcohol (A. 
S. Mitchell), amyl alcohol, ether, ammonia, and those used in the exam- 
ination of fats and oils (Chapter XIII), are useful in special cases. The 
solvent, after filtering, is evaporated to small volume, acidified with hydro- 
chloric acid, and white wool is boiled in it. If the wool is distinctly dyed, 
a coal-tar color is undoubtedly present, and this can often be identified 
by methods given in Chapter XVII. According to Marpmann, pure 
normal flesh containing natural color only is completely decolorized by 
macerating for two hours in 50% alcohol, while artificially colored meat 
remains colored after this treatment. Richardson * warns against mis- 
taking for an artificial color the bright red substance often extracted by 
ether or alcohol and ether from meats cured with saltpeter. 

Marpmanri's Microscopical M elhods .'\—Mo\ziexi a thin section of the 
sausage with 50% alcohol, and examine under the microscope. Some 
colors are readily apparent without further treatment. If only traces 
of color are present, clarify the substance by treatment with xylol, which 
is removed by the use of carbon tetrachloride. The mass rendered trans- 
parent by this treatment is then immersed in cedar oil and examined, 
the coloring matters, if present, being especially apparent. If the color 
used is fuchsin (magenta), carmine, logwood, or orchil, the substance 
of the cell will appear stained. If acid coal-tar dyes are used, the liquid 
contents of the cell will show the color. 

Detection of Frozen Meat.— Maljean J detects frozen meat by the 
aid of a microscope. A drop of the blood or meat juice is pressed out 
upon a slide and immediately examined before it solidifies. Fresh meat 
juice contains many red blood corpuscles, floating in a clear colorless 
serum, and readily apparent. In blood from frozen meat, the red cor- 
puscles are nearly always completely dissolved in the serum, due to freez- 
ing, or, if not dissolved, are much distorted and entirely decolorized, the 
liquid portion being darker than usual. 

Megascopically, the fresh meat juice is more abundant than that of 
frozen meat, and its color is deeper. According to C. A. Mitchell, if a 
small piece of meat once frozen be shaken in a test-tube with water, color 
is imparted to the water much more quickly than with fresh meat, and 
the color is deeper. 

* Allen's Commercial Organic Analysis, Phila., 1914, 8, p. 364. 
t Zeits. angew. Mikros, 1895, p. 2. 
X Jour, pharm. chim., 25, 1892, p. 348. 



242 FOOD INSPECTION AND ANALYSIS. 



MEAT EXTRACTS AND SIMILAR PRODUCTS. 

Meat Extracts. — Methods of Manufacture. — Numerous preparations 
sold under the name of meat extracts have been on the market for many 
years. At the beginning of the nineteenth century the value of such 
extracts was knov^^n, but Liebig was the first some fifty years later to pro- 
duce a commercial extract of meat. Liebig's preparation, as originally 
made, consisted of a cold-water extract of chopped lean meat, strained 
free from fiber, heated, filtered, and evaporated, thus containing little if 
any gelatin or proteins. Later, however, Liebig advocated the use of 
warm and even boiling water for extraction, by which method of prep- 
aration a greater amount of gelatin is brought into solution. He, how- 
ever, condemned the use of salt. 

The best modern meat extracts are prepared from meat freed from 
bone and superfluous fat by treatment with hot or boiling water, the time 
and temperature of extraction varying greatly with the different processes. 
While in Argentina, in former times when cattle were plentiful, meat 
extract was the main product and the extracted residue was considered 
of little value, at the present time, at least in the United States, the extract 
is commonly a by-product obtained by evaporating the liquor in which 
meat has been cooked for canning. The concentration of the liquor is 
carried on in vacuum kettles to a water content of about 50% for liquid 
extracts or 18 to 25% for solid or pasty extracts. As corned beef is the 
most popular canned meat, the liquor in which it is cooked is the chief 
source of supply. It contains a considerable amount of salt as well as a 
little saltpeter and sugar, the salt according to Richardson * being removed 
in sufficient amount by concentrating and centrifuging to comply with 
the standards as given on page 252. While in certain cases salt is a 
willful addition, under conditions now existing in the United States, it 
is more apt to be an impurity which the manufacturer is concerned in 
removing. 

Meat extracts are commonly packed in glass or earthern-ware jars. 
The use of tin containers has been found objectionable because of the 
blackening of the cans due, according to Beveridge,t to tin sulphide, 
iron sulphide, and iron oleate. 



* Allen's Commercial Organic Analysis, Phila., 1914, 8, p. 396. 

t Third Rep. Com. Physiol. Effects of Fsod, Training and Clothing on the Soldier, 
London, 1908, 73. 



FLESH FOODS. 243 

Constituents. — The chief constituents are coagulable proteins belonging 
to the globulin and albumin groups, proteoses (albumoses), meat bases, 
phosphates, and chlorides. Small amounts of lactic acid, inosite, and 
other minor constituents of meat soluble in hot water are also present. 
True peptones are usually either not present or else the test is obscured 
by interfering substances. According to Micko * although gelatin in 
small amounts is present in the liquor from which meat extract is pre- 
pared, the finished product does not contain gelatin as such, but rather 
in the form of acid glutin or gelatose which respond to the biuret test 
like gelatin, but do not form a jelly. This change is due to the action 
of lactic acid during concentration. Adam f reports formic acid in all 
the samples of extracts and related products examined. He states it is 
formed by the action of nitric acid on starch used in the process of 
manufacture. 

By far the most important constituents from the physiological stand- 
point are the meat bases to which the preparations owe their well-known 
stimulating properties. Indeed, a properly prepared extract has very 
little actual food value, but is rather to be regarded as a stimulant and 
condiment serving both purposes in an analogous manner to tea and 
coffee. 

Creatine and Creatinine, aside from their value as stimulants, are of 
importance, as was first pointed out by Micko, in distinguishing true 
meat extracts from yeast extracts, which formerly, if not at the present 
time, were used as substitutes. These are usually determined together 
and the results expressed in terms of creatinine (" total creatinine ") 
after dehydrolyzing the creatine with acid. 

Carnosine, Carnitine, and Methyl Guanidine, according to Krimberg, 
occur in meat extracts as well as in the living muscle. 

The Purine Bases of meat extracts have been exhaustively studied by 
Micko. I who found hypoxanthine in the largest amount while xanthine 
and adenine were present in smaller amounts. He was unable to find 
either guanine, which according to Kossel is present in meat, or carnine 
which Weidel § reported in American meat extract. The former Micko 
considers to have been eliminated in the manufacture of the extract while 
the latter he believes not to be present in either. Carnine and hypo- 

* Zeits. Unters. Nahr. Genussm., 14, 1907, p. 284. 

t Arch. Chem. Mikros., 9, 1916, p. 77. 

t Zeits. Unters. Nahr. Genussm., 6, 1903, p. 781; 8, 1904, p. 225. 

§ Ann. Chem. Pharm., 158, p. 353. 



244 FOOD INSPECTION AND ANALYSIS. 

xanthine are very similar in their reactions and the latter might easily 
be mistaken for the former although there could be no question of 
identity if nitrogen were determined, as carnine contains 28.57% and 
hypoxanthine 41,18%. In yeast extracts Micko found adenine as 
the chief purine base; guanine, hypoxanthine, and xanthine were also 
present, the quantities being in the order named, while carnine was not 
found. 

Products of Hydrolysis. — By hydrolyzing meat extracts, according to 
Fischer's method, Micko* obtained glutaminic acid, alanine, leucine, 
isoleucine, aspartic acid, and glycocol. In addition other amino acids 
were obtained but in too small quantities for identification. Hydrolysis 
of the precipitate obtained by salting out with ammonium sulphate showed 
that it consisted almost entirely of true proteoses and did not contain 
gelatin. The filtrate from the proteoses yielded on hydrolysis amino 
acids of which glutaminic acid and glycocol were the most abundant 
while alanine, leucine, and aspartic acid occurred in smaller amounts. 
Proline and phenyl- alanine were not found. Taurine not previously 
reported was isolated and identified. 

Chlorine in meat extract is usually calculated in terms of sodium 
chloride, which Richardson f points out is not scientifically accurate, since 
the chlorine derived from the meat exists chiefly if not wholly as potas- 
sium chloride. He considers that after allowing 0.06% of sodium chloride 
for every unit per cent of dry solid matter present any excess may be 
fairly considered as added salt. 

Analyses of both solid and liquid meat extracts by Micko,J Bigelow 
and Cook, § Street, || and Wright,1[ appear on pages 246 to 249. In a 
number of instances the results have been recalculated or rearranged to 
facilitate comparison. 

Meat Juices. — A true meat juice, as prepared by expressing the liquid 
portion of meat, is a food product of high nutritive value and differs 
markedly in this respect from liquid extract and similar preparations on 
the market, some of which have been sold with misleading claims. WTiile 
it is impracticable to concentrate a meat juice without precipitation or 

* Zeits. Unters. Nalir. Genussm., 5, 1902, p. 193. 

t Allen's Commercial Organic Analysis, Phila., 1914, 8, p. 394. 

J Zeits. Unters. Nahr. Genussm., 5, 1902, p. 193; 20, 1910, p. 537; 26, 1913, p. 321. 

§ U. S. Dept. of Agric, Bur. of Chem., Bui. 114. 

1 1 Conn. Agric. Exp. Sta., Rep. 1907-8, p. 606. 

1[ Jour. Soc. Chem. Ind., 31, 1912, p. 176. 



FLESH FOODS. 245 

alteration, the name meat juice is perhaps warranted in the case of some 
of the preparations now on the market, which unlike hquid extracts give 
strong tests for hemoglobin and contain considerable amounts of coag- 
ulable nitrogen. In view, however, of the difficulties of accurate classi- 
fication, juices and fluid extracts are included under the same head in 
the tables on pages 246 to 248. 

Peptones and Meat Seasonings. — Certain meat preparations, known 
in Germany as " Speisewiirzen," are made by digesting in various ways 
meat, or meat residues after extracting the soluble constituents, so as to 
obtain the constituents in a " predigested " condition and develop agree- 
able flavors. These preparations are generally known as " peptones " 
in English, although this term is in many, if not all, cases inappropriate 
in view of their composition. Etienne and Delhaye obtained an English 
patent in 1890 for preparing a " peptone " from meat by heating the 
pulp in an autoclave from 150 to 175° C, separating the liquid from the 
insoluble matter, and digesting the latter with hydrochloric acid until 
the fibers are destroyed. The hquid obtained by the acid treatment, 
after neutralizing with sodium carbonate, is added to the concentrated 
aqueous extract. Micko,* in following this process, obtained by the acid 
treatment of the extracted meat a product with little odor but a decided 
meaty flavor which appeared to be due to amino acids. He obtained 
similarly flavored products by the hydrolysis of casein and silk fibroin. 
Examination of commercial preparations, made by the hydrolysis of 
protein matter, showed that they contained no coagulable or insoluble 
proteins, little if any proteoses or peptones, but often considerable amounts 
of ammonia. The amount of phosphoric acid present depended on the 
protein material employed but compared with that present in true meat 
extract was usually greater. Peptones are commonly used in soup prep- 
arations, often in conjunction with true meat extract, and various vegetable 
extracts for flavors. 

Soy sauce, the characteristic seasoning of chop suey, although a vege- 
table product rich in carbohydrates, resembles in its other constituents 
seasonings prepared from meat. Like the peptones, it contains only a 
trace of purine bases and little or no total creatinine. Suzuki, Aso, and 
Mitarai f separated from two liters of this sauce the following constituents 
in the quantities (grams) named: alanine 6.6, leucine 6, proline 3, lysine 2.6, 



*Zeits. Unters. Nahr. Genussm., 26, 1913, p. 322. 
t Bui. Col. Agr. Tokyo. Imp. Univ., 7, 1907, p. 477. 



246 



FOOD INSPECTION AND ANALYSIS. 



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FOOD INSPECTION AND ANALYSIS. 






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250 FOOD INSPECTION AND ANALYSIS. 

ammonia 4.2, protein 5.4, formic acid o.i, acetic acid 0.4, lactic acid 3.2, 
and two new bases i and 0.2. Tyrosin, aspartic acid, substances resembling 
polypeptides, and cystin were also found. A process has been patented in 
Germany for preparing a similar seasoning from peas. 

Analyses. — Under the head of " Miscellaneous " are included in the 
tables on pages 246 to 248, especially on page 246, a. number of prepa- 
rations known as soup seasoning, etc., which were doubtless obtained in 
large part by the hydrolysis of meat residues or other protein substances. 
They are characterized by their low content of purine bases and total 
creatinine. 

Bouillon Cubes. — These are about the size of large dice. They are 
wrapped with tin foil and for the convenience of travelers are packed 
in metal boxes. They consist of various mixtures of meat extract, pep- 
tones, extracts of soup vegetables, salt, spices, and gelatin or some other 
stiffening material. A single cube mixed with boiling water suffices for 
a cup of bouillon which, although containing a very small amount of 
food material, furnishes a most agreeable concomitant for bread or dry 
biscuit and also a safe and palatable beverage when the character of the 
water is questionable. The chief value of analyses is not to show their 
nutritive value, which is obviously small, but from the percentages of total 
creatinine and purine bases to gain an insight into the proportion of meat 
extract present. The percentage of meat extract having been deter- 
mined by analysis, dependence must then be placed on the palate to 
determine the quality of the product. 

Analyses by Micko of bouillon cubes appear on page 246; those by 
Cook * on page 251 are of cubes bought in New York in 191 2. 

Kappeler and Gottfried f in analyses of 35 samples obtained the fol- 
lowing maxima and minima: water lo.o-i.i, protein 26.9-0.4, phosphoric 
acid 1.43-0.25, ash 83.7-56.8, salt 83.3-53.7, total creatinine 1.2-0, fat 
9.6-0, and sugar 14.7-0. 

Standards. — Micko,| after discussing the widely differing standards 
proposed by Sudendorf,§ Geret,|| Serger.^ and Lebbin,** suggests a mini- 
mum of 15% fat- free organic matter (with 15% total nitrogen) of which 

* Jour. Ind. Eng. Chem., 5, 1913, p. 989. 

t Zeits. Unters. Nahr. Genussm., 31, 1916, p. i. 

X Loc. cit. 

§ Zeits. Unters. Nahr. Genussm., 23, 1912, p. 577. 

II Ibid., 24, 191 2, p. 570; Kons. Ztg., 14, 1913, p. 5. 

II Kons. Ztg., 13, 1912, p. 378. 

**Ibid., 14, 1913, pp. I, 65. 



FLESH FOODS; 
COMPOSITION OF BOUILLON CUBES. 



251 



Brand. 


Solids. 


Organic 

Matter. 


Ether 
Extract. 


Ash. 


Sodium 
Chloride 

Equiv. 

to 

Chlorine. 


Phos- 
phoric 
Acid. 


Acidity 
cc. 

N/20 
NaOH 

Gram. 


Total 
Nitro- 
gen. 


Nitro- 
gen 
pptd. 
by Al- 
cohol 
from 
HCl 
Sol. 


Total 
Creat- 
inine. 


Behrend 

0x0 


96 

95 
96 
96 

95 
96 
96 

95 
96 

95 


60 
06 
OS 
87 
73 
05 
77 
81 
00 
44 


22.86 

2531 
28.41 
41.94 
45 23 
26.48 

33 00 
21.76 
21.91 

26. 24 


I 93 
310 
1.20 
1. 00 
1.44 
0.96 

3-79 
4.19 
458 
4-57 


73-74 
69 -75 
67.64 

54 93 
50.50 
69 -57 
63 77 
74 05 
74.09 
69.20 


72.13 
65.00 
62.15 
52.90 
49.26 
67.44 

5917 
72.22 
71.98 
65.00 


1.02 

I-5I 
1.83 
0.58 

0.54 
0.62 
1.69 
0.48 
0.41 
1-55 


6.20 
6.50 

915 
6.10 

730 
6.00 
9.68 
5 01 

4-75 
7.40 


2.19 
2.97 
3.62 
2. II 
2.36 
2.79 

3-67 
2.09 
2.11 
3.20 


0.13 
0.86 
0.76 
o.os 
0.02 
0.17 
0.56 
0.07 
0.05 
0.91 


0.84 
1.07 
1.67 
0.88 
0.92 
1.07 
1.07 
0.50 
49 
1.38 


Steero 

Burnham.. . . 
Sunbeam .... 

Armour 

Morris 

Standard .... 

Liggitt 

Knorr 



half is from meat extract, furthermore that for every ico parts of organic 
matter from meat extract there should be present at least 10 parts of 
total creatinine, i.i parts of purine nitrogen, and 11 parts of phosphoric 
acid (P2O5). Calculated as percentages of the material as purchased these 
limits would be as follows: total nitrogen 2.25^^, total creatinine 0.75% 
(nitrogen as creatinine 0.28%), purine nitrogen o.oS^f, phosphoric acid 
0.82%, and meat extract 12.5-15.0%. The author considers that both 
meat extract and peptones would contain about the same amount of 
nitrogen (15%) in the dry matter, but that total creatinine, purine bases, 
and phosphoric acid would be present in considerable amount only in 
the meat extract. Yeast extract contains even more purine nitrogen and 
phosphoric acid than meat extract, but the absence of total creatinine 
serves for its detection. He further notes that albumoses are much higher 
in meat extracts than in peptones, while on the other hand ammonia is 
decidedly lower. 

Beythien * considers that bouillon cubes should contain 15-20% 
of meat extract (0.6-0.8 gram per 4-gram cube) and a maximum of 65% 
of salt. Gerlach f places the minimum limit for meat extract at 7.5% 
(0.3 gram per 4-gram cube) but considers 65% a suitable maximum for 
salt. 



* Zeits. Unters. Nahr. Genussm., 31, 1916, p. 3^. 
t Chem. Ztg., 40, 19 16, p. 587. 



252 



FOOD INSPECTION AND ANALYSIS. 



Miscellaneous Preparations. — Under the head of " Miscellaneous " 
in the tables are included a variety of preparations containing various 
mixtures of meat extracts or other meat derivatives vi^ith protein sub- 
stances f.rom other sources, vegetable matter, spices, and other products. 
Some are foods for invalids while others are merely condiments. The 
amounts of meat extract can be roughly estimated from the creatinine 
content. 

Yeast Extracts. — The absence of creatine and creatinine and the 
presence of the purine bases (adenine, guanine, hypoxanthine, and xan- 
thine) in yeast extracts have already been noted under meat extracts. 
Analyses of three yeast extracts by Micko * are given in the following 
table : 

COMPOSITION OF YEAST EXTRACTS. 





Water. 


Mineral Constituents. 


Fat-free 
Organic 
Matter. 


Nitrogen. 




Total 
Ash. 


Sodium 
Chloride 
Equiv. to 
Chlorine. 


Phos- 
phoric 
Acid. 


Total. 


Pro- 
teose. 


Creatine 
and 
Creat- 
inine. 


Purine 
Base. 


Sitogen 

Ovos 


32.50 
53 67 
65 -93 


22.00 
16.87 
15-73 


10 -45 
10.85 


6 54 
2.79 
2. II 


45-50 
29,46 
18.35 


5-81 
2.99 
2.36 


0.21 







I. 14 
0.50 


X 


0.30 







The author calls attention to the small amount of proteoses (albumoses) 
and peptones and expresses an opinion that the nitrogen is probably in 
large part in the form of nucleoproteins. 

Standards. — The following standards were adopted by the U. S. Joint 
Committee in 1907. 

1. Meat Extract is the product obtained by extracting fresh meat 
with boiling water, and concentrating the liquid portion by evaporation 
after the removal of fat, and contains not less than 75% of total solids, of 
which not over 27% is ash, and not over 12% is sodium chloride (cal- 
culated from the total chlorine present), not over 0.6% is fat, and not 
less than 8% is nitrogen. The nitrogenous compounds contain not less 
than 40% of meat bases, and not less than 10% of creatine and creatinine. 

2. Fluid meat extract is identical with meat extract, except that it 
is concentrated to a lower degree, and contains not more than 75, and not 
less than 50% of total solids. 



* Zeits. Unters. Nahr. Genussm., 5, 1902, p. 193. 



FLESH FOODS. 253 

3. Bone extract is the product obtained by extracting fresh trimmed 
bones with boiling water and concentrating the liquid portion by evapo- 
ration after removal of fat, and contains not less than 75% of total solids. 

4. Fluid hone extract is identical with bone extract, except that it is 
concentrated to a lower degree and contains not more than 75 and not 
less than 50% of total solids. 

5. Meat juice is the fluid portion of muscle fiber, obtained by pressure 
or otherwise, and may be concentrated by evaporation at a temperature 
below the coagulating point of the soluble proteins. The solids contain 
not more than 15% of ash, not more than 2.5% of sodium chloride (calcu- 
lated from the total chlorine present), not more than 4 nor less than 2% 
of phosphoric acid (P2O5), and not less than 12% of nitrogen. The 
nitrogenous bodies contain not less than 35% of coagulable proteins, and 
not more than 40% of meat bases. 

6. Peptones are products prepared by the digestion of protein material 
by means of enzymes or otherwise, and contain not less than 90% of 
proteoses and peptones. 

7. Gelatin {edible gelatin) is a purified, dried, inodorous product of 
the hydrolysis, by treatment with boiling water, of certain tissues, as skin, 
ligaments, and bones, from sound animals, and contains not more than 
2% of ash and not less than 15% of nitrogen. 

ANALYSIS OF MEAT EXTRACTS, ETC. 

Determination of Water. — Dry from 2-20 grams of the material, 
according to the water content, in a flat-bottom dish in a boiling water 
oven to constant weight. It is well to dissolve pasty preparations in 
water and to use a sufficient amount of asbestos or sand to absorb the 
material. If fat is to be determined on the same portion employ a tin, 
or lead dish or Hoffmeister shell; if ash, a platinum or porcelain dish, 
omitting sand or asbestos. 

Determination of Ash. — Proceed as in the case of meats (p. 230). 

Determination of Fat. — Dry as described for the determination of 
water with asbestos or sand and extract with anhydrous ether in a con- 
tinuous extractor. Evaporate off the ether, dry the residue, and weigh 
as in the case of milk (page 121). 

Determination of Total and Ammoniacal Nitrogen. — Proceed as 
directed under meat (p. 225). 

Determination of Insoluble Protein.— Weigh a quantity of the material 
corresponding to about 10 grams of dry matter into a 500-cc. graduated 



254 FOOD INSPECTION AND ANALYSIS. 

flask. Add cold water, mix well, make up to the mark, and shake at 
intervals for an hour or until the material appears to have gone into solu- 
tion, and filter on a dry paper. Determine nitrogen in an aliquot of 
50 cc. of the filtrate, thus obtaining the amount soluble in cold water 
which, subtracted from the total nitrogen, gives the insoluble nitrogen. 
N X6.25 = insoluble protein. 

Determination of Coagulable Protein. — Evaporate 400 cc. of the 
filtrate obtained in the preceding section, to ico cc, neutralize, boil, filter, 
and determine nitrogen in the precipitate as in the Grindley and Emmett 
method (p. 229). Nx6.25 = coagulable protein (albumin). 

Make the filtrate up to 500 cc. and use aliquots for the determination 
of (i) proteoses, (2) tannin-salt precipitate, and (3) creatine and creatinine. 

Determination of Proteoses. — Bbmer Method.'^ — To a 50-cc. aliquot 
of the solution prepared as above, add i cc. of sulphuric acid (i : 4) and 
finely powdered zinc sulphate in small quantities with stirring until on 
long standing the precipitate of proteoses separates on the surface of the 
liquid and a small quantity of undissolved zinc sulphate settles to the 
bottom. Collect the precipitate on a paper free from nitrogen, wash with 
cold saturated zinc sulphate solution, keeping the funnel covered with 
a watch glass during filtration, and determine nitrogen in the precipitate 
without removal from the paper. Nx 6.2 5 = proteoses (albumoses). 

Determination of Tannin-Salt Precipitate. — Schjerning Method Modi- 
fied by Bigelow and Cook.'\ — Concentrate 100 cc. of the filtrate from the 
coagulable proteins to 20 cc. or less, transfer to a loo-cc. graduated flask, 
add 50 cc. of sodium chloride solution (300 grams per liter), and shake 
thoroughly. Place in an ice box at about 12° C. and after the temperature 
becomes constant add 30 cc. of 24% tannin solution (also at ice-box tem- 
perature), make up to the mark, and shake. Keep in the ice box over 
night, filter at ice-box temperature, through a dry paper, and determine 
nitrogen in 50 cc. of the filtrate. Correct for the nitrogen in the reagent, 
as found by a blank determination, and calculate the percentage in the 
material. The nitrogen thus obtained includes that present as meat 
bases, except about one-quarter of the creatine present in the tannin- 
salt precipitate, and as ammonia. Bigelow and Cook estimate peptones 
by adding the percentages of tannin-salt filtrate, insoluble, coagulable 

* Zeits. anal. Chem., 34, 1895, p. 562. 

t Jour. Amer. Chem. Soc, 28, igo6, p. 1496. Schjerning himself (Zeits. anal. Chem., 
39, 1900, p. 562) regarded tannic acid as of little value in the separation of the proteins. In 
his method for total protein nitrogen he uses uranium acetate. 



FLESH FOODS. 255 

and proteose nitrogen, deducting from the total nitrogen, and multiplying 
the difference by 6.25, although the figure probably represents peptoids, 
formed by the action of the hot solution on gelatin, and polypeptides. 
True peptones are apparently not present as the tannin-salt filtrate sel- 
dom gives the biuret reaction. See also page 247. 

Bigelow and Cook suggest that a correction be introduced for the 
creatine after determining the amount present before and after precipi- 
tation with tannin-salt reagent. Street believes this correction imprac- 
ticable owing to the difficulty of removing tannin from the filtrate, the 
slightest trace of which interferes with the color reaction. 

Determination of Creatine and Creatinine. — Folin Method Modified 
by Benedict and Myers.^ — This method is based on the color produced 
by creatinine with picric acid in alkaline solution (Jaffe reaction). Place 
50 cc. of the filtrate from the coagulable protein, obtained as described 
above, in a loo-cc. graduated flask, boil down to about 10 cc, add 10 cc. of 
normal hydrochloric acid, and heat in an autoclave 30 minutes at 117-119°. 
Cool, add 10 cc. of normal sodium hydroxide solution, make up to the 
mark, and shake. Pipette 25 cc. into a 500-cc. graduated flask, add 30 
cc. of saturated (1.2%) picric acid solution, and 10 cc. of 10% sodium 
hydroxide solution, make up to the mark, and shake. Compare in a 
colorimeter with a half-normal potassium bichromate solution (24.54 
grams per liter) set at 8 mm, on the scale, which corresponds to 9.88 mg. 
of pure creatinine. If the reading of the unknown varies more than 
2 or 3 mm. from 8 mm. prepare a new solution, using an aliquot that will 
give approximately that reading. From the results obtained calculate 
the creatinine which includes not only the creatinine that exists ready 
formed in the product, but also that obtained by dehydrolyzing the 
creatine. 

If separate figures for both bases are desired, place an aliquot of the 
filtrate from the coagulable nitrogen directly in a 500-cc. graduated flask, 
add 15 cc. of the picric acid solution and to cc. of the sodium hydroxide 
solution, make up to the mark, shake, and compare with the bichromate 
solution as before. Calculate the percentage of creatinine and subtract 
from the percentage of total creatinine previously obtained and the dif- 
ference is the creatine in the material calculated in terms of creatinine. 
To obtain the nitrogen corresponding to either base or the sum of the 
two, expressed in each case as creatinine, multiply by 0.372. To convert 

* Amer. Jour. Phys., 18, 1907, p. 397. 



256 FOOD INSPECTION AND ANALYSIS. 

creatine expressed as creatinine into true percentage of creatine multiply 
by 1.16. 

If an autoclave is not at hand, invert by the Baur and BarschaU Method * 
as follows: Evaporate 200 cc. of the filtrate from the coagulable protein 
to a volume of less than 38 cc, transfer to a graduated cylinder, and 
make up to 38 cc. v^ith the rinsings. Transfer to a loo-cc. graduated 
flask, rinsing with 17 cc. of normal hydrochloric acid, and heat 4 hours 
under a reflux condenser in a boiling water-bath. Neutralize the acid 
with 17 cc. of normal sodium hydroxide solution, make up to 100 cc, and 
proceed as above described, using, however, smaller aliquots because of 
the greater concentration of the solution. Micko obtains practically the 
same results by the two methods of dehydration. 

Sudendorf and Lahrmann t find that in bouillon cubes the presence 
of yeast extract, caramel, tomato juice, and other substances give mis- 
leading colors in the determination of creatinine and therefore lead to 
wrong conclusions as to the content of meat extract. They eliminate 
this source of error by preliminary treatment with potassium permanganate, 
as proposed by Lendrich and Nottbohm, as follows: 

Prepare a 10% solution, filter to remove fat, and place 10-20 cc. of 
the filtrate in a 75-cc. capsule, add 10 cc of normal hydrochloric acid, 
and evaporate to dryness on a boiling water-bath. Dissolve the residue 
in water, neutralize to litmus with N/2 sodium hydroxide solution, rinse 
into an Erlenmeyer flask, dilute to 75 cc, and run in ]% potassium per- 
manganate solution containing 2.5% sodium chloride, drop by drop with 
shaking until a red color persists for several minutes. If the solution 
becomes too thick, dilute with water. Destroy the excess of potassium 
permanganate by adding drop by drop 3% hydrogen peroxide solution 
containing i cc of glacial acetic acid per 100 cc. Heat on a boiling water- 
bath 5-10 minutes until the manganese oxide separates in flocks. Filter 
with the aid of suction, wash until chlorine is removed, evaporate to small 
volume, rinse into a 500-cc. flask, using about 20 cc. of water, cool, then 
treat with 10 cc. of 10% sodium hydroxide solution and 20 cc. of saturated 
picric acid solution. After 5 minutes make up to the mark and proceed 
as above described. 

Determination of Purine (Xanthine) Bases. — Kriiger-Micko Method. I — 
To 5 grams of the material add ico cc. of water and 10 cc of sulphuric 

* Arb. Kaisl. Gsndhtsamt., 24, 1906, p. 552. 
t Zeits. Unters. Nahr. Genussm., 29, 1915, p. i. 
t Ibid., 5, 1902, pp. 204, 209; 26, 1913, p. 334. 



FLESH FOODS. 257 

acid (1:3), and boil under a reflux condenser 3 hours. Neutralize with 
sodium hydroxide solution, add 20 cc. each of copper sulphate solution 
(130 grams per liter) and saturated sodium bisulphite solution (200 grams 
per liter), and boil 2-3 minutes. After cooling, filter and wash with 
water containing a little of both the reagents to prevent oxidation. Remove 
paper and filter to a flask, mix well with water, and add sufficient hydro- 
chloric acid to dissolve the precipitate. Heat to boiling to reduce the 
filter to a pulp and remove sulphur dioxide, and precipitate the copper 
with hydrogen sulphide gas. After some hours filter on a close filter 
and wash with water containing a little hydrogen sulphide and a few drops 
of hydrochloric acid. 

Evaporate the filtrate to small volume, take up in hot water if neces- 
sary, with the addition of a few drops of hydrochloric acid, nearly neu- 
tralize with ammonia, dilute to 70 cc.^ and after cooling add 20 cc. of 
ammonia water (i : i). 

Precipitate with a mixture of 25 cc. of 10% silver nitrate and 25 cc. 
of I • I ammonia water, added drop by drop with stirring. After standing 
some hours in a dark place, filter, wash three times with 4% ammonia 
water (i ;6), then with water, containing 2.5 cc. of strong ammonia per 
JOG cc, until free from nitrates. Wash out the ammonia with 70% 
alcohol, dry in a water oven, and determine nitrogen. 

The results are most accurately expressed as percentage of purine 
nitrogen, since the factors for the different purine bases differ somewhat. 
Some authors calculate the results in terms of xanthine, using the factor 
2.71. 

Other Methods for Separating Meat Nitrogenous Compounds. — Among 
the methods which need be but briefly mentioned, as they have been 
largely displaced in recent years, are those of Liebig (alcohol solubility), 
Bruylants * (fractional precipitation by various strengths of alcohol), 
Hehner t (precipitation by methylated spirits), Rideal and Stewart J 
(precipitation by chlorine), Allen and Searle § (precipitation by bromine), 
and various methods based on precipitation by phosphotungstic acid. 

Determination of Acidity. — Titrate with N/io alkali a weighed por- 
tion of the material dissolved in water, using phenolphthalein or delicate 
litmus paper as indicator. Calculate as lactic acid. 

* Jour. Pharm. Chem., 5, 1897, p. 515. 
t Analyst, 10, 1885, p. 221. 
X Ibid., 22, 1897, p. 228. 
§ Ibid., 22, 1897, p. 259. 



258 FOOD INSPECTION AND ANALYSIS. 

Determination of Coagulation Point. — Dilute with water to over- 
come the influence of coloring matter and other interfering substances. 
Place in a test tube 2 cm. in diameter and introduce a thermometer through 
a perforated cork. Heat the test tube in a beaker of water, stirring the 
solution with the thermometer during the heating, and note the coagulation 
point. 

Determination of Sugars. — W. B. Smith' Method.*— To a solution of 
5 grams of the meat extract in 25 cc. of water add an excess (4-6 grams) 
of solid picric acid and an excess (40-60 cc.) of 2o9( phosphotungstic acid 
solution. Mix, make up to 100 cc, shake, and filter through a dry paper. 
To 60 cc. of the filtrate add 3 cc. of concentrated hydrochloric acid, make 
up to 66 cc, and filter quickly, Determine copper reducing power of 
the filtrate both directly and after inversion, neutralizing in both cases. 
See Chapter XIV. 

Determination of Glycerol. — This substance is sometimes used as 
a preservative for fluid preparations. Bigelow and Cook f evaporate 
to dryness, extract with acetone, remove the meat bases by precipitation 
with silver nitrate, followed by phosphotungstic acid, and determine 
the glycerin in the filtrate by Hehner's method. | 

Detection of Preservatives in Meat Extracts. — Boric acid is some- 
times used as a preservative in these preparations, and is tested for by 
the usual methods (Chapter XVIII). 

GELATIN. 

Gelatin may be regarded as a food adjunct rather than as a food. 
The food value of preparations containing gelatin is due chiefly to the 
sugar and other constituents as the amount of gelatin is small and what 
is present serves chiefly as fuel and not as a substitute for true proteins 
since a diet containing gelatin as the only nitrogenous constituent will not 
support life. 

The product used for food should be obtained from clean material 
such as bones, calves' feet, etc. It consists essentially of glutin and its 
derivative ghitose. 

According to the U. S. Standard it should contain at least 15% of 
nitrogen and not more than 2% of ash. 

* Jour. Ind. Eng. Chem., 8, 1916, p. 1024. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 114, p. 42. 

J Jour. Soc. Chem. Ind., 8, 1889, p. 4. 



FLESH FOODS. 259 

Common impurities are sulphur dioxide and traces of arsenic. Copper, 
zinc (indicating glue stock preserved with zinc salts), and lead are occa- 
sionally present. 

In detecting sulphur dioxide, Alexander * recommends distillation 
and determination by the gravimetric rather than the iodimetric method. 

FISH. 

General Composition.— Fish resembles meat both structurally and in 
the nature of its constituents, but differs from it in the relative proportions 
of its various components. Thus, there is considerably more refuse 
matter such as skin and bones in fish than in meat, and in the edible 
portion of fish the amount of water and ash is usually greater and of fat 
is less. Comparing the nitrogenous components of each, we find in fish 
more of the gelatin- yielding matter (collagen) and less of the extractives 
than in meat. There is much less haemoglobin or allied coloring sub- 
stance in the flesh and blood of fish than in meat, which accounts for the 
white color usually characteristic of the former. Certain fish, however, 
like the salmon, probably owe their distinctive color to a pigment be- 
longing to the lipochrome class, while the colored areas in salt herring are 
due, according to Griebelf to a red pigment, soluble in trimethylamin 
and similar weak bases, derived from the eyes of marine animals eaten 
by the fish. The common belief that fish contains markedly more phos- 
phorus and is a better brain food than meat is not in accordance with 
the facts, although fish roe and milt are rich in phosphates and lecithin 
as well as in proteins. As regards digestibility, fish is regarded as superior 
to meat although certain varieties rich in fat and all crustaceans are excep- 
tions to the rule. 

According to Atwater and Bryant J the composition of different vari- 
eties of true or vertebrate fish is as given on page 260. 

Fat Content of Fish.— Hutchison § classifies fish as follows with ref- 
erence to their content of fat: (i) lean, with less than 2% of fat, such as 
cod and haddock; (2) medium, with 2-5% of fat, such as halibut and 
mackerel; (3) fat, with more than 5% of fat, such as salmon, eels, turbot, 
and herring. 

* Jour. Amer. Chem. Soc, 29, 1907, p. 783. 

t Zeits. Unters. Nahr. Genussm., 19, 1910, p. 424. 

X U. S. Dept. of Agric, 0£f. of Exp. Sta., Bui. 28, p. 47 el seq. 

§ Food and the Principles of Dietetics. 



260 



FOOD INSPECTION AND ANALYSIS. 



COMPOSITION OF FISH. 



Refuse. 



Water. 



Protein. 



NX 
6.25. 



By 
Differ- 
ence. 



Fat. 



Ash. 



Fuel 
Value 

per 
Pound. 



Bass — 
Bluefish — 
Cod— 
Eel- 
Haddock— 
Halibut- 
Herring — 
Mackerel- 
Perch — 
Pickerel — 
Salmon — 
Shad- 
Skate— 
Smelt- 
Trout— 
Turbot- 
Whitefish- 



edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
-edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
-edible portion, 
as purchased., 
edible portion - 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
-edible portion, 
as purchased. . 



5S-0 



48.6 

52-5 



20.2 
51.0 



17.7 
42.6 



44-7 
62.5 



47-1 
34-9 



50.1 
51.0 



41.9 
48.1 



47-7 

53-5 



77-7 
35-1 
78-5 
40-3 
82.6 

38.7 
71.6 

57-2 
81.7 
40.0 

75-4 
61.9 

72-5 
41.7 
73-4 
40.4 

75-7 
28.4 

79-8 
42.2 
64.6 
40.9 
70.6 
35-2 
82.2 
40.2 
79-2 
46.1 
77-8 
40.4 
71.4 

37-3 
69.8 

32. 5 



2.8 
I.I 
1.2 
0.6 
0.4 
0.2 
9.1 
7-2 

0-3 
0.2 

5-2 

4-4 
7-1 
3-9 
7-1 

4-2 

4.0 
1-5 
0-5 
0-3 
12.8 

8.9 

9-5 
4-8 
1.6 
0.7 
1.8 
i.o 
2.1 
I.I 
14.4 
7-5 
6.5 
3-0 



1.2 
0-5 
1-3 
0.7 
1.2 
0.6 
1.0 
0.8 
1.2 
0.6 
1.0 
0.9 

1-5 
0.9 
1.2 
0.7 
1.2 
0.4 
I.I 
0.6 

1-4 

0.9 

1-3 
0.7 
I.I 
0.6 

1-7 
1.0 
1.2 

0.6 

1-3 
0.7 
1.6 
0.7 



465 
200 
410 
210 
325 
165 
730 
580 

335 
165 
565 
470 
660 
375 
645 
365 
530 
200 

370 
210 

950 
660 

750 
380 
400 
195 
405 
230 

445 
230 
885 
460 
700 
325 



Clark and Almy * note considerable variation in the fat of migratory 
fish such as shad and mackerel, due to season, age, time of spawning, 
and feeding, but little in bottom fish such as haddock and flounders. 

Rohrig t bases his distinction of sardines from French and Brabant 
anchovies on the differences in fat content, the former containing 7-10%, 
the latter 0.8-3.10%. This distinction is of no value in the examination 
of sardines in oil. 

Behre and Frerichs J employ the percentage of fat and the fat con- 

* Jour. Biol. Chem., 29, 191 7, xxii. 

t Ber. Chem. Unters. Anst. Leipzig, 1910, p. 13. 

X Zeits. Unters. Nahr. Genussm., 24, 191 2, p. 676. 



FLESH FOODS. 



261 



stants as a means of distinguishing anchovy butter from imitations made 
from herring and other foreign fish. The following data are given by 
them : 





Number of 
Samples. 


Water. 


Fat. 


Iodine Number 
of Fat. 


Refraction of 
Fat, 40° C. 


Butter . ... 




13 40 
65.07-74.46 
52.40-56.20 


83 SI 

I. 14- 1.36 

10. 62-11. 76 


41.38 
138. 7-176. 7 
loi . 1-109. I 


45 
74-75 
64-66 


Anchovies . . . 
Herring 


3 

2 



From the above figures the authors named conclude that anchovy 
butter with less than 10% of fat probably contains no herring; if the 
fat content reaches 15% the iodine number should not be over 60 and the 
refraction over 50. 

Characteristics of Fresh Fish. — Fish of all kinds should be eaten 
when perfectly fresh, as it undergoes decomposition much sooner than 
meat when killed. While with meat aging is often beneficial to bring 
out requisite tenderness and flavor, in the case of fish deterioration begins 
almost immediately after death. Even though certain varieties of fish 
may be kept firm and wholesome for some days on ice, the flavor is dis- 
tinctly impaired by long keeping. When, however, fish is frozen while 
perfectly fresh changes are arrested. Smith * could detect no appre- 
ciable change in composition, food value, or sanitary condition in fish 
frozen for 9 months and Perlzweig and Gies f found none in fish frozen 
2 years. Fish that is not perfectly firm to the touch, or that has abnor- 
mally dry scales, or that shows blubber at the gills, or that possesses the 
marked odor that accompanies incipient decomposition, should not be 
used as food. 

The Roe of shad, cod, and other fish is eaten fresh and is valuable 
not only for its protein, fat, and carbohydrates but also for its lecithin 
and cholesterol. Fish milt is also used for food. 

Caviar is salted sturgeon roe. The best grades are obtained from 
southern Russia, inferior grades from the river Elbe. Salted cod roe, a 
common substitute, is characterized by its lower fat content. From the 
data available it is difficult to give a minimum limit for fat in caviar. 
Analyses by Rimini J and Grossfeld § give a minimum fat content of 
14.67% for true caviar and a maximum fat of 4.44% for cod roc pre- 

* Biochem. Bui., 3, 1913, p. 54. 

t Ibid., p. 69. 

t Staz., sper. agrar. Ital., 36, 1903, p. 249. 

§ Konigls Chemie der Mensch. Nahrungs- und Genussmittel 4 Aufl. Ill, 2, p. 159. 



262 



FOOD INSPECTION AND ANALYSIS. 



pared in a similar manner. Buttenberg's analyses,* however, show a 
minimum of 7.59% of fat in true caviar and 1.27% of fat in a single sample 
of salted cod roe. 

Crustaceans and MoUusks. — These differ from the meats and com- 
mon fish in that they contain considerable carbohydrate (glycogen) but 
no creatine or creatinine. The lobster and crab are nearly alike in com- 
position, the flesh being made up of coarse, dense, thick-walled fibers. 

Pay en gives the following composition of the fiesh and body of lobster: 



Flesh (contained in 
Claws and Tail). 



Body (consisting 
mainly of Liver). 

84.31 

12.14 

1. 14 



Water 76.6 

Protein 19-17 

Fat 1. 17 

Clams and Oysters are low in solid nutriment, and are more digestible 
when eaten raw than cooked. Oysters contain 3% or more of glycogen, 
and distinct amounts of copper the physiological role of which is analogous 
to that of iron in the blood of higher animals. 

The following analyses are from Atwater and Bryant's compilation if 

COMPOSITION OF SHELL FISH, ETC. 



Clams- 
Crabs— 
Lobster — 
Mussels- 
Oysters— 

Scallops — 
Terrapin — 

Turtle- 
Frogs' Legs- 



edible portion, 
as purchased . . 
edible portion . 
as purchased . . 
edible portion . 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
as purchased . . 
edible portion, 
as purchased . . 
edible portion, 
as purchased. . 
-edible portion, 
as purchased . . 



Refuse. 



41.9 



52.4 
61. 7 
46 7 
81.4 



75-4 
76.0 
32.0 



Water. 



85 
49 
77 
36 
79 
30 
84 
44 
86 
16 

3 

74-5 
18 3 
79 8 
19, 2 
83 7 
569 



Pro- 
tein. 
NX 
6.25. 



8.6 

S-o 
16.6 

7.9 
16.4 

5-9 
8.7 
4.6 
6.2 
1 .2 
14.8 
21 . 2 

5-2 
19.8 

4-7 
iS-5 
10.5 



Fat. 



Car- 
bohy- 
drates. 



1 .0 
0.6 
2.0 
0.9 
1.8 
0.7 
I . I 
0,6 
1 .2 
0.2 
o. I 

3 5 
0.9 

o.S 
o. I 

O. 2 
O. I 



1. I 

1.2 
0.6 
0.4 
O. 2 

41 

2. 2 

3-7 

0.7 

3-4 



Ash. 



2.6 
1-5 
31 
1-5 
2. 2 
0.8 
1.9 
i.o 
2.0 
0.4 
1.4 
1.0 

O. 2 
1.2 

03 
I .0 
0.7 



Fuel 
Value 

per 
Pound. 
Cals. 



240 
140 
415 
195 
390 
140 
28s 
150 
235 

45 
345 
545 
135 
390 

90 

295 
200 



* Ber. Hyg. Inst. Hamburg, 1900-2, p. 13. 

t U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 28, p. 52, 



>LESH FOODS. - 263 

Canned Fish. — Modern methods of canning are particularly valu- 
able in the fish industry owing to the perishable nature of the product 
and often the remoteness of the supply. With us salmon, tunny, and 
lobster are the best known varieties preserved by simple canning, while 
sardines and herring are the most popular fish treated by salting, 
smoking, or the addition of oil, spices, and various condiments previous to 
canning. 

While the packing of decomposed fish, spoilage due to imperfect 
sterilization, and the substitution of inferior varieties have not been un- 
common, the detection of these irregularities or defects, now fortunately 
infrequent, falls to the bacteriologist or zoologist; the examination for 
foreign oils and tin, however, is a frequent duty of the chemist. Olive 
oil is used in packing the best grade of French and Norwegian sardines, 
but cotton seed oil is commonly substituted in the preparation of the 
cheaper American product, the nature of the oil being distinctly stated 
on the label, thus complying with the requirements of food laws. 

Tin^ in the form of salts dissolved from the can, is still a matter of 
concern, although packers have made serious effort to reduce the amount 
by using lacquered cans and paper or veneer linings. In samples of 
sardines put up in mustard, vinegar, and oil, the Massachusetts Board, 
has found as high as 0.376 gram of tin in a half-pound can, the corrosion 
of the can being very marked. Crustaceans, because of their content 
of free amino compounds, act with special avidity on tin. Bigelow and 
Bacon * found that monomethylamin in canned shrimps attacks the can 
as do free amino acids in certain vegetables. 

The United States Government, pending further investigation, has 
allowed 0.300 gram of tin per kilo in canned fish, as well as in canned 
meats, vegetables, and fruits (F. I. D. 126). The unavoidable amount 
of tin present, however objectionable, is more than offset by the advan- 
tages of the canning system. For the detection of tin see Chapter 
XXL 

Salted and Smoked Fish. — Preservation by drying, salting, or smoking 
as well as a combination of two or all of these methods, is as ancient as 
canning is modern. While it is of first importance that the fish is true 
to name, sound when packed, and kept sound by proper handling, the 
chemist is chiefly concerned with the examination for colors and preser- 
atives as noted on page 265. 



Jour. Ind. Eng. Chem., 3, 191 1, p. 832. 



264 FOOD INSPECTION AND ANALYSIS. 

Floating of Shellfish. — Oysters and other shellfish, either in the shell, 
or, more commonly, after shucking, are often subjected to " floating " 
or " drinking " in fresh or brackish water or else shipped in direct con- 
tact with lumps of ice. Both practices cause the shellfish to greatly 
increase in size, owing to the absorption of an undue amount of water, 
and if not labelled " floated " the product is adulterated under the federal 
law and the laws of certain states. 

It is, however, not regarded as improper to drink oysters in water of 
a saline content equal to that in which they will grow to maturity or to 
wash the shucked oysters in unpolluted, cold or iced water for the mini- 
mum time required for cleaning and chilling. After washing they should 
be drained and packed for shipment in tight receptacles surrounded by 
ice but protected from the absorption of the water resulting from the 
melting of the ice. 

Nelson advocates the floating of oysters in clean water with a lower 
salt content than that of the beds because (i) dirt is eliminated, (2) the 
volume of flesh is increased, (3) a better color and texture are secured, 
(4) shrinkage is decreased, and (5) the water content during transporta- 
tion and storage is retained. 

Often shellfish is polluted by growing or floating in impure water, 
handling under insanitary conditions, or packing in unclean receptacles. 

As oysters cannot reach the consumer in satisfactory condition it 
shipped in their own liquor, the loss of food constituents on draming comes 
up for consideration. Baylac * reports in a liter of the liquor about 2 
grams of albumin as well as determinable amounts of urea, ammonium 
salts, and inorganic matter. The amount of organic matter in the liquor 
from Mediterranean oysters is greater than in that of oysters from the 
ocean. 

Scallops. — According to the Maine Experiment Station, f scallops 
properly handled should contain not less than 20% of dry matter. The 
following is a summary of analyses of soaked and unsoaked scallops by 
Sullivan,J the swelling of the meats being sufficient in some cases to make 
4^ gallons fill a 7-gallon keg: 

* Comp. rend. soc. biol., 62, 1907, p. 250. 

t Offic- Insp., 55, 1913, p. 149. 

X Amer. Food Jour., 10, 1915, p. 472. 



FLESH FOODS. 



265 





Unsoaked (31 Samples). 


Soaked (12 Samples). 




Max. 


Mm. 


Aver. 


Max. 


Min. 


Aver. 


Solids 

Protein 

Ash 


24.17 

15.69 

1. 81 


19. 21 

12.62 

1-33 


22.48 

14-38 
1.56 


19.64 

11.80 

I. 17 


14.18 
9.06 
0.93 


16. 20 

10.57 

1.02 



Clams. — At the Maine Station it was found that the drained meats of 
clams, which contained when opened 24.990 of sohd matter, took up on 
soaking over night in salt water sufi&cient liquid to reduce the percentage 
of dry matter to 15.3. While it is recognized that clams will not keep 
in their own liquor, it is insisted that they be rinsed not longer than i 
minute in cold water or else 2 minutes in hot water, followed by 2 minutes 
in cold water. 

Preservatives in Fish and Oysters. — Boric acid and borax in mixturfe 
and sodium benzoate form the most common preservatives of salt dried 
fish and of oysters. In the case of salt codfish, the preservative is sprinkled 
on the surface.* Such surface application is allowed under the laws 
of some states, as for example, Massachusetts, and under the federal law, 
provided directions for the removal of the preservative are given on the 
package. In opened oysters sold in casks and kegs, boric mixture has 
been used commonly in solution in the oyster liquor, but is now infre- 
quent. Ishida t calls attention to the presence of a trace of formalde- 
hyde in fresh crab meat and distinct amounts after being preserved 8 months. 

Artificial Colors of the coal-tar group are used to give smoked fish a 
rich brown color. The New York City Board of Health has brought 
to notice the coloring of cheaper fish in imitation of salmon. 

Methods of Analysis. — These are similar to the methods given for 
meat. 

CONCENTRATED FOODS. 

Under the name of " condensed " or " concentrated foods " or *' emer- 
gency rations " a number of canned preparations are sold for the use of 
campers, travelers, armies in the field, etc. These consist usually of 
mixtures of dried ground meats and vegetables, pressed together in com- 
pact form, and preserved in tin cans. The claims made for the food value 
of these preparations are, as a rule, extravagant and erroneous, as shown 



* Bitting, U. S. Dept. of Agric, Bur. of Chem., Bui. 133, 1911. 
t Jour. Pharm. Soc. Japan, 422, 1917, p. 300. 



266 



FOOD INSPECTION AND ANALYSIS. 



by Woods and Merrill,* who give the following analyses of some of these 
foods: ' 



Net 
Weight 
Con- 
tents. 



Weight of Materials in Package. 



Water. 



Pro- 
teins 



Fat. 



Carbo- ] 

hy- Ash. 
drates. 



Total 
Fuel 
Value. 



Ration cartridge, pea, beef, etc 

Blue ration campaigning food, a... 
" b.. 

Red ration campaigning food, a 

" '' " b.... 

Ration cartridge, potatoes, beef, etc 

Emergency ration, a 

"6 

Emergency ration, a 

" b 

Nao meat food 

Army rations 

Standard emergency ration 

" " "a 

" b , 

Arctic food • 

Tanty emergency ration 

F-A Food Company 's stew 



Grams, 

241 

i6g 

78 

122 

77 
283 
120 

113 
121 
127 

437 
661 
418 
270 
49 
423 
475 
964 



Grams. 


Grams. 


34-2 


52-9 


70-1 


37-5 


1.0 


^-6 


33-8 


26.2 


1.2 


5-0 


117.9 


62.3 


14.2 


56.1 


1.9 


8.2 


4-5 


71.8 


5-7 


8-3 


231-3 


56.9 


420.2 


101.2 


23.6 


129.6 


17.0 


50.6 


o-S 


3-2 


30-7 


75-1 


313-5 


60.2 


638.0 


149.2 



Grams. 

42.0 

9.0 

23.1 

18.5 
23.0 
12.6 
29.6 

32-7 
32.6 

15-3 
90.1 

84-3 
90-5 
54. « 
10. 5 

167.3 
.6 

"4-5 



Grams. Grams. 



98.0 


13-9 


37-9 


8-5 


46.9 


1-4 


37-8 


5-7 


46.6 


1.2 


76.4 


13-8 


II. 9 


7-8 


68.0 


2.2 


6-7 


5-4 


94-8 


2.9 


46.2 


12.5 


47-9 


7-4 


160.3 


14.0 


137-0 


10.6 


34-0 


0.8 


119. S 


30.1 


41.9 


10.8 


52-5 


9.8 



Gals. 

1071 

432 

436 

496 

424 

772 

617 

622 

776 

588 

1328 

1542 

2198 

1402 

254 
2430 
1482 
2460 



* Maine Exp. Sta., Bui. 75, p. 103. 



CHAPTER DC. 



EGGS. 



Nature and Structure. — Though eggs of \'arious birds are used to 
some extent as food, it is the egg of the hen that is in universal use for 
this purpose, and therefore the one which is here for the most part dis- 
cussed, bearing in mind that the structure and composition of all varieties 
of birds' eggs are closely analogous. 

Fig. 60 shows the longitudinal section of a hen's egg. 

J i g 




I 



Fig. 60.— Longitudinal Section of a Hen's Egg. a, Shell; b, Double Membrane of Shell; 
c, Air-chamber; d, Outer, or Fluid Albuminous Layer; e, Thick, Middle Albuminous 
Layer; /, Inner Albuminous Layer; g, Membrane of the Chalaza; hh, the Chalaza; 
i, Vitelline Membrane; j, Germ; k, Yolk; I, Latebra. (After Mace.) 

Weight of Eggs. — The average weights of whole and parts of hens' 
eggs, as given by Langworthy * and Serono and Palazzi f (the latter for 
1000 eggs), are as follows: 





Langworthy, 
grams. 


Serono and Palazzi, 
grams. 


Shell 


6 

18 


7 
32 
19 


White 

Yolk 


Total 


57 


S8 



* U. S. Dept. Agric, Farmers' Bui. 128, 1901. 
t Arch. farm, sper., 11, p. 553. 

267 



268 



FOOD INSPECTION AND ANALYSIS. 



The data given in the following table were obtained by Woods and 
Merrill:* 



AVERAGE WEIGHTS OF EGGS AND PARTS AS PREPARED FOR ANALYSIS. 





Weight 

as 
Received. 




Weight Boiled. 




Shell 
(Reiuse). 


White. 






Shell 
(Refuse). 


White. 


Yolk. 


Total. 1 


Yolk. 


Turkey 

Goose 

Duck 

Guinea fowl. . . 


Grams. 

105-5 

190.4 

70 6 

40.2 


Grams. 
II. 7 
24.1 

7-2 

5-6 


Grams. 
60.1 
98-5 
36.5 
20.9 


Grams. 

30-9 
64.8 
24.4 
12.5 


Grams. 

102.7 

187.4 

68.1 

39-0 


Per Cent. 

11. 4 

12. 5 
10.6 
14.4 


Per Cent. 

56-5 
52.6 
53-6 
53.6 


Per Cent 

30-1 
34.6 
35-8 
32.C 



'Shrinkage due to loss in preparation and cooking. 



Proximate Composition. — In the following table appear analyses by 
Woods and Merrill of the samples described above, also the average of 
analyses of hens' eggs taken from Atwater and Bryant's Compilation: 



COMPOSITION OF EGGS. 



Turkey- 



Goose — 



Duck- 



white 

yolk 

entire edible portion.. 

as purchased 

white. , 

yolk 

entire edible portion.. 

as purchased 

white 

yolk 

entire edible portion.. 

as purchased 

Guinea fowl — white 

yolk 

entire edible portion,. 

as purchased 

white 

yolk 

entire edible portion.. 
as purchased 



Hen— 



ss 



13-8 



14.2 



^2>-7 



iti.g 



Protein. 



go 

.■sx 



1-5 
7-4 
3-4 
1.6 
1.6 

7-3 
3-8 

i-S 
I.I 
6.8 
i-Z 
1-5 
1.6 
6.7 
3-5 



5 « 



12.5 
17.6 
14.2 
12.2 
12.9 
18.4 

15-1 
12.9 
12.2 
16.8 
14.0 
12. 1 
12.6 
17-3 
14-3 
II. 9 
13.0 
16. 1 
14.8 
I3-I 



Trace 
32:5> 
II. 2 

9-7 

Trace 

36.2 

14.4 

12.3 

Trace 

36.2 

14-S 

12.5 

Trace 

31-8 

12.0 

9-9 

0.2 

33-3 

10-5 

9-3 



0.8 
1.2 
0.9 
0.8 
0.8 

1-3 
i.o 
0.9 
0.8 



o.» 

1.2 
0.9 
0.7 
0.6 
1. 1 
1.0 
0.9 



§9 

.2 o 

> u 

_ V 

a) Q, 

3 



Cal. 

325 
1875 

850 

735 
330 
1975 
985 
860 

315 
1980 

985 
880 

325 
1800 

875 
730 
250 

1705 
720 

635 



* Maine E.xp. Sta., Bui. 75, 1901. 



EGGS. 269 

Ash. — The mineral content of the egg is thus shown by Konig: 
COMPOSITION OF THE ASH OF EGGS. 





Ash of 
the Dry 

Sub- 
stance. 


Potash. 


Soda. 


Lime. 


Mag- 
nesia. 


Iron 
Oxide. 


Phos- 
phoric 
Acid. 


Sul- 
phuric 
Acid. 


Silica. 


Chlo- 
rine. 


Hen's egg: entire, 
white . 
yolk . . 


3-48 
4.61 
2.91 


17-37 

31-41 

9-29 


22.87 

31-57 

5-87 


10.91 

2.78 

13-04 


I. 14 

2.79 
2.13 


0-39 
0.57 
i-6s 


37.62 

4.41 

65.46 


0.32 
2.12 


0.31 
1.06 
0.86 


8.98 

28.82 

1-95 



Egg Shell, according to Konig, has the following composition: 

Calcium carbonate 89 .0-97% 

Magnesium carbonate o .0- 2% 

Calcium and magnesium phosphate o • 5~ 5% 

Organic substances 2 .0- 5% 

Egg Membrane, the skin covering the white, consists chiefly of a 
protein of the keratin group. 

White of Egg is an albuminous fluid without cellular structure. It 
has a specific gravity of 1.038-1.045, contains 12-18% of solids, and is 
always alkaline in reaction. When fresh the alkalinity is slight, but 
during ageing increases markedly, owing to the formation of ammonia. 
Determinations of ammonia are accordingly valuable in detecting deteri- 
oration. A blue color forms in the portion of the white adjacent to the 
yolk on boiling; this is due to iron sulphide formed by the action of hydro- 
gen sulphide, liberated from the white, on iron of the yolk. The well- 
known blackening of silver by eggs is due to silver sulphide formed in a 
similar manner. 

The average composition of the white of hens' eggs is as follows: 

Water 86.2% 

Fat, lecithin, cholesterol, etc traces 

Protein 12.7% 

Dextrose o-5% 

Ash 0.6% 

100 .0% 

Fats, Lecithin, and Cholesterol are present only in negligible quantities. 



270 FOOD INSPECTION AND ANALYSIS. 

Proteins. — According to Osborne and Campbell * the proteins of 
the white of egg are four in number: ovalbumin, conalbumin, ovomucin, 
and ovomucoid. No sharp and distinct separation of these bodies has 
yet been made. 

Ovalbumin is a crystallizable protein and forms with conalbumin the 
largest portion of the protein of the egg white. In a 2.5% solution in 
water, the ovalbumin starts to coagulate at 60° and yields a dense coagulum 
at 64°. Stronger solutions require a somewhat higher temperature for 
coagulation. 

Conalbumin bears a close resemblance to ovalbumin, but is not crys- 
talline, coagulates at a lower temperature (below 60°), and the coagulum 
is more flocculent. 

Ovomucin is a globulin-like substance, precipitated from egg white 
by dilution with water. When dried and washed with alcohol it is a light, 
white powder soluble in strong sodium chloride solution. Some authors 
consider it as a part of " ovoglobulin " which is precipitated completely 
by saturation with magnesium sulphate, or half saturation with ammonium 
sulphate. 

Ovomucoid is not coagulable by heat and may be separated (imperfectly) 
from the filtrate from the coagulable proteins. It is precipitated by alco- 
hol and saturation with ammonium sulphate, but not by half saturation 
or by any proportion of sodium chloride, sodium sulphate, or magnesium 
sulphate. 

Carbohydrates. — Kojo f reports 0.55% and Morner | 0.3-0.5% of 
dextrose. Diamare § suggests that the sugar is not present as such, 
at least at the outstart, but is formed by the action of an amylolytic enzyme. 

Ash is present to the extent of 0.04-0.07% and consists, as shown 
by the analyses on page 269, chiefly of alkali chlorides. 

Egg Yolk. — This contains over 50% of solids or about four times that 
of the white and is also much more complex in composition. In addition 
to proteins it contains large amounts of fat, lecithin, and other phospho- 
lipins, also glucolipins, cholesterol, lutein (a lipochrome), hematogen 
(a nuclein ?), salts, and other constituents. 

Because of the complex composition of egg yolk which is as yet im- 



* Jour. Amer. Chem. Soc, 22, iqcxj, p. 422. 
t Zeits. physiol. Chem , 75, 191 1, p. i. 
X Ibid., 80, p. 430. 
§ Chem. Zentbl., i, 1910, p. 1732. 



EGGS. 271 

perfectly understood, an accurate statement of composition is impossible. 
The following is based on the data at present available: 

Water 49 . 5 % 

Fat 18.0% 

Lecithin and other phospholipins 11 .0% 

Protein (ovovitellin, etc.) 14 -5% 

Dextrose o-3% 

Lutein, cholesterol, hematogen, cerasin (?), etc. . . . 5.7% 

Ash 1.0% 

100.0% 

The Fat of egg yolk, extracted in various v^^ays, has been studied by 
several investigators, but their results are far from comparable. 

Pennington * first dried the yolk by extraction for 2 days with abso- 
lute alcohol, evaporated the extract to dryness, and added the residue 
to the portion insoluble in the alcohol; she then ground the mass and 
extracted the fat for 2 days with petroleum ether (b. pt. 60° C). Spaeth f 
and also Kitt,{ secured the fat by extracting the dried egg yolk with ether, 
while Palladino and Toso § expressed it from the yolk after boiling. 

The constants of the fat obtained by the authors named, also Serono 
and Palazzi,|| follow: 



Analysts. 


> . 

cao • 

eg- 




> "> 

Pi 


a 




.s 
si 



t-H 



l| 

ca 


'S . 


< 


u 

C 3 

■Sz; 


u 

<L> 

E 

3 

!H 
'0 
< 




Serono and Palazzi. 

Pennington 

Spaeth 

Kitt 

Paladino and Toso . 


9121 

o!88i* 
0.9144 
0.91S6I: 


1.4627 
1.4713 


9° 


23° 


82.3 
62.8 

68. 5t 

72.1 

81.4 


198.9 
179.9 
184.4 
190.2 
185.8 


0V7 
0.4 


3.82 


76^1 
95.2 


206 
195 


37° 
36° 
35° 



* At 100.° t Of fatty acids 72.6. 



X At 20°. 



Lecithin (C42H84NPO9) is a characteristic constituent of egg yolk 
especially useful in detecting the presence and approximate amount of 
eggs in alimentary paste. 



* Jour. Biol. Chem., 7, 1910, p. 109. 

t Zeits. Nahr. Unters. Hyg., 10, 1896, p. 171. 

X Chem. Ztg., 21, 1897, p. 303. 

§ Gior. pharm. chim.; abs. Jour, pharm. chim., 6, i{ 

II Arch. farm, sper., 11, p. 553. 



), p. 247. 



272 FOOD INSPECTION AND ANALYSIS. 

Lutein (C40H56O2), the chief coloring matter of egg yolk, has the 
same empirical formula as xanthophyl and carotin, but has a lower melting 
point than xanthophyl and is more soluble in alcohol than carotin. 

Cholesterol (C27H44O) is present, according to Berg and Angerhaucen,* 
in amounts equivalent to about 1.40% in hens' and duck eggs. 

Ovovitellin, the characteristic phosphoprotein of eggs, has been studied 
by Osborne and Campbell, who believe the substance as ordinarily isolated 
to be a mixture of compounds of true vitellin and lecithin. 

Hematogen has been isolated by Bunge,t who believes it to be the 
mother substance of hemaglobin. It is similar to the nucleins and con- 
tains sulphur, phosphorus, and iron. 

Sugar. — A small amount of dextrose is present in egg yolk. 

Grades of Eggs. — Various systems of sorting are in vogue in dif- 
ferent regions, but the following classification appears to be most common : 

1. Extras. — Eggs of good size and uniform color, free from all defects. 

2. Firsts. — Same as extras, but not of uniform color. 

3. Seconds. — Small, dirty, checked, " weak " (with thin whites), 
and " leaker " eggs. 

4. " 5/>o/5." — showing on candling dark areas due to mold or de- 
veloping embryo (" blood rings "). 

5. " Rots." — Opaque on candling and offensive in odor on opening. 

In addition the following are distinguished: Green Eggs with a green- 
ish color in the white. Musty Eggs with a characteristic disagreeable taste, 
and Sour Eggs, with a sour taste. 

Preservation of Eggs. — Owing to the porous nature of the shell, the 
moisture of the contents gradually grows less by evaporation, and the egg 
loses in weight. Air also passes in through the shell pores, carrying 
various microbes, which result in ultimate decomposition and spoiling 
of the egg. Nature has provided the shell with a thin surface coating of 
mucilaginous matter, which, however, is easily washed off. This coating 
tends to partially close the pores, and for best results in keeping should 
not be removed by washing. 

Eggs are commonly preserved by protecting them as far as possible 
from the air. This is accomplished in a variety of ways, the most common 
being to pack the eggs in salt or bran, so that the packing medium fills 
up the interstices between the eggs. Eggs thus packed will keep con- 
siderably longer than when exposed to the air. A solution of salt is some- 

* Zeits. Unters. Nahr. Genussm., 29, 1915, p. 9. 
t Jour. Chem. Soc, 93-94, p. 1500. 



EGGS. 273 

times employed, and also lime water, the eggs being simply packed in 
the solution. The use of lime water is, however, open to the serious objec- 
tion that a disagreeable odor and taste are imparted to the eggs. 

Eggs are sometimes coated with gelatin, vaseline, wax, or gum, so as 
to cover them with an impervious layer, either by dipping them in the coat- 
ing medium, or by varnishing or otherwise applying the substance to the 
egg shell. By far the most efficacious egg coating has been shown by 
experiments in the North Dakota Experiment Station,* and also in Ger- 
many, to be sodium and potassium silicate, or water glass. The fresh 
eggs, preferably unwashed, are packed in a jar, and a solution of water 
glass (i part of syrupy water glass to 9 parts of boiled water) is poured 
over them. According to the North Dakota experiments, at the end 
of three and a half months, eggs packed in this manner the first of August 
appeared to be perfectly fresh. 

One drawback to this method is that eggs so treated break more easily 
on boiling, but this may be prevented by carefully piercing the shell with 
a strong needle. 

Cadet de Vanx has proposed immersing the egg in boiling water for 
twenty seconds, the result being that a very thin layer of the egg-white 
next the shell becomes coagulated, thus forming an impervious coating 
inside the shell. 

Cold-storage Eggs. — The preservation of eggs by storage at low tem- 
peratures has become an enormous industry. The temperature employed 
differs somewhat, but a little below the freezing-point of water ( — 1° to 
— 2° C.) gives the best results. The length of storage varies usually from 
one to ten months. 

Experiments conducted by Wiley,t under authorization from Con- 
gress, brought out certain points as to the physical and chemical changes 
found to take place during cold storage. After breaking the shell and 
keeping atroom temperature one day, the odor of eggs stored for 3.5 months 
was different from that of fresh eggs, but was not disagreeable. This 
odor increased on longer storage, and after 12.6 months became very 
characteristic. After 16.6 months, a musty odor was noticed immediately 
after opening the egg. 

Chemical analysis by Cook showed that eggs in storage for one year 
lost 10% of the total weight, due to evaporation of water from the whites. 

* Farmer's Bui. 103, U. S. Dept. of Agric, p. 18. 
t U. S. Dept. of Agric, 'Bur. of Chem., Bui. 115. 



274 FOOD INSPECTION AND ANALYSIS. 

Storage also caused a lowering of the amount of coagulable protein and 
of lecithin phosphorus, but an increase in lower nitrogen bodies, pro- 
teoses, and peptones. The acid reaction of yolks diminished during 
storage. 

Microscopical examination by Howard and Read brought to light 
occasional rosette crystals in the yolk of eggs stored for 12 months or 
longer, but the nature of these crystals and their diagnostic value do not 
appear to have been established. 

Spoilage of Eggs. — Pennington * and her co-workers have found an 
average of 2 and 6 organisms per gram respectively in the white and yolk 
of strictly iresh eggs when incubated at 37° C, and 7 and 9 organisms 
per gram when incubated at 20° C. The average percentage of ammo- 
niacal nitrogen in the whole egg was 0.0013. Resistance to spoilage 
appears to be greatest in the Spring when the moisture content is least 
and least in August and September when the moisture content is greatest. 
On keeping both the bacterial count and the per cent of ammoniacal 
nitrogen increase, but the latter to a much lesser degree than the former. 
The authors state that for certain constituents at least the count must 
approach ioc,coo,ooo per gram before chemical methods for the detection 
of bacterial activity are of value. 

Seconds, including medium stale, hatch spots, heavy rollers, dirties, 
checks, and eggs with yolks partially mixed with the white, opened 
aseptically, contained less than 1000 organisms per gram, while 26.5% of 
eggs with adhering yolks, 50% with dead embryos, 75.9% of moldy 
eggs, 66.7% of white rots, and 100% of black rots contained over loco per 
gram. With the exception of rots few contained B. coli. 

Firsts opened commercially in July had low counts and the same 
was true of most clean-shelled seconds, only 8.3% containing over 1,000,000 
organisms per gram, while 16.6% of the dirties, 18.8% of the checks, and 
20% of the eggs with yolk partially mixed with the white exceeded that 
limit. B. coli ranged up to ico,coo per gram being no greater in the last 
named grades than in clean-shelled seconds. Market seconds in the 
producing sections during Summer averaged 0.0017-0.0022% of ammo- 
niacal nitrogen, while other grades better than white rots varied up to 
0.0030% or more. 

Houghton and Weber f obtained the following percentages of am- 
moniacal nitrogen calculated to the dry substance of the liquid egg: 

* U. S. Dept. of Agric, Bui. 51, 1914 and 224, 1916. Bur. of Chem. Circ, 98, 1912. 
t Biochem. Bui. 3, 1914, 447. 



EGGS. 275 

Folin Folin 

Titration Nesslerization 

Method. Method. 

Seconds 0.0114% 0.0124% 

Spots 0.0141% 0.0200% 

Light rots 0.0173% 0-0215% 

Rots o .0262% o .0299% 

Black rots o . 1696% o . 1486% 

The authors also found Klein's modification of the Van Slyke method 
useful in detecting blood rings, spots and light rots, and the acidity of 
the fat in detecting spots and lower grades, 

FROZEN EGGS. 

In the handling of eggs many become cracked or otherwise injured 
to an extent which renders them unfit for transportation. These are 
either sold to bakers for immediate use, or else opened and kept from 
spoiling by freezing, or drying. The portions of " spot eggs " that do 
not show evidence of damage are also treated by one of these methods, 
but together with white rots are now legitimately sold only for tanning 
certain kinds of leather. 

Pennington and co-workers found that frozen eggs having less than 
5,000,000 bacteria and less than 100,000 B. coli per gram, and with less 
than 0.0024% of ammoniacal nitrogen on the wet basis (0.0087% dry basis) 
can be made from most of the regular breaking stock. 

The preservatives formerly much employed in opened eggs are boric 
acid and formaldehyde. The latter is especially effective as an egg pre- 
servative. If a small quantity be added and stirred into opened eggs 
that have become absolutely putrid, the result is astonishing. The 
product is completely deodorized, and exhibits the outward appearance 
at least of fresh eggs. 

Formaldehyde, if present, may readily be detected by heating some 
of the egg directly with the hydrochloric-acid ferric-chloride reagent used 
in testing milk for formaldehyde, carrying out the process exactly as in 
the case of milk. 



276 FOOD INSPECTION AND ANALYSIS. 



DESICCATED EGGS. 

This product is placed on the market as a coarse orange-yellow powder. 
It is particularly valuable because of its concentrated form and excellent 
keeping qualities without storing at freezing temperatures. 

Preparation of Desiccated Eggs. — Breaking stock suitable for freezing 
may be preserved by drying, using the same precautions as to cleanliness 
in opening and handling. 

Bailey * who is located in one of the principal breaking sections 
(Kansas) states that the drying is carried out by spreading over cylinders 
or belts which move in a current of warm air or by heating in a vacuum. 
In some processes the drying is finished in wire baskets. The temper- 
ature is kept below 120° F. (49° C.) to prevent coagulation of the albumin. 
Salt or sugar are sometimes added to aid in preservation. 

If properly prepared the powder mixes readily with water, assuming 
much the same form as before drying. 

Composition.— The following are analyses of two samples one (A) 
made by the Bureau of Chemistry, the other (B) by the Massachusetts 
State Board of Health : 

A. B. 

Water 6.80 5.95 

Protein (NX 6.25) 45-20 48.15 

Protein by difference 5 1 - 20 

Fat 38.5 40.56 

Ash 3.5 5.34 

Inspection. — Pennington states that the percentage of ammoniacal 
nitrogen is not a reliable index of the quality of the stock, owing to the 
volatilization of more or less of this constituent during desiccation. As 
in the case of frozen eggs, factory inspection is desirable, particularly as 
the drying is not carried out at a sterilizing temperature. f 

ANALYSIS OF EGGS. 

Physical Examination of Eggs. — Various physical tests, based on 
the gradual increase in size of the air chamber (Fig. 60), have been pre- 
scribed for ascertaining the approximate age of an egg. Thus, accord- 

* Source, Chemistry, and Use of Food Products, Phila., 1914, p. 438. 
t See Maurer, Kan. Agric. Exp. Sta., Bui. 180, p. 345. 



EGGS. 277 

ing to Delarne, if the egg, when placed in a io% salt solution sinks to 
the bottom, it may be considered perfectly fresh; if it remains immersed 
in the liquid, it is to be considered at least three days old; and if it rises 
to the surface and floats thereon it is more than five days old. This test 
is a very rough one, and is useful only for eggs that have been kept in 
the air. Preserved eggs cannot be gauged by this means. 

The commercial method of examining eggs is by " candling," con- 
sisting in placing the egg in front of an opening in a screen between a bright 
light and the eye. If the egg is fresh, it will show a uniform rose-colored 
tint, without dark spots, the air-chamber being small and occupying 
about one-twentieth the capacity of the egg. If the egg is not fresh, it 
will appear more or less cloudy, being darker as the egg grows older, be- 
coming in extreme cases opaque. At the same time the air-chamber 
grows larger as the age increases. So-called " spots " show on candling 
black patches. 

Greenlee * has proposed the moisture content as an index of age and 
has devised a " rate formula " for predicting the condition after holding 
for a definite time at a definite temperature. 

Preparation of the Sample.!— The egg is first weighed as a whole and 
afterwards boiled hard, cooled, and again weighed. The shell, white, and 
yolk are then carefully separated and each weighed. After rejecting the 
shell, the yolk and white are separately reduced by a chopping-knife to 
the size of wheat grains. These portions ar^ dried partially at a tem- 
perature not exceeding 45° C, weighed, and afterwards ground to a fine 
powder in a mortar. 

Pennington separates the yolk from the white by draining on a piece 
of wire gauze, then washes off any adhering white with water and dries 
by extraction with alcohol as described on page 271. 

Fat constants are determined on the petroleum ether extract. 

Determination of Water, Ether Extract, Total Nitrogen, and Ash 
are made in practically the same manner as with flesh foods. It is well 
to determine water with the addition of sand, after which the residue 
may be ground up for extraction with ether, using a continuous flow ex- 
tractor. 

Little attention has been paid as yet to the complete separation and 
determination of the nitrogen compounds in the white and yolk, and it 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 83, 191 1. 
t Woods and Merrill, Maine Exp. Sta^^ Bui. Ti. p. 92. 



278 FOOD INSPECTION AND ANALYSIS. 

is customary to calculate the protein by the use of the factor 6,25 or by 
difference. 

Determination of Lecithin. — The Juckenack Method (page 366), de- 
vised for noodles, is also applicable to eggs, previously dried at a moderate 
temperature with sand, and to commercial dried eggs. If desired, the 
free lecithin, or that present in the ether extract, and the combined lecithin, 
obtained by extraction w^ith absolute alcohol of the residue after removal 
of the ether extract, may be separately determined. 

Detection of Preservatives. — Formaldehyde may be readily detected by 
heating directly with the acid ferric chloride reagent as described for milk. 

Boric Acid. See Chapter XVIII. Bertrand and Agulhon * find by 
their spectroscopic method o.i 16-0. 136 mg. of boron as hydroxide per 
kilo of egg white and o.co8 mg. per kilo of egg yolk, to which no pre- 
servative has been added. These amounts are not detectable by ordinary 
methods. 

Salicylic Acid. — Froideaux f proceeds as follows: Mix 25 grams of 
desiccated or 30 grams of liquid egg with 250 cc. of water, stir in 125 
cc. of 8% sodium hydroxide solution, and warm for 45 minutes on a 
water-bath. Break up the mass with a rod and filter. Acidulate the 
filtrate with hydrochloric acid, precipitate proteins with sodium phospho- 
molybdate, filter, extract the filtrate with ether, and proceed as usual. 

EGG SUBSTITUTES. 

There have been many preparations in powdered form sold under 
this name, nearly all claiming to contain all the ingredients of eggs, but 
most of them falling far short of these claims. Some of them, as, for 
instance, those made from desiccated skimmed milk, do contain nitro- 
genous matter, but as a rule little, if any, fat. 

Two samples of "egg substitute" sold in Massachusetts were anal- 
yzed with the following results :t 

A. B. 

Protein 16.94 18.72 

Fat 3.43 3.40 

Water 6.71 7.01 

Corn starch, salts, and coloring matter. 72.92 70.87 



* Compt. rend., 1913, 156, p. 2027. 

t Jour, pharm. chim., 10, p. 18. 

X An. Rep. Mass. State Board of Health, 1895, p. 675. 



EGGS. 



279 



A ten-cent package of sample A, weighing about 2 ounces, was alleged 
to be equivalent to 12 eggs. Starch furnished the chief ingredient in 
both samples. 

One of the most flagrant examples of fraud in this connection was a 
product sold under the name " N'egg," advertised to contain the nutritive 
equivalent of the whites and yolks of a dozen eggs, " their composition 
being based on careful scientific analysis of natural eggs." It was put 
up in two small boxes, one containing a white and the other a yellow 
dry powder. Both were entirely devoid of nitrogen, and consisted of 
nearly pure tapioca starch with a little common salt, the color of the 
"yolk" being due to Victoria yellow. 

Some egg substitutes are sold under the name of " custard powders," 
and are alleged to take the place of eggs in cooking. These are variously 
made up of mixtures of skim-milk powder, coloring m.atter, and baking 
powder ingredients as shown from the following analyses : * 

CUSTARD POWDERS. 



Starch 

Albuminous compounds 

Soluble coloring matter 

Baking soda 

Tartaric acid 

Phosphates 

Carbonates of lime and magnesia . 

Water 

Ash 



86 25 

o 59 
0.88 



11.83 

0.45 



^•45 
'58 



13.69 
0.38 



51 03 
6.01 

15 33 

13.69 

o. 24 

2.70 

II 00 



26.38 
2.96 

50.70 
10.33 



9 63 



52.32 
6.00 

22. II 
"■37 



8.20 



53 82 
5.06 

26.71 
6.19 



8.22 



Food and Sanitation, Nov. 25, 1893. 



CHAPTER X. 
CEREALS AND THEIR PRODUCTS, VEGETABLES, FRUITS, AND NUTS. 

The chief points of difference in composition between the animal 
foods already treated of, and those of the vegetable kingdom, are apparent 
in the relative amounts of proteins and carbohydrates. The proteins 
present in the cereals differ materially both in character and amount from 
those in the flesh foods, being, as a rule, present in much smaller amount. 
The leguminous foods, such as peas, beans, and lentils, and nuts as a rule, 
are, however, comparatively high in nitrogenous content. 

The carbohydrates, which in the flesh foods are almost entirely lack- 
ing, and in milk in the form of lactose make up about one-third of the 
solid matter, constitute the greater part of the cereals and legumes, being 
present chiefly in the form of starch. 

In nuts, with few exceptions such as the chestnut and peanut, starch 
is absent. 

The composition of the principal cereal grains is tabulated as follows 
by Villier and ColHn: 



Wheat. 


Barley. 


Rye. 


Oats. 


Rice. 


Com. 


Millet. 


13-65 


13-77 


15.06 


12.37 


13. II 


13.12 


11.66 


12.35 


II. 14 


11.52 


10.41 


7-«5 


9-85 


9-25 


1-75 


2.16 


1-79 


5-32 


0.88 


4.62 


3-50 


1-45 


1.56 


0-95 


1. 91 


' 


2.46 


1 


2.38 


1.70 


4.86 


1-79 


I 16.52 


3-3« 


65-95 


64.08 


61.67 


62.00 


54.08 




62.57 


J 


2-53 


5-31 


2.01 


II. 19 


0.63 


2.49 


7.29 


1. 81 


2.69 


1. 81 


3.02 


1. 01 


1-51 


2-35 



Buck- 
wheat. 



Water 

Nitrogenous substances 

Fat 

Sugar 

Gum and dextrin 

Starch 

Cellulose 

Ash 



12.93 

10.30 

2.81 



55-81 

16.43 
2.72 



The following results of the analyses of cereal grains are summarized 
from the work of the Division of Chemistry, United States Department 
of Agriculture : * 

* Bulletin 13, part 9. 
280 



d 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 
CEREAL GRAINS. 



281 



Barley: 

Mean 

Buckwheat: 
Mean 

Corn, domestic: 

Maximum 

Minimum 

Mean 

Oats, domestic : 

Maximum . 

Minimum . 

Mean 

Rice: 

Unhulled 

Unpolished . . . 
Polished* 

Rye, domestic : 

Maximum 

Minimum 

Mean 

Wheat, domestic: 

Maximum , 

Minimum. 

Mean 

Wheat, foreign: 

Maximum 

Minimum. ... 
Mean 



Num- 
ber of 
Analy- 
ses. 



14 



Weight 
of 100 
Ker- 
nels, 
Grams. 



Moist- 



4 
6 

14 



-533 
.069 

.312 
.608: 

-979: 



2.038: 
2.918, 

2.929 
2.466 
2.132 



Pro- 
teins. 



4- 



201 
932 
493 



).i9o 

!-I25| 

5.866 

;-723 

— 250] 

1-076, 



6.47 

12.31 

12.32 

9-58 

10.93 

13.02 

7.87 

10.06 



12.34 

11-45 

9-54 

10.62 

14-53 

7. II 

10.62 

12.97 

8.52 

11.47 



11.52 
10.86 

11-55 
8.58 
9.88 

15-05 

9.10 

12.15 

7-95 
8.02 
7.1! 

18.99 

8.40 

12.43 

17-15 

8.58 

12.23 

14-52 

8.58 

12.08 



Ether 
Ex- 
tract. 



Crude 
Fiber. 



Ash. 



2.67 

2.06 

5.06 
2.94 
4.17 

6.14 
0-93 
4-33 

1.65 
1.96 
0.26 



2-30 
1. 16 
1-65 



2.50 
0.28 
1-77 

2.26 

0.73 
1.78 



3.81 
10.57 

2.00 
1 .00 
1. 71 

16.65 

8-57 
12.07 

10.42 

0-93 
0.40 

2.50 
1.65 
2.09 

3-72 
1.70 

2-36 



1.87 
2.28 



2.87 

1-85 

1-55 
1. 19 
1.36 

4-37 
2.47 

3-46 

4.09 

1-15 
0.46 

2.41 
1. 71 
1.92 

2-35 
1.40 
1-82 

2- 04 
1.67 

1-73 



5fl fe 

■a S"^ 



Wet 
Gluten. 



72.66 

63-34 

75-07 
68.97 

71-95 

61.44 
53-70 
58.75 

65 - 60 
76.05 
79.36 

75.36 
63-61 

71-37 

76.05 39.05 
66.67 12.33 
71.18 26.46 



Dry 
Gluten. 



76.14 
67.01 
70.66 



32-57 
18.72 

25-36 



14.65 

4-70 

10.31 

12.33 
7.00 
9.82 



* Polished rice in the United States is commonly coated with gluccse and talc, ostensibly as a pro- 
tection against dust and the ravages of insects. Such coating is alowed if declared on the label and 
directions for its removal are also given. 

Balland f gives the following percentage composition of beans, lentils, 
and peas: 





Beans. 


Lentils. 


Peas. 




Min. 


Max. 


Min. 


Max. 


Min. 


Max. 


Water. , 


10.10 

13.81 

0.98 

52-91 
2.46 
2.38 


20.40 

25.46 

2.46 

60.98 

4.62 

4.20 


11.70 

20.42 

0-58 

56.07 

2.96 

1-99 


13-50 
24.24 

1-45 
62.45 

3-56 
2.66 


10.60 

18.88 

1.22 

56.21 

2.90 

2.26 


14.20 

22.48 

1.40 

61.10 

5-52 

3-50 


Nitrogenous substances 

Fat 


Sugars and starches. 

Cellulose 


Ash 





f Jour. Pharm. Chem., 1897, pp. 196, 197. 



282 FOOD INSPECTION AND ANALYSIS. 

The composition of potatoes, according to Balland,* is as follows: 





Water. 


Nitroge- 
nous 
Sub- 
stances. 


Fat. 


Sugar 
and 
Starch. 


Cellulose. 


Ash 


Normal state — minimum . . 

maximum. . 

Dried — minimum . . 


66. 1 o 
80.60 


1-43 
2.81 

5-98- 
13-24 


0.04 
0.14 
0.18 
0.56 


15-58 
29.85 
80.28 
89.78 


0-37 
0.68 
1.40 
3.06 


0.44 
1. 18 
1.66 


maximum. . 




4.38 







The composition of the common vegetables, fruits, and berries is thus 
given by Atwater and Bryant.f 



VEGETABLES. 



Asparagus — 
Beans, dried — • 
BeanSjfresh Lima 

Beets, fresh — 

Cabbage — 

Carrot, fresh — 

Celery — 

Cauliflower — 
Cucumber — 

Lettuce — 

Mushrooms — 
Onion, fresh — 

Parsnip — 

Pumpkin — 

Radish — 

Rhubarb — 

Squash — 

Tomato, fresh — 
Turnip — 



as purchased. . . 
as purchased. . . 
-edible portion . . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible portion . . 
as purchased. . . 
edible portion. . 

as purchased 

edible portion . . 

as purchased 

as purchased. . . 
edible portion. . 
as purchased . . . 
edible portion . . 
as purchased. . . 

as purchased 

edible portion. . 

as purchased 

edible portion. . 
as purchased. . . 
edible portion . . 

as purchased 

edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
as purchased. . . 
edible portion. . 
as purchased 



12; 



24 



II 

15 



10 



27 
19 



55-0 



15-0 



20.0 
20.0 



15-0 
15-0 



10. o 
20.0 



50.0 
30.0 



40.0 
50.0 



30.0 



94 



22. 5 

7-1 
3-2 
1.6 

1-3 
1.6 

1-4 



3-5 
1.6 

1-4 
1.6 

1-3 
i.o 

-5 

1-3 

-9 

.6 

-4 
1-4 

-7 

-9 
1-3 

-9 



03 >> 



.2 
.8 


3- 
59- 


-7 


22. 


•3 


9- 


.1 


9- 


.1 


7- 


-3 


5- 


.2 


4- 


.4 


9- 


.2 


7- 


.1 


3- 


.1 


2- 


•5 


4- 


.2 


3- 


.2 


2. 


-3 


2. 


.2 


2. 


-4 


6. 


-3 
-3 


9- 

8. 


-5 


13- 


-4 


10. 


.1 


5- 


.1 


2. 


-3 


8. 


.1 


5- 


-7 


3- 


-4 


2. 


-5 


9- 


.2 


4- 


.4 
.2 


3- 
8. 


.1 


5- 



4-4 

1-7 

.8 

-9 
I.I 
I.I 



2-5 



1.2 



-7 

-7 

i-i 



.6 
1-3 



* Jour. Pharm. Chem., 1897, pp. 298-300. 

t Bui. 28, Office of Exp. Station U. S. Dept. of Agriculture. 



c3 C (D 

_ o 
ty <u o3 

3 au 



105 
1605 

570 
255 
215 
170 

145 
125 
210 
ifo 

85 
70 
140 
80 
70 
90 

75 
210 
225 
205 
300 
240 
120 

60 
135 

95 
105 

65 
215 
105 
105 
185 
125 



4 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



283 



FRUITS. 



Apples — 

Apricots — 

Bananas — 

Blackberries — 
Cherries — 

Cranberries — 
Currants — 
Figs, fresh — 
Grapes — 

Huckleberries - 
Lemons — 

Muskmelons — 

Oranges — ■ 

Pears — 

Pineapple — 
Plums — • 

Prunes — 

Raspberries — 
Strawberries — 

Watermelon — 



edible portion , 
as purchased. . , 
edible portion. . 
as purchased. . . 
edible portion. . 
as purchased. . . 
as purchased. . 
edible portion . . 

as purchased 

as purchased. . . 
as purchased. . , 
as purchased. . , 
edible portion. . 
as purchas -d. . . 
-edible portion . . 
edible portion. , 
as purchased. . . 
edible portion. , 
as purchased. . , 
edible portion . , 
as pui chased. . . 
edible portion. . 
as purchased. . 
edible portion. . 
edible portion., 
as purchased. .. 
edible portion. , 
as purchased. . , 
as purchased. ., 
edible portion., 
as purchased . . 
edible portion. , 
as purchased. .. 



o g 

45 



29 



23 



3 

24 

I 






84. 


25.0; 63. 


: 85- 


6.0 7Q. 





7.S- 


35-0 


48. 




85. 




80. 


5-0 


76. 




88. 




85- 




79- 





77- 


25.0 


58. 




81. 




89. 


30.0 


62. 




89. 


50.0 


44- 




86. 


27.0 


63- 




84. 


10. 


76. 




89. 




78. 


5-0 


74- 




79- 


5.« 


75- 




85- 




90. 


5-0 


85- 




92. 


59-4 


37- 



PL. 



-4 

•3 

1. 1 

i.o 

1-3 
.8 

1-3 
1.0 

-9 
-4 
1-5 
1-5 
1-3 
1.0 
.6 
1.0 

-7 
.6 



.6 
.6 
•5 
-4 
1.0 

.9 
■9 
-7 
1.0 
1.0 
-9 
•4 
.2 






5 
3 

6 

4 
o 
8 
8 
6 

6 

2 
6 

7 

5 

2 
I 

5 
4 
3 

6 
6 

2 

I 



14- 
10. 

13- 
12. 
22. 
14. 
10. 
16. 
15- 
9- 
12.8 



•4 
,6 

•5 
9 
3 

.6 
II. 6 

8-5 
14. 1 
12.7 

7 
. I 
.1 
■9 
■4' 
.6 

.4! 
,0 



1.6 



2-5 



1-5 



4-3 



2-7 



■4 



2t) 

C3 3 0) 

"s 0.0 



290 
220 
270 

255 

460 

300 

270 

365 

345 
215 
265 
380 
450 
335 
345 
205 

145 
185 
90 
240 
170 

295 
260 
200 
395 
370 
370 
335 
255 
180 

17s 

140 

60 



The following analyses of apples made by Browne * are of interest. 
The first four analyses show the changes that occur in the composition 
of a Baldwin apple at different stages of its growth. Below these is 
given the average of the analysis of 160 samples, representing 27 varieties 
of apples. 

COMPOSITION OF A BALDWIN APPLE AT DIFFERENT PERIODS, 



Condition. Water. 

1 


Solids. 


Invert 
Sugar. 


1 

Su- 1 Total 
crose. 1 Sugir. 


Total 
Sugar 
after In- 
version. 


Starch. 


Free 

Malic 
Acid. 


Ash. 


Sugar 
Co- 
efficient. 


Very green.,. 81.53 

Green 79-8i 

Ripe 80.36 

Over-ripe. ..' 80.30 


18.47 
20.19 
19.64 
19.70 


6.40 
6.46 

7.70 
8.81 


1.63 

4-05 
6.81 
5.26 


8.03 
10.51 

14-51 
14.07 


8. II 
10.72 
14-87 
14-35 


4.14 

3-67 
0.17 


1. 14 

0.65 
0.48 


0.27 

0.27 
0.28 


47.16 

53-10 

75-71 
72.84 



* Penn. Dept. of Agriculture, Bulletin 58. 



284 



FOOD INSPECTION AND ANALYSIS. 



AVERAGE COMPOSITION OF 27 VARIETIES OF APPLES. 

Water 83.57 

Solids 16.43 

Invert sugar 7 -92 

Sucrose 3 .99 

Total sugar 11 .91 

Total sugar after inversion 12.12 

Free malic acid 0.61 

Ash 0.27 

Sugar coefficient 73-76 

The composition of the commoner nuts as compiled by Atwater and 
Bryant* is shown in the following table; 



NUTS. 






Pi 






Almonds — 

Beechnuts — 

Brazil-nuts — 

Butternuts — 

Chestnuts, fresh — 

Cocoanuts — 

Filberts — 

Hickory-nuts — 

Peanuts — 

Pecans — 

Pistachios — 
Walnuts, Calif'nia- 



edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased . . 
edible portion, 
as purchased. . 
edible portion, 
as purchased. , 
edible portion, 
as purchased. . 
edible portion, 
as purchased. . 
edible portion, 
as purchased, 
edible portion 
as purchased, 
edible portion 
—edible portion 
as purchased. 



45-0 
40.8 

49-6 
86.4 
16.0 
48.8 
52.1 
62.2 
24-5 
53-2 



73-1 



4-8 
2-7 

4.0 
2-3 
5-3 
2.6 

4-4 
.6 

45-0 

37-8 

14. 1 

7-2 

3-7 

1.8 

3-7 
1-4 
9.2 
6.9 

3-0 
1-4 
4.2 

2-5 

-7 



20.0 

11-5 
21.9 

13-0 

17.0 

8.6 

27.9 

3-8 
6.2 

5-2 

5-7 

2.9 

15.6 

7-5 
15-4 

5-8 
25-8 
19-5 

II. c 

5-2 
22.3 

18.4 
4.9 



17-3 

9-5 

13.2 

7.8 

7.0 

3-5 

3 5 

-5 

42.1 

35-4 
27-9 
14-3 
13.0 
6.2 
II. 4 

4-3 
24.4 

18.5 
13-3 

6.2 
16.3 
13.0 

3-5 



1.8 



2-5 



1.4 



2.0 
I.I 

3-5 
2.1 

3-9 
2.0 
2.9 
-4 
1-3 
I.I 

1-7 

-9 
2.4 
I.I 
2.1 

.8 
2.0 
1-5 
1-5 

-7 
3-2 
1-7 

-5 



3030 
1660 

3075 
1820 
3265 

1655 
3165 

430 
1125 

945 
2760 

1413 
3290 

1575 
3345 
1265 
2560 
1935 
3455 
1620 

2995 
3306 



'■ U. S. Dept. of Agric, Off. of Exp. Station, Bui. 28. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



285 



GENERAL METHODS OF ANALYSIS. 

Preparation of the Sample. — Except otherwise stated grind%o as to 

pass a. sieve with round holes i mm. (^ inch) in diameter using a hand 
mill, iron mortar, or other suitable device. 

The following methods for water (standard method), ash, protein, 
fiber, fat, and nitrogen-free extract, in essential details, have been in use 
since the middle of the nineteenth century and have been adopted by the 
A. O. A. C. 

Determination of Water. — Standard Method. — Dry 2 grams of the 
material to constant weight (about four hours) at the temperature of 
boiling water, in a current of dry hydrogen or in vacuo. The apparatus 
described on page 50 may be used. 

Determination of Moisture in Grain, Legumes, Oil Seeds, etc. — 
Brown and Diwel Method.* — This method is especially useful in guarding 

against an excessive amount of 
moisture in grain, which not only 
adds weight but also causes deterio- 
ration through the growth of bac- 
teria and moulds. 

The apparatus (Fig. 61) consists 
of a condenser- tank (^4) and an 
evaporating-chamber (B) with a 
cover (k) and a mica window (m), 
the whole supported on a stand (C). 
It is arranged for conducting six 
distillations at the same time. 

The distilling-flask is shown at 
the left ip') in the wooden rack used 
only during filling and at the right 
(p) in position for distillation. 

Weigh into the distilling-flask 

100 grams (corn, barley, wheat, rye, 

unhulled rice, kafir, flaxseed, soy 

bean) or 50 grams (oats, cottonseed) 

of the whole grain and add 150 cc. 

Fig. 61.— Brown and Duvel Apparatus for ^j hydrocarbon engine oil with a 

Determination of Moisture in Grain. ^ 1 • ^ • f o 

End View flash-pomt m an open cup of 200 - 




' U. S. Dept. of Agric, Bur. of Plant. Ind., Bui. 99, and Circular 72. 



286 FOOD INSPECTION AND ANALYSIS. 

205° C. Close the neck of the flask with a rubber stopper carrying a 
thermometer {q), the bulb of which extends well into the mixture of oil 
and corn; connect the side tube by means of another cork with the 
condenser- tube {s), and heat with the Bunsen burner, so as to bring (in 
twenty minutes) to the proper temperature, which for corn, barley, rice, 
kafir, and cottonseed is 190°, for wheat 180°, for rye and flaxseed 175°, 
for soy bean 170°, and for oats 195° C, When the desired temperature is 
reached turn off the flame, and allow to stand until the moisture ceases to 
drop from the condenser- tube into the graduate {t). The number of cc. in 
the graduate represents the amount of moisture in the grain. 

The results agree closely with those by drying to constant weight in 
a water-oven at 100°. 

After the determination is finished empty the contents of the flask 
on a suitable strainer, thus recovering the oil for further use. 

Ash. — Burn 2 grams of the substance in a platinum dish at the lowest 
possible red heat, as described in Chapter IV. If a white or light- 
gray ash cannot be obtained in this manner, exhaust the charred mass 
with water, collect the insoluble residue on a filter, burn, add this ash 
to the residue from the evaporation of the aqueous extract, and heat the 
whole at low redness until white or nearly so. 

Ether Extract {Fat, etc.). — Extract the residue from the determination 
of moisture for sixteen hours with anhydrous alcohol-free ether in a 
continuous extractor and dry the extract to constant weight in a water- 
oven. The ether extract may also be determined indirectly from the 
difference in weight of the dried substance before and after extraction. 

Protein. — Determine the total nitrogen by the Gunning or Kjeldahl 
method, using i gram of the substance. Calculate the protein by mul- 
tiplying the total nitrogen by the appropriate factor, which varies with 
the different cereals as follows: wheat, 5.70; rye, 5.62; oats, 6.31; corn, 
6.39; and barley, 5.82'. Ordinarily the conventional factor 6.25 is em- 
ployed. 

Crude Fiber. {Cellulose, Lignin, etc.). — Transfer the residue, after 
extraction for the determination of the ether extract, to a 500-cc. Erlen- 
meyer flask, with a mark showing 200 cc, add boiling 1.25% sulphuric 
acid to the mark, heat at once to boiling, and boil gently for thirty 
minutes, shaking cautiously from time to time to prevent the material 
from crawling up on the sides of the flask. Filter through paper, and 
wash once with boiling water. Rinse the substance back into the same 
flask with 200 "cc. of a boiling 1.25% solution of sodium hydroxide, free, 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 287 

or nearly so, from sodium carbonate, boil at once, and continue the boiling 
for thirty minutes in the same manner as directed above for the treat- 
ment with acid. Filter on a tared lilter-paper or Gooch crucible, and 
wash with boiling water till the washings are neutral. Dry at iio° and 
weigh, after which incinerate completely and correct for ash. 

If a tared filter is used, it should be previously dried at iio° for one 
hour in a glass-stoppered weighing bottle, cooled for fifteen minutes 
and weighed. After collecting the fiber on the filter, it is well to wash 
successively with alcohol and ether to facilitate drying. The filter should 
not be pushed down into the weighing bottle until the fiber is dry to the 
touch after which two hours' drying at iio° will be sufficient. A blank 
should be made to ascertain the loss sustained by the filter on treatment 
with alkali and the necessary correction introduced. This error and 
others can be avoided by filtering on a Gooch crucible, but with many 
materials this cannot be used because of clogging. The acid and alkali 
solutions must be exactly 1.25% as determined by titration. 

Nitrogen-free Extract {Starch, Sugar, Gums, e/c.)— Subtract the sum 
of the moisture, ash, ether extract, protein, and crude fiber from 100. 

Detection of Coating of Rice with Talc, Glucose, eic— Glucose is 
detected by copper reduction in a solution obtained by shaking a weighed 
quantity of the rice with water, using for comparison the results obtained 
on uncoated rice by the same method. 

Steatite or Talc is detected by Jones * as follows; 

Shake 5 grams of the unground material successively with 20 cc. of 
ether and several 15-cc. portions of water. Evaporate the ether in a 
platinum dish, add the settlings from the combined aqueous liquids, 
evaporate, ignite, and weigh. 

Detection of Sulphuring m Grain.— Carroll t has shown that the 
following method distinguishes sharply barley, oats and other grains 
in theu- natural condition from those bleached by sulphurous acid. 

Introduce into a 500-cc. flask, provided with a desulphurized perforated 
stopper and a double-bent delivery tube, 10 grams of mossy zinc, a few 
drops of ferric chloride solution, 100 grams of the grain and enough 8% 
hydrochloric acid to cover ^ the grain. Place a loose plug of cotton in the 
neck, attach the stopper, and run the delivery tube into a test-tube con- 
taining 10 cc. of 2% lead acetate solution. If a brownish black pre- 
cipitate of lead sulphide forms, the grain has been sulphured. Particles 

* Chem. News, 108, 1913, p. 176. 

t U. S. Dept. of Agric, Bur. of Plant Tnd.. Circ. 40. 



288 FOOD INSPECTION AND ANALYSIS. 

of dust or zinc, occasionally carried over mechanically, are distinguished 
from lead sulphide by their insolubility in io% ferric chloride solution. 

CARBOHYDRATES OF CEREALS AND VEGETABLES. 

Classification. — As a rule the same carbohydrates are found in all 
cereals, being present, however, in varying proportions. By far the greater 
part of the carbohydrate content of cereals is starch, the other carbo- 
hydrates being comparatively small in amount, so that in rough work 
it is sometimes customary, though incorrect, to assume the entire amount 
of so-called " nitrogen-free extract " or carbohydrates (as determined by 
difference) to be starch. 

The carbohydrates occurring in cereals may be classified as follows : 



Starch 
( Insoluble •! Cellulose 



Principal carbohydrates 
of cereals: 



. Soluble. 



Pentosans 
Sucrose 
Dextrose 
Dextrin 
Raffinose (traces) 



Starch (C5Hio05)„. — Pure starch is a glistening, white, granular 
powder having a peculiar feeling when rubbed between the thumb and 
finger. It is a very hygroscopic, commercial starch containing about i8% 
of moisture. Starch is very widely distributed in the vegetable kingdom, 
occurring in almost every plant at some stage in its growth. 

Starch is insoluble in cold water, alcohol, and ether; it is soluble in 
hot water, though not without change. By boiling with dilute acids, 
starch is first converted by hydrolysis into a mixture of dextrin and malt- 
ose, and finally by prolonged boiling into dextrose. Malt extract also 
hydrolizes starch in solution. 

Detection. — Starch is best detected, when present to any appreciable 
extent in any mixture, by boiling a portion of the sample in water, cooling, 
and applying a solution of iodine. A characteristic blue color is pro- 
duced if starch is present. Very small amounts of starch are best iden- 
tified in powdered mixtures by applying a drop of a solution of iodine 
to the dry powder on a microscope slide, or, better, to the powder pre- 
viously rubbed out with water on a slide under a cover-glass; the starch 
granules, if present, will be colored intensely blue by the iodine, and are 
at once rendered apparent when viewed through the microscope. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 289 

Though the cereal and vegetable starches, whatever their origin, are 
identical chemically, the various starch granules have certain character- 
istics, when viewed under the microscope, that render their identifi- 
cation easy in most cases. A knowledge of the microscopical appear- 
ance of the common vegetable starches is of the utmost importance to 
the public analyst, who frequently finds them as adulterants of various 
foods such as coffee, cocoa, spices, etc. For microscopical examination, 
powdered samples should be ground fine enough to pass through a 60 or 
80 mesh sieve. 

Classification. — As seen under the microscope the starch granules 
of various grains and vegetables differ in form, size, and often in their 
manner of grouping. Thus, at the outset, the common starches may be 
divided as to the microscopical form of their granules into three classes, 
viz., lenticular, irregularly oval, and polygonal. To the first class, in which 
the starch granule has in general the circular disk form, belong rye, wheat, 
and barley. Representing the second or irregularly elliptical class are 
the pea, bean, potato, and arrowroot. In the third, or polygonal class, 
should be included corn, oats, buckwheat, and rice. In thus character- 
izing the distinguishing forms as lenticular, oval, and polygonal, it should 
be borne in mind that while the tendency of the most typical starch granules 
in each class, when viewed in normal position, is toward the circular, the 
oval, or the polygonal as the case may be, it is not by any means true that 
all or even most of the granules in any one instance perfectly conform 
to one of these shapes throughout. Thus, lenticular wheat granules, when 
viewed edgewise, will appear elliptical, and are often distorted in shape, 
especially when roasted; and polygonal buckwheat granules may in 
many instances have such obtuse angles as to appear circular. It is the 
general trend of all the starches toward one or another of these shapes 
that suggests the classification. 

The identification of the various starches morphologically is indeed 
the most natural and ready method. Not only the character of the starch, 
but also its approximate amount, when present in mixtures, can in many 
instances be ascertained by a careful examination with the rriicroscope. 
The analyst should be provided with samples of starches of known 
purity conveniently at hand, and in all doubful cases these should be 
referred to for comparison. 

Wheal Starch (Fig. 152, PI. VIII). — This starch is frequently present 
in adulterated pepper, mustard, ginger, cocoa, coffee, and other foods. 
Its granules occur for the most part in two sizes, of which the larger 



290 FOOD INSPECTION AND ANALYSIS. 

are lenticular, varying from 0.021 mm. to 0.041 mm., or rarely c.050 
mm., in diameter, while the smaller are rounded or polygonal, averaging 
about 0.005 mm. in diameter. The smaller granules are grouped irregu- 
larly in and around the larger, there being six to ten of the former to 
one of the latter. The larger granules are, however, the most distinctly 
characteristic, and are usually readil)- recognized in a mixture, not only 
by their shape, but by reason of the concentric rings with which they are 
provided, and which are generally but not always apparent. 

Barley Starch (Fig. 124, PI. I). — This much resembles wheat, in that 
it has two sizes of granules, but both sizes are respectively smaller than 
those of wheat, though present in about the same proportion. The 
larger lenticular disk-like granules vary from 0.013 mm. to 0.035 mm. in 
diameter, while the smaller average 0.003 "^"i- The concentric rings are 
less apparent in the barley than in the wheat. 

Rye Starch (Fig. 148, PI. VII) has also two sizes of granules, but 
the larger vary from 0.025 mm. to over 0.05 mm. in diameter, and are 
considerably larger than the corresponding wheat granules. The smaller 
granules average about 0.004 "ini- in diameter. As in the case of wheat 
and barley, the larger granules are lenticular, while the smaller are 
rounded or polygonal. The concentric rings are usually indistinct in the 
large granules, and many of these show cross-shaped rifts in the center. 

Corfi Starch (Fig. 133, PI. IV). — This starch is a common adulterant 
of spices, cocoa, and other foods. It is placed in a series of four cereal 
starches whose granules are polygonal, and all of which show more or 
less tendency to arrange themselves in close contact side by side in 
masses suggestive of a tessellated or mosaic floor. Arranged in order 
of the size of their grains, these starches are: Corn, buckwheat, oats, 
and rice. Corn starch granules tend toward the hexagonal in shape, 
varying from 0.007 "^^- to 0.035 mm. in diameter, and having very 
marked rifted hila. They are most readily recognized in any mixture, 
and from their size are readily distinguishable from the other polygonal 
starches, which never reach 0.017 ™™' i^^ diameter. 

Buckwheat Starch (Fig. 128, PL II, and Fig. 129, PI. III). — This is a 
very common adulterant of many spices, especially pepper, which, as 
shown in Fig. 256, PI. XXXIV, it much resembles in the manner in 
which its masses of granules group themselves, conforming to the shape 
of the cells. The individual granules are commonly c.cc6 mm. to 0.012 
mm. in diameter. Curious rod-shaped aggregates of two to four indi- 
viduals are of frequent occurrence. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 291 

Oat Starch (Fig. 139, PI. V). — The granules of this starch vary from 
0.002 mm. to 0.012 mm. in diameter, and are polygonal, or less often 
rounded or spindle-shaped in form. They have no rings or hila, and 
arrange themselves in rounded aggregates of from two to many granules 
that at first sight might be mistaken for large grains; careful examina- 
tion, however, shows the dividing lines. 

Rice Starch (Fig. 143, PI. VI).— The granules of rice starch resemble 
closely those of oats both in form and size, but spindle-shaped forms are 
not present. As in the case of oats, the granules are often united to form 
rounded aggregates. 

Starches of the Pea and Bean. — The starches of these legumes much 
resemble each other, and are with difficultly distinguished one from the 
other (see Fig. 164, PI. XI, and Fig. 154, PI. IX). The granules are 
more nearly oval than most other starches, and have both concentric 
rings and elongated hila. The granules of the pea show a less distinct 
hilum than those of the bean, and some of them are irregularly swollen. 
Both peas and beans roasted are commonly used as adulterants of 
Coffee. 

Arrowroot. — There are many varieties of arrowroot, including Jamaica, 
Bermuda, East Indian, Austrahan, and others, all having certain varia- 
tions in form and size, but resembling each other in a general way. 
Fig. 167, PI. XII, shows the Bermuda arrowroot, the granules of which 
are somewhat egg-shaped, being usually smaller at one end than the 
other, and having rifted hila near the small end. 

Potato Starch (Fig. 165, PI. XII). — This starch has large, irregularly 
oval granules, with very apparent hila situated eccentrically near one 
end, and with rings around the hilum. The granules are about 0.07 mm. 
in large diameter. Fig. 134, PI. IV, and Fig. 166, PI. XII, show corn 
and potato starch when viewed with polarized light with crossed Nicol 
prisms, the specimens being mounted in Canada balsam. 

Tapioca Starch. — The granules of this starch, as shown in Fig. 168, 
PI. XII, are more uniform in size throughout than those already de- 
scribed, averaging about 0.018 mm. in diameter, and being quite smoothly 
circular, without concentric rings, but having a distinctly dotted hilum in 
the center. Many of the grains are cup-shaped, as if a segment of the 
circle had been removed. 

Sago Starch (Fig. 172, PI. XIII.) — The granules of sago starch vary 
much in size, and might be called irregularly ellipsoidal in shape with 
one or more truncated surfaces. Some of them have indistinct concentric 



292 FOOD INSPECTION AND ANALYSIS. 

rings, and in some, but not all, a hilum is apparent, usually near one end 
of the granule. 

Microscopical Appearances of Starches with Polarized Light.^With 
polarized light starch granules show dark crosses, the point of inter- 
section being at the hilum (Fig. i66, PI. XII). These crosses vary 
in distinctness with the variety. Certain of the starches show a play 
of colors with polarized light and a selenite plate, especially those whose 
granules have some sort of hilum. This is particularly striking in such 
starches as corn, tapioca, potato, and arrowroot. Blyth has made the 
phenomenon a means of classification of the starches, but the writer 
considers their appearance with ordinary light sufficient for identifica- 
tion. Canada balsam is the best mountant for examination in polar- 
ized light. 

Estimation of Starch. — Direct Acid Conversion. — By this method the 
hemicellulose, if present, or such of the carbohydrates as are capable of 
being converted to sugar, are reckoned in with the starch. Where little 
or none of the insoluble carbohydrates other than starch are present, as 
for instance in the case of commercial starches, this method is sufficiently 
accurate. 

Exhaust 3 grams of the finely divided substance on a fine but rapidly 
acting filter with ether by washing with 5 successive portions of 10 cc. 
each, and wash the residue first with 150 cc. of 10% alcohol and then 
with a little strong alcohol. Transfer by washing to a flask with 200 cc. 
of water and 20 cc. of hydrochloric acid (specific gravity 1.125), connect 
with a reflux condenser, and heat the flask in boiling water for 2^ hours. 
Cool, and carefully neutrahze with sodium hydroxide, clarifying if neces- 
sary with alumina cream. Mix well, make up the volume to 500 cc.^, 
filter, and determine the dextrose in an aliquot part of the filtrate by 
any of the methods for dextrose. Convert dextrose to starch by the 
factor 0.9. 

Diastase Method. — By this method the hemicellulose is not con- 
verted, only the starch being acted upon. Hence for exact work in the 
presence of other insoluble carbohydrates this method is to be recom- 
mended. Under the action of diastase, starch is first converted into 
maltose and dextrin, and finally into dextrose, in somewhat the following 
manner: 

I2C6Hio05-l-4H20=4Ci2H220ii -h2Ci2H2oOio 

starch Maltose Dextrin 

Cl2H220ii+HoO = 2C6Hi206 d 0H20O10 + 2H2O = 2C6H12O6 

Maltose Dextrose Dextrin Dextrose 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 293 

Exhaust 3 grams of the material, ground to an impalpable powder, 
with ether and alcohol as in the acid conversion method, wash the residue 
into a beaker with 50 cc. of w"ter and immerse in a boiling water-bath. 
Keep in the bath for 15 minutes or until completely gelatinized, stirring 
constantly, and cool to 55° C. Add 20 cc. of malt extract and digest 
at 55° C. one hour. Heat again to boiling, boil for 15 minutes, replacing 
the water lost by evaporation, cool to 55° C, and digest as before with 
20 cc. of malt extract for one hour or until the residue treated with iodine 
solution shows no starch under the microscope. Cool, make up to 250 
cc, filter, pipette 200 cc. into a flask, add 20 cc. of hydrochloric acid (specific 
gravity 1.125) and proceed as in the acid conversion method. Correct 
for the copper-reducing power of tiie malt extract as below. 

Preparation of Malt Extract. — Digest at room temperature 10 grams of 
freshly pulverized malt with 200 cc. of water for 2 to 3 hours with occasional 
shaking and filter. Determine the amount of dextrose in a given volume 
of the extract after heating with acid, etc., as in the actual analysis and 
make the proper correction. 

Use of ^^ Animal Diastase y — Pancreatin and similar powdered prepara- 
tions, such as " vera diastase " and " panase," obtained from the pancreas 
of cattle and hogs, are preferable to diastase as starch-converting reagents, 
since, as a rule, they have no copper-reducing power, thus obviating a 
correction. 

Use instead of the malt extract the same amount, viz., 20 cc, of a 
0.5% aqueous solution of powdered U. S. P. pancreatin in starch deter, 
minations as above described. 

Determination of Sugars in Grain and Cereal Products. — Method of 
Bryan, Given and S traughn.'^— F\a,ce 12 grams of the material in a 300- 
cc graduated flask (if acid add 1-3 grams of precipitated calcium car- 
bonate), add 150 cc. of 50% (by vol.) alcohol (carefully neutraHzed), mix 
and boil on a steam bath under a reflux condenser for one hour. Cool, 
and if desired allow to stand overnight. Make up to volume with neutral 
95% alcohol, mix, allow to settle, pipette 200 cc. into a beaker, and evaporate 
on the steam bath to 20-30 cc. Transfer to a loo-cc graduated flask with 
water, add enough saturated normal lead acetate solution to produce 
a flocculent precipitate, and allow to stand 15 minutes or if desired over- 
night. Make up to the mark with water and pass through a folded 
filter, saving all the filtrate. Precipitate the lead with anhydrous sodium 

* U. S. Dept. of Agric, Bur. of Chem., Circ. 71. 



294 FOOD INSPECTION AND ANALYSIS. 

carbonate, allow to stand 15 minutes and pour onto an ashless filter. 
Dilute 25 CO. of this clear filtrate with 25 cc. of water and determine reduc- 
ing sugars by the Munson and Walker method (p. 622). 

In a 100 cc. graduated flask place 50 cc. of the same filtrate, neutralize 
to htraus paper with acetic acid, add 5 cc. of concentrated hydrochloric 
acid, and let stand overnight (or if desired 48 hours) for inversion. Neu- 
tralize in a large beaker with anhydrous sodium carbonate; return to 
the 100 cc. flask and make up to the mark. Filter and determine total 
sugars as invert in 50 cc. of the filtrate by the Munson and Walker 
method. 

Multiply the difference between the percentages of invert sugar before 
and after inversion by 0.95, thus obtaining the per cent of sucrose. Cor- 
rect the percentages of both sucrose and reducing sugars for the volume 
of the alcohol precipitate by multiplying by 0.97. 

Cellulose forms the framework of all vegetable organisms, being 
next to water, the most abundant substance in the vegetable kingdom. 
Pure cellulose is white, translucent, and of fibrous or silky texture. It 
is insoluble in water, alcohol, and ether, but dissolves readily in an 
ammoniacal solution of cupric hydroxide known as Schweitzer's Reagent 
or " cuprammonia," (p. 80). Cellulose turns violet when treated with 
chloriodide of zinc, and blue when treated with sulphuric acid and iodine 
in potassium iodide (p. 78). 

The " crude fiber," as determined in foods, being the portion that 
resists the action of hot dilute acid and alkali, is composed largely of 
cellulose. 

The Pentosans are amorphous, insoluble in water, but solubb in dilute 
alkali, and are converted by boiling with dilute acids into so-called pentose 
suo^ars, the best known of which are xylose and arabinose, corresponding 
to the pentosans xylan and araban respectively. Hemicellulose is the 
more appropriate generic term for the insoluble carbohydrates capable 
of hydrolysis by acids to sugars, inasmuch as there are insoluble 
bodie besides the pentosans that may thus be converted into sugar, 
such as the hexosans, hydrolyzed by acid to hexose sugars, mannose, 
galactose, etc. Since the greater portion of these insoluble hydroliz- 
able carbohydrates are pentosans, it is simpler to calculate them all as 
such. 

Determination of Pentosans. — Pentosans are determined either by 
hydrolyzing to reducing sugar, and estimating the latter as described on 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 295 

page 304 (Sone's method) or by calculation from the furfural* yielded 
on distillation with hydrochloric acid, as carried out in the provisional 
method of the A. O. A. C.f as follows: 

Place 3 grams of the material in a flask together with 100 cc. of 12% 
hydrochloric acid (specific gravity 1.06) and several pieces of recently 
heated pumice stone, connect with a condenser and heat on a wire gauze, 
rather gently at first, using a gauze top to distribute the flame so as to 
distil over 30 cc. in about ten minutes and passing the distillate through 
a small filter. Replace the 30 cc. driven over with a like amount of the 
12% acid added through a separatory funnel in such a manner as to wash 
down the particles on the sides of the flask and continue the process until 
the distillate amounts to 360 cc. To the distillate add gradually a quantity 
of phloroglucinol (free from diresorcin) dissolved in 12% hydrochloric 
acid, about double that of the furfural expected. The solution first turns 
yellow, then green, and soon an amorphus greenish precipitate appears, 
which rapidly grows darker, finally becoming almost black. Make the 
solution up to 400 cc. with 12% hydrochloric acid and allow to stand over- 
night. 

Filter the amorphous black precipitate on a Gooch crucible, wash 
with 150 cc. of water, keeping the precipitate covered with the liquid 
until the last portion has run through, dry for four hours at the temperature 
of boiling water, cool in a weighing bottle and weigh. Calculate by 
Krober's formulae as follows : 

(a) For weight of phloroglucide " a " under 0.03 gram: 

Furfural = (a + 0.005 2) X o. 5 1 70. 
Pentoses = (a + 0,0052) Xi. 01 70. 
Pentosans = (a + 0.0052) X 0.8949, 



* Furfural or f urf uraldehyde (CiH^Oz) is the aldehyde of pyromucic acid. It is a color- 
less liquid, having an odor suggestive of cassia. Its boiling-point is 162° and its specific 
gravity 1.164. It is sparingly soluble in water and readily soluble in alcohol. Nearly 
half the tissue of ordinary bran, exclusive of proteins and starch, yields furfural on distilla- 
tion with acid. 

t U. S. Dept. of Agric, Bur. of Chem,, Bui. 107 (rev.), p. 54. 



296 FOOD INSPECTION AND ANALYSIS. 

(b) For weight of phloroglucide " a " over 0.300 gram. 

Furfural = (a + 0.005 2) X 0.5 180. 
Pentoses =(a+o.oo52)X 1.0026. 
Pentosans = (a + 0.005 2) X 0.8824. 

For weight of phloroglucide "a" from 0.03 to 0.300 gram use Krober's 
table (pp. 297-303) to calculate the weight of pentoses (arabinose, 
xylose), and pentosans (araban, xylan). 

The reactions that take place are thought to be somewhat as follows: 

C5H80, + H20 = C5H,o05. 

Pentosan Pentose 

Pentose Furfural 

2C5H402 + C6H603==Ci6Hi206 + H20. 

Furfural Phloroglucinol Phloroglucide 

The theoretical yield of phloroglucide should be 2.22 parts to one of 
furfural, but in practice this is never obtained. The varying factors for 
calculation as above given are based on experiment. 

The phloroglucinol used should be free from diresorcin. To test for 
the latter, dissolve the reagent in acetic anhydride, heat nearly to boiling, 
and add a few drops of concentrated sulphuric acid. If more than a 
faint violet color is produced, the phloroglucinol should be purified as 
follows : 

Heat in a beaker about 300 cc. of hydrochloric acid (sp. gr. 1.06) 
and II grams of commercial phloroglucinol, added in small quantities 
at a time, stirring constantly until it has almost dissolved. Some im- 
purities may resist solution, but it is unnecessary to dissolve them. 
Pour the hot solution into a sufficient quantity of the same hydrochloric 
acid (cold) to make the volume 1500 cc. Allow it to stand at least 
overnight — better several days — to allow the diresorcin to crystallize out, 
and filter immediately before using. The solution may turn yellow, 
but this does not interfere with its usefulness. In using it, add the 
volume containing the required amount to the distillate. 



1 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



297 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID. 



I 


2 


3 


4 


S 


6 


•7 


8 . 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.030 


0.0182 


0.0391 


0.0344 


0.0324 


0.0285 


0-0358 


0.0315 


-031 


.0188 


.0402 


-0354 


-0333 


.0293 


.0368 


.0324 


.032 


-0193 


-0413 


-0363 


.0342 


.0301 


-0378 


-0333 


•033 


.0198 


.0424 


■0373 


-0352 


.0309 


.0388 


-0341 


-034 


.0203 


•0435 


-0383 


.0361 


•0317 


.0398 


■0350 


-035 


.0209 


.0446 


-0393 


.0370 


.0326 


.0408 


•0359 


.036 


.0214 


-0457 


.0402 


•0379 


-0334 


.0418 


.0368 


.037 


.0219 


.0468 


.0412 


.0388 


.0342 


.0428 


-0377 


.038 


.0224 


.0479 


.0422 


.0398 


•0350 


-0439 


.0386 


•039 


.0229 


.0490 


-0431 


.0407 


-0358 


.0449 


•0395 


.040 


•0235 


.0501 


.0441 


.0416 


.0366 


•0459 


.0404 


.C41 


.0240 


.0512 


-0451 


.0425 


-0374 


.0469 


-0413 


.042 


.0245 


•0523 


.0460 


• 0434 


.0382 


.0479 


.0422 


.C43 


.0250 


■0534 


.0470 


-0443 


.0390 


.0489 


-0431 


.C44 


■025s 


■0545 


.0480 


.0452 


.0398 


.0499 


.0440 


.045 


.0260 


.0556 


.0490 


.0462 


.0406 


.0509 


.0448 


.046 


.0266 


.0567 


.0499 


.0471 


.0414 


■0519 


-0457 


.047 


.0271 


-0578 


.050*9 


.0480 


.0422 


.0529 


.0466 


.048 


.0276 


.0589 


-0519 


.0489 


.0430 


.0539 


-0475 


,049 


.0281 


.0600 


.0528 


.0498 


.0438 


-0549 


.0484 


.050 


.0286 


.0611 


-0538 


-0507 


.0446 


■0559 


.0492 


.051 


.0292 


.0622 


.0548 


.0516 


-0454 


.0569 


.0501 


.052 


.0297 


•0633 


•0557 


-0525 


.0462 


•0579 


.0510 


.053 


.0302 


.0644 


-0567 


-0534 


.0470 


.0589 


-0519 


.054 


.0307 


■0655 


.0576 


-0543 


.0478 


•0599 


.0528 


.055 


.0312 


.0666 


.0586 


.0553 


.0486 


.0610 


.0537 


.056 


.0318 


.0677 


.0596 


.0562 


.0494 


.0620 


.0546 


.057 


.0323 


.0688 


.0605 


-0571 


.0502 


.0630 


-0555 


.058 


.0328 


.0699 


.0615 


.0580 


.0510 


.0640 


.0564 


.059 


.0333 


.0710 


.0624 


.0589 


.0518 


.0650 


•0573 


.060 


-0338 


.0721 


.0634 


.0598 


.0526 


.0660 


.0581 


.061 


-0344 


.0732 


.0644 


.0607 


-0534 


.0670 


.0590 


.062 


-0349 


•0743 


-0653 


.0616 


.0542 


.0680 


-0599 


.063 


-0354 


-0754 


.0663 


.0626 


-0550 


.0690 


.0608 


.064 


-0359 


.0765 


.0673 


-0635 


■0558 


.0700 


.0617 


.065 


.0364 


.0776 


.0683 


.0644 


.0567 


.0710 


.0625 


.066 


.0370 


.0787 


.0692 


-0653 


-0575 


.0720 


.0634 


.067 


.0375 


.0798 


.0702 


.0662 


-0583 


.0730 


.0643 


.068 


.0380 


.0809 


.0712 


.0672 


■0591 


.0741 


.0652 


.069 


.0385 


.0820 


.0721 


.0681 


•0599 


■0751 


.0661 



298 



FOOD INSPECTION AND ANALYSIS. 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHI.OROG'LIJCID— Continued. 



I 


2 


3 


4 


5 


6 


7 


8 


Fhloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.070 


0.0390 


0.0831 


0.0731 


0.0690 


0.0607 


0.0761 


0.0670 


.071 


.0396 


.0842 


.0741 


.0699 


.0615 


.0771 


.0679 


.072 


.0401 


.0853 


.0750 


.0708 


.0623 


.0781 


.0688 


.073 


.0406 


.0864 


.0760 


.0717 


.0631 


.0791 


.0697 


.074 


.0411 


-0875 


.0770 


.0726 


.0639 


.0801 


.0706 


.075 


.0416 


.0886 


.0780 


.0736 


.0647 


.0811 


.0714 


.076 


.0422 


.0897 


.0789 


■0745 


.0655 


.0821 


.0722 


.077 


.0427 


.0908 


.0799 


.0754 


.0663 


.0831 


•0731 


.078 


.0432 


.0919 


.0809 


.0763 


.0671 


.0841 


.0740 


.079 


.0437 


.0930 


.0818 


.0772 


.0679 


.0851 


.0749 


.080 


.0442 


.0941 


.0828 


.0781 


.0687 


.0861 


.0758 


.081 


.0448 


.0952 


.0838 


.0790 


.0695 


.0871 


.0767 


.082 


.0453 


.0963 


.0847 


.0799 


.0703 


.0881 


.0776 


.083 


.0458 


.0974 


.0857 


.0808 


.0711 


.0891 


.0785 


.084 


.0463 


.0985 


.0867 


.0817 


.0719 


.0901 


.0794 


,085 


.0468 


.0996 


.0877 


.0827 


.0727 


.0912 


. 0803 


.086 


.0474 


.1007 


.0886 


-0836 


•0735 


.0922 


.0812 


.087 


.0479 


.1018 


.0896 


.0845 


-0743 


.0932 


.0821 


.088 


.0484 


.1029 


.0906 


.0854 


.0751 


.0942 


.0830 


.089 


.0489 


.1040 


.0915 


.0863 


-0759 


.0952 


.0838 


.090 


.0494 


.1051 


.0925 


.0872 


.0767 


.0962 


.0847 


.091 


.0499 


.1062 


-0935 


.0881 


•0775 


.0972 


.0856 


.092 


.0505 


-1073 


.0944 


.0890 


-0783 


.0982 


.0865 


.093 


.0510 


.1084 


•0954 


.0900 


.0791 


.0992 


.0874 


.094 


.0515 


■109s 


.0964 


.0909 


.0800 


.1002 


.0883 


.095 


.0520 


.1106 


.0974 


.0918 


.0808 


.1012 


.0891 


.096 


•0525 


.1117 


.0983 


.0927 


.0816 


.1022 


.0899 


.097 


.0531 


.1128 


•0993 


.0936 


.0824 


.1032 


.0908 


.098 


.0536 


."39 


.1003 


.0946 


.0832 


.1043 


.0917 


.099 


-0541 


.1150 


.1012 


•0955 


.0840 


-1053 


.0926 


.100 


.0546 


.1161 


.1022 


.0964 


.0848 


.1063 


.0935 


.101 


-0551 


.1171 


.1032 


-0973 


.0856 


-1073 


.0944 


.102 


.0557 


.1182 


.1041 


.0982 


.0864 


.1083 


-0953 


•103 


.0562 


-"93 


.1051 


.0991 


.0872 


.1093 


.0962 


.104 


.0567 


.1204 


.1060 


.1000 


.0880 


.1103 


.0971 


.105 


.0572 


.1215 


.1070 


.1010 


.0888 


.1113 


.0976 


.106 


.0577 


.1226 


.1080 


.1019 


.0896 


.1123 


.0988 


.107 


.0582 


.^237 


.1089 


.1028 


.0904 


• ^^33 


.0997 


.108 


.0588 


.1248 


.1099 


.1037 


.0912 


.1143 


.1006 


.109 


-0593 


.1259 


.1108 


.1046 


.0920 


-1153 


.1015 



CEREALS, VEGETABLES, ERUITS, AND NUTS. 



299 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (Con/i«MC(f). 



I 


2 


3 


4 


Xylose. 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylan. 


Pentose. 


Pentosan. 


O.IIO 


0.0598 


0.1270 


0.1118 


0-1055 


0.0928 


O.I163 


0.1023 


• III 


.0603 


.1281 


.1128 


.1064 


.0936 


•"73 


.1032 


.112 


.0608 


.1292 


-1 137 


■1073 


.0944 


.1183 


.1041 


."3 


.0614 


-1303 


.1147 


.1082 


.0952 


•"93 


.1050 


.114 


.0619 


.1314 


.1156 


.1091 


.0960 


.1203 


•1059 


."5 


.0624 


.1325 


.1166 


.1101 


.0968 


.1213 


.1067 


.ii6 


.0629 


■ ^33(> 


.1176 


.1110 


.0976 


.1223 


.1076 


.117 


.0634 


-1347 


.1185 


.1119 


.0984 


•1233 


.1085 


.118 


.0640 


-1358 


-1 195 


.1128 


.0992 


•1243 


.1094 


.119 


.0645 


.1369 


.1204 


•I 137 


.1000 


•1253 


.1103 


.120 


.0650 


.1380 


.1214 


.1146 


.1008 


.1263 


.nil 


.121 


-0655 


■I391 


.1224 


-I155 


.1016 


-1273 


.1120 


.122 


.0660 


.1402 


-1233 


.1164 


.1024 


.1283 


.1129 


.123 


.0665 


-I413 


-1243 


-I173 


.1032 


.1293 


.1138 


.124 


.0671 


.1424 


•1253 


.1182 


.1040 


•1303 


.1147 


.125 


.0676 


-1435 


.1263 


.1192 


.1049 


•I314 


.1156 


.126 


.0681 


.1446 


.1272 


.1201 


-1057 


-1324 


.1165 


.127 


.0686 


-1457 


.1282 


.1210 


.1065 


•1334 


• I174 


.128 


.0691 


.1468 


.1292 


.1219 


■1073 


.1044 


.11S3 


• I 29 


.0697 


-1479 


.1301 


.1228 


.1081 


•1354 


.1192 


• 130 


.0702 


.1490 


.1311 


•1237 


.X089 


•1364 


.1201 


.131 


.0707 


.1501 


.1321 


.1246 


.1097 


•1374 


.1210 


.132 


.0712 


.1512 


.1330 


-1255 


.1105 


.1384 


.1219 


.133 


.0717 


-1523 


-1340 


.1264 


.1113 


•1394 


.1227 


.134 


.0723 


-1534 


•1350 


■1273 


.1121 


.1404 


.1236 


.135 


.0728 


•1545 


.1360 


.1283 


.1129 


.1414 


.1244 


.136 


•0733 


■1556 


.1569 


.1292 


-II37 


.1424 


•1253 


.137 


.0738 


-1567 


.1379 


.1301 


-II45 


-1434 


.1262 


.138 


•0743 


-1578 


.1389 


.1310 


•II53 


.1444 


.1271 


• 139 


.0748 


.1589 


.1398 


-I319 


. I161 


-1454 


.1280 


.140 


-0754 


.1600 


.1408 


.1328 


.1169 


.1464 


.1288 


.141 


.0759 


.1611 


.1418 


-1337 


.1177 


.1474 


.1297 


.142 


.0764 


.1622 


.1427 


.1346 


.1185 


.1484 


.1306 


.143 


.0769 


■^^33 


-1437 


.1355 


-1 193 


.1494 


•1315 


.144 


.0774 


.1644 


.1447 


.1364 


.1201 


• 1504 


•1324 


.145 


.0780 


.1655 


.1457 


-1374 


.1209 


•I515 


•^333 


.146 


.0785 


.1666 


.1466 


■1383 


.1217 


•1525 


• 1342 


.147 


.0790 


.1677 


.1476 


.1392 


.1225 


•1535 


•1351 


.148 


•079s 


.1688 


.i486 


.1401 


.1233 


.1545 


.1360 " 


.149 


,0800 


.1699 


•1495 


.1410 


.1241 


.1555 


.1369 



300 



FOOD INSPECTION AND ANALYSIS. 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (Con/i«Me(f). 



I 


2 


3 


4 


S 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.150 


0.0805 


0.1710 


0-1505 


0.1419 


0.1249 


0.1565 


0-1377 


.151 


.0811 


.1721 


-1515 


.1428 


-1257 


-1575 


.1386 


•152 


.0816 


.1732 


.1524 


-1437 


.1265 


.1585 


•1395 


•153 


.0821 


•1743 


.1534 


.1446 


-1273 


.1595 


.1404 


.154 


.0826 


.1754 


-1544 


.1455 


.1281 


.1605 


.1413 


.155 


.0831 


.1765 


-1554 


.1465 


.1289 


.1615 


.1421 


.156 


.0837 


.1776 


•1563 


.1474 


.1297 


.1625 


.1430 


-157 


.0842 


.1787 


•1573 


.1483 


-1305 


-1635 


•1439 


.158 


.0847 


.1798 


■1583 


.1492 


■ ^3^3 


.1645 


.1448 


.159 


.0852 


.1809 


•1592 


.1501 


.1321 


-1655 


.1457 


.160 


.0857 


.1820 


.1602 


.1510 


.1329 


.1665 


-1465 


.161 


.0863 


.1831 


.1612 


-1519 


-1337 


-167s 


1474 


.162 


.0868 


.1842 


.1621 


.1528 


-1345 


.1685 


.1483 


.163 


.0873 


-1853 


.1631 


-1537 


-1353 


.1695 


.1492 


.164 


.0878 


.1864 


.1640 


.1546 


.1361 


.1705 


.1501 


.165 


.0883 


.1875 


.1650 


-1556 


.1369 


.1716 


.1510 


.166 


.0888 


.1886 


.1660 


.1565 


•1377 


.1726 


.1519 


.167 


.0894 


.1897 


.1669 


• 1574 


-1385 


-1736 


.1528 


.168 


.0899 


.1908 


.1679 


.1583 


.1393 


.1746 


•1537 


.169 


.0904 


.1919 


.1688 


-1592 


.1401 


.1756 


.1546 


.170 


.0909 


.1930 


.1698 


.1601 


.1409 


.1766 


.1554 


.171 


.0914 


.1941 


.1708 


.1610 


.1417 


.1776 


.1563 


.172 


.0920 


•1952 


.1717 


.1619 


.1425 


.1786 


.1572 


.173 


.0925 


.1963 


.1727 


.1628 


-1433 


.1796 


.1581 


.174 


.0930 


•1974 


.1736 


-1637 


.1441 


.1806 


•1590 


•175 


•0935 


.1985 


.1746 


.1647 


.1449 


.1816 


.1598 


.176 


.0940 


.1996 


•1756 


.1656 


• 1457 


.1826 


.1607 


.177 


.0946 


.2007 


■1765 


.1665 


-1465 


.1836 


.1616 


.178 


•0951 


.2018 


.1775 


.1674 


-1473 


.1846 


.1625 


.179 


.0956 


.2029 


.1784 


.1683 


.1481 


.1856 


.1634 


.180 


.0961 


.2039 


-1794 


.1692 


.1489 


.1866 


.1642 


.181 


.0966 


.2050 


.1804 


.1701 


-1497 


.1876 


.1651 


.182 


.0971 


.2061 


.1813 


.1710 


■ 1505 


.1886 


.1660 


.183 


.0977 


.2072 


.1823 


.1719 


■1513 


.1896 


.1669 


.184 


.0982 


.2082 


.1832 


.1728 


.1521 


.1906 


.1678 


.185 


.0987 


.2093 


.1842 


•1738 


.1529 


.1916 


.1686 


.186 


.0992 


.2104 


.1851 


-1747 


-1537 


.1926 


.169s 


.187 


.0997 


.2115 


.1861 


■1756 


-1545 


.1936 


.1704 


.188 


.1003 


.2126 


.1870 


-1765 


.1553 


.1946 


.17I8 


.189 


.1008 


.2136 


.1880 


•1774 


.1561 


.1955 


.1721 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



301 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM Pm^OROGLUCIB— (Continued). 



I 


2 


3 


4 


5 


6 


7 


8 


j'hloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.190 


0.1013 


0.2147 


0.1889 


0.1783 


0.1569 


0.1965 


0.1729 


.191 


.1018 


.2158 


.1899 


.1792 


-1577 


-1975 


-1738 


192 


.1023 


.2168 


.1908 


.1801 


.1585 


.1985 


.1747 


.193 


.1028 


.2179 


.1918 


.1810 


.1593 


.1995 


.1756 


.194 


-1034 


.2190 


.1927 


.1819 


,1601 


• 2005 


.1764 


.195 


.1039 


.2201 


.1937 


.1829 


.1609 


.2015 


-1773 


.196 


.1044 


.2212 


.1946 


.1838 


.1617 


.2025 


.1782 


.197 


.1049 


.2222 


.1956 


.1847 


.1625 


•2035 


.1791 


,198 


.1054 


.2233 


.1965 


.1856 


•^^33 


.2045 


.1800 


.199 


.1059 


.2244 


•1975 


.1865 


.1641 


•2055 


.1808 


,200 


.1065 


.2255 


.1984 


.1874 


.1649 


.2065 


.1817 


,201 


.1070 


.2266 


.1994 


.1883 


.1657 


.2075 


.1826 


,202 


-1075 


.2276 


.2003 


.1892 


.1665 


.2085 


.1835 


,203 


.1080 


.2287 


.2013 


.1901 


.1673 


.2095 


.1844 


.204 


.1085 


.2298 


.2022 


.1910 


.i68r 


.2105 


.1853 


.205 


.1090 


.2309 


.2032 


.1920 


.1689 


.2115 


.1861 


^^06 


.1096 


.2320 


.2041 


.1929 


.1697 


.2125 


.1869 


.^07 


.1101 


.2330 


.2051 


.1938 


-1705 


-2134 


.1878 


.;o8 


.1106 


.2341 


.2060 


-1947 


-1713 


.2144 


.1887 


.^09 


.IIll 


.2352 


.2069 


.1956 


.1721 


-2154 


.1896 


,210 


.1116 


.2363 


.2079 


.1965 


.1729 


.2164 


.1904 


^211 


.1121 


-2374 


.2089 


-1975 


-1737 


• 2174 


-I913 


212 


.1127 


.2384 


.2098 


.1984 


-1745 


.2184 


.1922 


.213 


.1132 


-2395 


.2108 


■1993 


.1753 


.2194 


•1931 


.214 


-"37 


.2406 


.2117 


.2002 


.1761 


.2204 


.1940 


.215 


.1142 


.2417 


.2127 


.2011 


.1770 


.2214 


.1948 


.216 


.1147 


.2428 


.2136 


.2020 


.1778 


.2224 


-1957 


.217 


.1152 


.2438 


.2146 


.2029 


.1786 


.2234 


.1966 


.218 


.1158 


.2449 


.2155 


.2038 


.1794 


.2244 


.1974 


.219 


.1163 


.2460 


.2165 


.2047 


.1802 


-2254 


.1983 


.220 


.1168 


.2471 


-2174 


.2057 


.r8io 


.2264 


.1992 


.221 


-1173 


.2482 


.2184 


.2066 


.1818 


.2274 


.2001 


.222 


.1178 


.2492 


.2193 


.2075 


.1826 


.2284 


.2010 


.223 


.1183 


-2503 


-2203 


.2084 


.1834 


.2294 


.2019 


.224 


.1189 


.2514 


.2212 


.2093 


.1842 


.2304 


.2028 


.225 


.1194 


.2525 


.2222 


.2102 


.1850 


.2314 


.2037 


.226 


.1199 


-2536 


.2232 


.2111 


.1858 


.2324 


.2046 


.227 


.1204 


.2546 


.2241 


.2121 


.1866 


-2334 


.2054 


.228 


.1209 


.2557 


.2251 


.2130 


.1874 


.2344 


.2063 


.229 


.1214 


.2568 


.2260 


.2139 


.1882 


.2354 


.2072 



302 



FOOD INSPECTION AND ANALYSIS. 



PROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PHLOROGLUCID— (CoK/i«Med). 



I 


2 


3 


4 


5 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xylose. 


Xylan. 


Pentose. 


Pentosan. 


0.230 


0.1220 


0.2579 


0.2270 


0.2148 


0.1890 


0.2364 


0.2081 


.231 


.1225 


.2590 


.2280 


.2157 


.1898 


•2374 


.2089 


.232 


.1230 


.2600 


.2289 


.2166 


.1906 


-2383 


.2097 


.233 


.1235 


.2611 


.2299 


•217s 


.1914 


•2393 


.2106 


.234 


.1240 


.2622 


.2308 


.2184 


.1922 


,2403 


.2115 


•235 


.1245 


.2633 


.2318 


.2193 


.1930 


-2413 


.2124 


.236 


.1251 


.2644 


.2327 


.2202 


.1938 


.2423 


.2132 


.237 


.1256 


.2654 


■2337 


.2211 


.1946 


•2433 


.2141 


.238 


.1261 


.2665 


.2346 


.2220 


-1954 


.2443 


.2150 


.239 


.1266 


.2676 


.2356 


.2229 


.1962 


.2453 


.2159 


.240 


.1271 


.2687 


.2365 


.2239 


.1970 


.2463 


.2168 


.241 


.1276 


.2698 


-237s 


.2248 


.1978 


.2473 


.2176 


.242 


.1281 


.2708 


.2384 


.2257 


.1986 


.2483 


.2185 


.243 


.1287 


.2719 


.2394 


.2266 


.1994 


•2493 


,2194 


.244 


.1292 


.2730 


. . 2403 


.2275 


.2002 


•2503 


.2203 


.245 


.1297 


.2741 


• 2413 


.2284 


.2010 


.2513 


.2212 


.246 


.1302 


.2752 


.2422 


.2293 


.2018 


-2523 


.2220 


.247 


•1307 


.2762 


.2432 


.2302 


.2026 


.2533 


.2229 


.248 


.1312 


•2773 


.2441 


.2311 


.2034 


-2543 


.2238 


.249 


.1318 


.2784 


.2451 


.2320 


.2042 


.2553 


.2247 


.250 


.1323 


•2795 


.2460 


•2330 


.2050 


-2563 


.2256 


.251 


.1328 


.2806 


.2470 


•2339 


.2058 


•2573 


.2264 


.252 


•1333 


.2816 


.2479 


.2348 


.2066 


.2582 


.2272 


.253 


•1338 


.2827 


.2489 


•2357 


-2074 


•2592 


.2281 


.254 


•1343 


.2838 


.2498 


.2366 


.2082 


.2602 


.2290 


.255 


•1349 


.2849 


.2508 


.2375 


.2090 


.2612 


.2299 


.256 


-1354 


.2860 


.2517 


.2384 


.2098 


.2622 


.2307 


.257 


-1359 


.2870 


.2526 


.2393 


.2106 


.2632 


.2316 


.258 


.1364 


.2881 


•2536 


.2402 


.2114 


.2642 


-2325 


•259 


.1369 


.2892 


•2545 


.2411 


.2122 


.2652 


•2334 


.260 


•1374 


.2903 


•2555 


.2420 


.2130 


.2662 


•2343 


.261 


.1380 


.2914 


-2565 


.2429 


.2138 


.2672 


•2351 


.262 


.1385 


.2924 


■2574 


.2438 


.2146 


.2681 


-2359 


.263 


.1390 


•2935 


.2584 


.2447 


.2154 


.2691 


.2368 


.264 


•139s 


.2946 


•2593 


.2456 


.2162 


.2701 


.2377 


.265 


.1400 


•2957 


.2603 


.2465 


.2170 


.2711 


-2385 


.266 


• 1405 


.2968 


.2612 


.2474 


.2178 


.2721 


•2394 


.267 


.1411 


.2978 


.2622 


.2483 


.2186 


•2731 


.2403 


.268 


.1416 


.2989 


.2631 


.2492 


.2194 


.2741 


.2412 


.269 


.1421 


.3000 


.2641 


.2502 


.2202 


•2751 


.2421 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



303 



KROBER'S TABLE FOR DETERMINATION OF PENTOSES AND PENTOSANS 
FROM PWLOROGLUCIB— {Concluded). 



1 


2 


3 


4 


S 


6 


7 


8 


Phloroglucid 


Furfural. 


Arabinose. 


Araban. 


Xy lose. 


Xylan. 


Pentose. 


Pentosan. 


0.270 


0.1426 


0.3011 


0.2650 


O.2511 


0.2210 


0.2761 


0.2429 


.271 


■I431 


.3022 


.2660 


.2520 


.2218 


.2771 


.2438 


.272 


.1436 


•3032 


.2669 


.2529 


.2226 


.2781 


.2447 


.273 


.1442 


.3043 


.2679 


• *538 


.2234 


.2791 


.2456 


.274 


.1447 


•3054 


.2688 


•2547 


.2242 


.2801 


.2465 


.275 


.1452 


-3065 


.2698 


.2556 


.2250 


.2811 


■2473 


.276 


•1457 


.3076 


.2707 


-2565 


.2258 


.2821 


.2482 


.277 


.1462 


.3086 


.2717 


.2574 


.2266 


.2830 


.2490 


.278 


.1467 


•3097 


.2726 


-2583 


.2274 


.2840 


.2499 


.279 


•1473 


.3108 


.2736 


.2592 


.2282 


.2850 


.2508 


.280 


.1478 


-3"9 


.2745 


.2602 


.2290 


.2861 


.2517 


.281 


.1483 


■3^3° 


-2755 


.2611 


.2298 


.2871 


.2526 


.282 


.1488 


-3140 


.2764 


.2620 


.2306 


.2880 


•2534 


.283 


•1493 


.3151 


.2774 


.2629 


.2314 


.2890 


■2543 


.284 


.1498 


.3162 


.2783 


.2638 


.2322 


.2900 


•2552 


.285 


.1504 


•3173 


■2793 


.2647 


■2330 


.2910 


.2561 


.286 


.1509 


-3184 


.2802 


.2656 


-2338 


.2920 


.2570 


.287 


.1514 


-3194 


.2812 


.2665 


.2346 


• .2930 


.2578 


.288 


•I519 


-3205 


.2821 


.2674 


.2354 


.2940 


.2587 


.289 


.1524 


.3216 


.2831 


.2683 


.2362 


.2950 


.2596 


.290 


•1529 


•3227 


.2840 


.2693 


.2370 


.2960 


.2605 


.291 


.1535 


.3238 


.2850 


.2702 


.2378 


.2970 


.2614 


.292 


,1540 


.3248 


.2859 


.2711 


.2386 


. 2980 


.2622 


•293 


-1545 


•3259 


.2868 


.2720 


■2394 


.2990 


.2631 


.294 


•1550 


.3270 


.2878 


.2729 


.2402 


.3000 


.2640 


.29s 


-1555 


.3281 


.2887 


.2738 


.2410 


.3010 


.2649 


.296 


.1560 


.3292 


-2897 


•2747 


.2418 


.3020 


.2658 


.297 


.1566 


•3302 


.2906 


.2756 


.2426 


.3030 


.2666 


.298 


.1571 


.3313 


.2916 


.2765 


.2434 


.3040 


.2675 


.299 


-1576 


.3324 


•2925 


.2774 


.2442 


•3050 


.2684 


.300 


.1581 


•3335 


•2935 


.2784 


.2450 


.3060 


.2693 



304 



FOOD INSPECTION AND ANALYSIS. 



SEPARATION AND DETERMINATION OF THE VARIOUS CARBOHYDRATES 
OF CEREALS, ETC. STONE'S METHOD. 

Stone has thus tabulated the results of a series of analyses of various 
samples of wheat, flour, corn, and bread, in which he has separated the 
principal carbohydrates.* 



PERCENTAGES OF VARIOUS CARBOHYDRATES IN CERTAIN FOODSTUFFS. 



Crude 
Fiber. 

2.68 

2-51 
0.25 
0.25 

1-99 
1. 00 
2.70 
2.02 

0.34 
0.17 
2.22 



Whole wheat, I. . . 
Whole wheat, II. . 
Wheat flour, I. . . , 
Wheat flour, II. . . 

Corn 

Sugar-beet 

Bread (wheat, I). 
Bread (wheat, II). 
Bread (flour, I). . , 
Bread (flour, II). . 
Corn cake (maize) 



Sucrose. 


Invert 


Dextrin. 


Soluble 


Pento- 




Sugar. 




Starch. 


sans. 


0.52 


0.08 


0.27 


0.00 


4-54 


0.72 


0.00 


0.41 


0.00 


4-37 


0.18 


0.00 


0.90 


coo 


coo 


0.20 


0.00 


1.06 


coo 


0.00 


9.27 


COO 


0.32 


0.00 


5-14 


8.38 


0.07 


0.35 


coo 


4.89 


0.05 


0.32 


0.68 


1-37 


4.16 


0.06 


0.37 


0.23 


2.36 


4-34 


O.OI 


O.IO 


0.27 


1.99 


0.00 


o-iS 


0.38 


0.91 


1.74 


coo 


0.16 


0.19 


0.00 


2.80 


3-54 



Determination of Cane Sugar. — 100 grams of the finely ground ma- 
terial are extracted by boiling under a reflux condenser with 506 cc. of 
95% alcohol for three hours, the alcoholic extract is filtered, evaporated 
nearly to dryness, and then taken up with a small amount of water, to 
separate the sugar from the oils and waxes dissolved by the alcohol. This 
aqueous solution is invariably dextro-rotary, and seldom contains any 
reducing sugar. If the latter is present, it is determined in an aliquot 
part of the aqueous solution with Fehling's solution, the result being 
calculated to dextrose. The remainder of the aqueous sugar solution, or 
the whole of it, if, as is almost always the case, dextrose is absent, is 
then inverted by heating with hydrochloric acid in the usual manner 
(page 611) and the sugar is estimated with Fehling's solution, calcu- 
lating the result to sucrose (page 642). 

Determination of Dextrin. — Digest the residue from the above alco- 
holic extraction from eighteen to twenty-four hours with 500 cc. of cold 
distilled water, shaking frequently. On filtering, a clear solution is ob- 

♦ Jour. Am. Chem. Soc, 19, 1897, P- 183, and U. S. Dept. of Agric, Off. of Exp. Sta., 
Bui. 34. The percentages of normal starch found by Stone are obviously erroneous, and 
are for this reason excluded from the table as here given. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 305 

tained, which should be tested with iodine for soluble starch. If the 
latter is not found (which is nearly always the case), the solution is con- 
centrated to a small volume, avoiding a temperature higher than 80° to 
90°, and this is boiled under a reflux condenser for two hours with one- 
tenth its volume of hydrochloric acid (specific gravity 1.125). Deter- 
mine the dextrose by Fehhng's solution and calculate to dextrin by the 
factor 0.9. Or, instead of submitting the concentrated aqueous extract to 
hydrolysis as above, the dextrin may be roughly determined gravimetrically 
therein by treating with several volumes of strong alcohol until no further 
precipitation is produced. The flocculent precipitate thus obtained is 
collected, dried, and weighed. 

Determination of Starch. — Dry in an oven the residue from the pre- 
ceding treatment and determine its quantitative relation to the original 
sample ; 2 grams are then accurately weighed and subjected to the dias- 
tase method of starch determination (page 292). 

Determination of Pentosans and Hemicelluloses. — The washed resi- 
due, left after fikering off the starch-containing solution from the process 
of heating with malt extract in the preceding starch determination, is 
boiled for an hour with 100 cc. of 1% hydrochloric acid, which converts 
all the pentosans into sugar. Filter, and wash the residue thoroughly, 
make up the solution to 200 cc, and determine the sugar with Fehling's 
solution, calculating the resuks for xylan, assuming that the chief sugar 
formed is xylose. The reducing power of xylose is assumed to be 4.61 
milHgrams for each cubic centimeter of Fehling's solution. If the volu- 
metric Fehhng method is used, 10 cc. of Fehling's solution are thus 
equivalent to 0.046 gram xylose. Xylose X 0.88 = xylan. 

Crude Fiber {Cellulose, etc.). — The residue from the last dilute acid 
hydrolysis is boiled with 200 cc. of 1.25% solution of sodium hydroxide 
for half an hour, filtered, dried, and weighed. It is then ignited, and 
the weight of the ash deducted from the first weight. 

PROTEINS OF CEREALS AND VEGETABLES. 

Different cereal and vegetable foods present considerable variations 
in the character and extent of their protein constituents, and by no means 
all of the common vegetable foods have been studied in detail. 

Osborne, in connection with Voorhees and Chittenden, has made 
a careful study of the proteins of many of the cereals, of potatoes, and 
of peas. A brief outline only will be given in what follows of methods 



306 FOOD INSPECTION AND ANALYSIS. 

for separation of the vegetable proteins. For fuller details the reader 
is referred to the work of Osborne et al. in the American Chemical Journal, 
Vols. "" 14, and 15, and to the Journal of the American Chemical Society, 
Vols. 17, i8, [9, and 20. 

Proteins Soluble in Water and Dilute Salt Solution. — By the action 
of various solvents it is possible to separate the different classes of pro- 
teins for examination or analysis. Thus water at first applied extracts 
certain of the soluble proteins, as does a weak salt solution. Osborne 
and Voorhees recommend the use of a 10% solution of sodium chloride 
as the first solvent to apply for separating vegetable proteins, shaking 
the finely ground material with twice its weight of the salt solution. The 
salt solution, after filtering, is then subjected to dialysis, the protein matter 
thus separated out being a globulin, while that not precipitated on dialysis 
is assumed as the protein matter of the substance soluble in water. Two 
albumins and a proteose are found in wheat to be thus soluble in water. 
1\ the proteins soluble in salt solution are to have their total nitrogen 
determined, they are completely precipitated from the solution by satu- 
rating with zinc or ammonium sulphate. 

There are thus two classes of proteins soluble in 10% salt solution: 
(a) globulins, insoluble in water alone, and {h) albumins and proteoses, 
which are soluble in water. 

Separation of Albumins, Proteoses, and Globulins. — Starting with the 
aqueous solution containing the albumins and proteoses, if present, the 
former are best separated according to Osborne and Vorhees by fractional 
coagulation, effected by heating at different temperatures, those that 
precipitate out at a temperature under 65° being first filtered out, and 
the filtrate submitted to a higher temperature not. exceeding 85°. The 
two portions thus separated may be collected in filters, and their nitrogen 
separately determined. 

The proteose may be precipitated from the filtrate by saturating with 
ground salt, or by adding, first salt to the extent of 20%, and finally acetic 
acid. 

The globulins, precipitated in the original 10% salt solution by the 
process of dialysis as described, may themselves be separated by employing 
salt solution of varying strength as solvents.* 

Proteins Soluble in Dilute Alcohol, but Insoluble in Water. — The 
residue from the treatment with 10% sodium chloride is digested with 75% 
alcohol at about 46° C. for some time and filtered. The residue is further 

* Am. Chem. Jour., 13, p. 464. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 307 

digested at about 60° with 75% alcohol three separate times. The evapo- 
rated filtrates contain the alcohol-soluble proteins. In this class are the 
hordein of barley, the gliadin of wheat and rye, and the zein of corn. 

Proteins Insoluble in Water, Salt Solution, and Dilute Alcohol. — It is 
customary to determine the nitrogen in the final residue without further 
attempt to separate the remaining protein matter. It is, however, possi- 
ble to further extract with alkaline and acid solvents, if desired, which 
process, however, changes the nature of the proteins from that in 
which they originally exist in the substance. 

Character and Amount of Proteins in Wheat.*— The proteins of 
wheat, according to Osborne, are five in number, as follows: 

Amount Present, 
Per Cent. 

Soluble in water: / Albumin (leucosin) 0.3 to 0.4 

I Proteose 0.3 

Soluble in 10 per cent NaCl: Globulin (edestin) 0.6 to 0.7 

Soluble in dilute alcohol: Gliadin 425 

Insoluble in above: Glutenin 4 . 00 to 4 . 5 

The term gluten is applied to the protein content of wheat flour 
insoluble in water, the value of flour for baking bread depending on 
the amount present. Gluten contains the two definite proteins, gliadin 
and glutenin. Crude gluten, as obtained by washing the dough in the 
analytical process (page 331), is a complex mixture of many bodies, 
containing, besides the two proteins above named, small quantities of 
cellulose, mineral matter, lecithin, and starch. 

Separation and Determination of Wheat Proteins. — Teller's Method.f — 
Non-gluten Nitrogen. — Two grams of the finely divided sample are mixed 
with about 15 cc. of 1% salt solution in a 250-cc. flask. The flask is shaken 
at intervals of ten minutes during one hour, after which it is filled to the 
mark with the salt solution and allowed to stand two hours. The super- 
natant liquid is then filtered through a dry filter into a dry flask, leaving 
most of the solid material 'n the flask, passing the first part through twice, 
if necessary, for a clear filtrate. With a pipette, exactly 50 cc. of clear 
filtrate are run into a 500-cc. Kjeldahl digestion-flask, 20 cc. of the usual 
reagent sulphuric acid for the Gunning process (p. 58) are added, and 
the contents of the flask brought to a gentle boil. After the water has 

* Am. Chem. Jour. XV, 392-471; XVI, 524. 
t Ark. Exp. Sla. Bui. 42, p. 96. 



308 FOOD INSPECTION AND ANALYSIS. 

been driven off and the acid has stopped foaming, the potassium sul- 
phate is added and the digestion completed. From the per cent of 
nitrogen thus obtained 0.27% is deducLed, this figure corresponding to 
the amount of gliadin soluble in 1% salt solution under the above con- 
ditions. The remainder is the percentage of non-gluten nitrogen. 

Cduten Nitrogen. — This is obtained by difference between the total 
nitrogen and the non-gluten nitrogen as above obtained, or by deducting 
the combined nitrogen of the edestin, leucosin, and the amido-nitrogen 
from the total nitrogen. 

Edestin and Leuco:dn. — Edestin is a globulin belonging to the vegetable 
vitelHns, and is precipitated from salt solutions by dilution, or by satu- 
ration . with magnesium or ammonium sulphate, but not by saturating 
with sodium chloride. It is not coagulated below 100° C, but is partly 
precipitated by boiling. Leucosin is an albumin, coagulating at 52°, 
but precipitates from salt solution by saturating with sodium chloride 
or magnesium sulphate. 

To 50 cc. of the clear salt extract, obtained as described under non- 
gluten nitrogen, 250 cc. of pure 94% alcohol are added in a Kjeldahl 500-cc. 
digestion-flask, the contents thoroughly mixed, and allowed to stand 
over night. The precipitate is collected in a lo-cm. filter, which is 
returned to the flask and the nitrogen determined. This represents 
the nitrogen of the combined edestin and leucosin. These proteins 
may, however, be separated by coagulating the leucosin at 60°, and pre- 
cipitating the edestin by adding alcohol to 50 cc. of the clear filtrate, 
determining the nitrogen separately in each precipitate. 

Amido-nitrogen. — Allantoin, asparagin, cholin, and betaine are nitrog 
enous bases present in wheat. 

Ten cc. of a 10% solution of pure phosphotungstic acid are added 
to 100 cc. of the clear salt extract as above obtained, thus precipitating 
all the proteins, which are allowed to settle preferably over night. Fil- 
ter, and determine the nitrogen in the clear filtrate. The filtrate 
should be tested with a little of the phosphotungstic acid reagent to 
make sure that all the proteins have been separated. In some 
cases, as in bran for instance, more than 10 cc. of the reagent are 
necessary. 

Gliadin is dissolved most readily from flour by hot dilute alcohol, 
but is entirely insoluble in absolute alcohol. One gram of the mate- 
rial is extracted with 100 cc. of hot 75% alcohol, by shaking the mixture 
thoroughly in a flask, and heating for an hour at a temperature just below 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 309 

the boiling-point of alcohol, with occasional shaking. After standing 
for an hour, the hot liquid is decanted upon a lo-cm. fiher, and 25 cc. 
of the hot alcohol are added to the residue and shaken, after which the 
residue is again allowed to settle, and the liquid decanted. This is 
repeated six times. The remainder of the alcohol is then driven off 
by evaporation, and the nitrogen determined in the residue. The 
difference between the total nitrogen and the nitrogen thus obtained, 
gives the nitrogen of the alcoholic extract, which includes the amides. 
Subtracting the latter, or amido-nitrogen, the remainder is the gliadin 
nitrogen. 

Glutenin Nitrogen.— This is the difference between the gluten nitro- 
gen and the gliadin nitrogen. 

The factor by which the nitrogen should be multiplied in determin- 
ing the various proteins, according to Osborne and Voorhees, is 5.7 for 
wheat. 

Proteins of the Common Cereals and Vegetables.— Osborne and his 
coworkers have made a detailed study of the protein constituents not 
only of wheat as above outlined, but of other common grains and vegeta- 
bles, and the results of these investigations may be thus briefly sum- 
marized : 
Proteins of rye:* 

Insoluble in salt solution ^^^ ^"** 

Soluble in alcohol, gliadin ]\\ ^-44 

Soluble in water, leucosin 

Soluble in salt solution: (f^l 'zzz:::::::::::;::::;:^^^ 

8.63 

Proteins of barley:! 

( T »,.-. c- 1 Per Cent. 

Soluble in water: \ Leucosin 

/ rroteose \ 0.3 

Soluble in salt solution, edestin 

Soluble in dilute alcohol, hordein !!!!!!!!!!! ^ '^^ 

Insoluble in water, salt solution, and alcohol 4" ro 

Proteins of corn:| 

Soluble in water: Proteose ^ 

^ , ,, ( Very soluble globulin ...[ o" . 

Soluble in salt solution : < Maysin. ^ 

i Edestin ' ^^ 

Soluble in dilute alcohol: Zein 

Insoluble in above, but soluble in two-tenths "per cent potash "solution. .' .' .' ." .' ," .* ." .' 3 .' 15 
Protein of pea:§ 

Soluble in sah solution: Globulins] Lfgumin ^^^^ 

Soluble in water: Albumin, legumelin, proteose.'.'.*.','.'. '. '. '. '. '. '. '. '. *.'.'.' .' ^'°° 



* Jour. Am. Chem. Soc, 17, page 429. f Ibid., 17, p, 539 

t Ibid., 19, p. 525. 5 Ibid, 18. p. 583; 20, pp. 348 and 410. 



310 



FOOD INSPECTION AND ANALYSIS. 



MINERAL CONSTITUENTS OF CEREALS AND VEGETABLES. 

The food analyst often finds the determination of one or more of the 
mineral constituents of a food product of value as a means of detecting 
adulteration, since the addition of foreign material may alter materially 
the composition of the ash. 

The following table * shows the composition of the pure ash of common 
cereals. 

COMPOSITION OF ASH OF CEREALS. 



K2O. 



NaaO. 



CaO. 



MgO. 



Fe203. 



P2O0 



SO3. 



CI. 



Si02. 



Wheat (Canada) 

Rye (Minnesota) 

Barley (U. S.) 

Oats (U. S.) 

Corn (U. S.) 

Rice, polished (Guatemala) 
Buckwheat (U. S.) 



24 03 

27 
24 



35 



15 



9 55 
4.64 
6.42 

438 

7.72 

13.98 

2. 26 



3-50 
5.56 
2.44 
4.09 
3.18 
4.48 
6.62 



13 24 

11-73 
8.23 
7.18 

17.99 
9.60 

20.55 



0.52 
5- 23 

0-33 
o. 20 
0.50 



46.87 
41.81 

35-47 
24-34 
35-25 
43-21 
24.09 



O.OI 

0.52 

0.22 

0.48 
0.44 

0.24 
3-59 



0.00 
0.58 
0.56 
1 .02 
0.00 
0.80 
0.67 



2.28 

2-45 
22.30 
42,64 
1 .00 
6. 14 
5-54 



Snyder t obtained the following average results in the analysis of 
the ash of 12 samples of wheat: 

Potash (K2O) 30-2% 

Soda (NaaO) 0.7 

Lime (CaO) 3.5 

Magnesia (MgO) 13.2 

Ferric oxide (Fe203) 0.6 

Phosphoric acid (P2O5) 47-9 

Sulphuric acid (SO3) o.i 

Silica (Si02) 0.7 

Chlorine (CI) 0.2 



The average amount of ash in the grain was 2.0 



07 
/o- 



Konig gives the following analyses of the ash of various leguminous 
and other vegetables : 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 13, part 9, p. 1212. 
t Minn. Agric. E.\p. Sta., Bui. 29, 1893, p. 149. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



311 



Beans. . . 
Peas. . . . 
Potatoes . 
Beets . . . 
Carrots. . 
Turnips . 



*4-l tfl 


>>S 


















o oj 










.2 


TD 










jD ca 


.S^ 


ji: 






<u 





U-H 


^•"2 




2; 


< 


n! 

Oh 


n) 

•a 



E 
3 


nl 





1^ 







IS 


3-57 


42.49 


1-34 


4-73 


7.08 


0.57 


38-74 


2-53 


0-73 


29 


2-73 


41 -79 


0.96 


4-99 


7.96 


0.86 


36 -43 


3-49 


0.86 


53 


3-77 


60.37 


2.62 


2-57 


4.69 


I 18 


17-33 


6.49 


2.13 


15 


6.44 


54 02 


15-90 


4.12 


4-54 


0.82 


8.4s 


3-17 


2.38 


II 


5-58 


35-21 


22.07 


II .42 


4-73 


I -03 


12.46 


6.72 


2.47 


32 


8.01 


45 40 


9.84 


10.60 


3-69 


0.81 


12.71 


II. 19 


1.87 



o 



1-57 
1-54 
3-II 

8.40 

5-13 
S-oi 



Scheme for Complete Ash Analysis. — The following scheme in essen- 
tial details was suggested by the later Prof. S. L. Penfield of Yale Uni- 
versity for use at the Connecticut Agricultural Experiment Station. 

Preparation of Ash. — The amount of material which should be re- 
duced to ash depends on the percentage of total ash present and the 
amount of material available. Usually 100 grams is a suitable amount; 
if, however, the material (e.g., tobacco) is rich in ash, 50 grams is suffi- 
cient, while if it contains but a small amount of ash, 200 grams or even 
more may be required. About 5 grams of ash is a liberal amount for a 
complete analysis, but in case of necessity i gram will suffice if care is 
taken to so adapt the scheme as to make as many determinations as pos- 
sible on one weighed portion. 

The ashing is carried on in a platinum dish heated below redness 
by a Bunsen burner. In order to distribute the heat and prevent over- 
heating, a piece of asbestos paper is introduced between the dish and the 
flame. The material first chars, then begins to glow just below the 
surface, and the combustion gradually extends downward until it reaches 
the bottom of the dish. Then, and not until then, the unburned carbon 
on the surface should be stirred in with the ash to facilitate burning. 
Care should be taken not to heat higher than dull redness, thus avoiding 
the loss of alkali chlorides and the fusion of alkali phosphates about 
the particles of carbon. A muffle furnace may be used to complete the 
burning. 

Substances rich in starch or sugar are most difficult of combustion, 
as the charcoal forms a hard mass, while substances rich in fibrous or 
woody matter burn quite readily without losing their powdered con- 
dition. A certain amount of unburned carbon is no disadvantage, as 
it is determined in the course of the analysis. 



312 FOOD INSPECTION AND ANALYSIS 

Finally cool the ash, grind to a powder, mix without loss, and weigh, 
thus determining the percentage of crude ash. 

Determination of Water. — Heat i gram of the ash in a platinum 
crucible well below redness to constant weight. 

Determination of Carbonic Acid. — Determine carbonic acid as 
described on p. 353 using the portion dried for the determination of 
water. 

Determination of Charcoal and Sand. — Weigh i gram of the ash, 
or transfer the solution and residue from the determination of carbonic 
acid, into a beaker, add 25 cc. of water and 25 cc. of 10 per cent hydro- 
chloric acid, and boil gently for 10 minutes. Filter on a Gooch crucible, 
and wash thoroughly with hot water. Reserve the filtrate for determina- 
tion of silica, iron oxide, alumina, lime, and magnesia. Wash the residue 
on the crucible once with alcohol and once with ether, and dry to 
constant weight at 100° C. Ignite and weigh again. The loss on 
ignition is the charcoal, the residue is sand. 

Determination of Silica, Iron Oxide, Alumina, Lime and Magnesia. — 
Evaporate to dryness in a platinum dish the filtrate from the determina- 
tion of charcoal and sand, heat for some hours on the water bath, and 
dry at 130° C. until all hydrochloric acid is removed. Moisten the 
residue thoroughly with concentrated hydrochloric acid, add hot water, 
stir, and decant the solution on an ashless filter. Treat the residue 
again with acid and hot water, and repeat the treatment until nothing 
but sihca remains undissolved. Finally collect the silica on the paper, 
wash with hot water, ignite in a platinum crucible, and weigh. 

To the filtrate add ammonia until a precipitate forms which remains 
on stirring, and then add sufficient hydrochloric acid to just dissolve the 
precipitate. Heat to 50° C. and add an excess of ammonium acetate 
solution and 4 cc. of 80 per cent acetic acid. Digest at 50° C. until 
the mixed phosphates of iron and alumina have settled, filter, wash with 
hot water, ignite in a platinum crucible, and weigh. As the precipitate 
is usually slight and consists almost entirely of iron phosphate, the 
iron oxide may be calculated with reasonable accuracy using the 
factor 0.53. If, however, greater accuracy is desired fuse the weighed 
precipitate with 10 parts of sodium carbonate, dissolve in dilute sul- 
phuric acid, reduce with hydrogen sulphide, determine iron by the vol- 
umetric permanganate method, and in the same solution determine phos- 
phoric acid by the molybdic method. The alumina is obtained by 
difference, subtracting the sum of the weights of the oxide of iron and 
phosphoric acid from the total weight of the precipitate. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 313 

To the filtrate from the mixed phosphates add an excess of ammo- 
nium oxalate, allow to stand in a warm place over night, filter, ignite 
the precipitate in a platinum crucible over a Bunsen burner, and finally 
to constant weight over a blast lamp, thus obtaining the calcium oxide. 

Precipitate the magnesia in the filtrate from the lime by adding 
ammonia to alkaline reaction, then an excess of sodium phosphate solu- 
tion with constant stirring, and finally sufficient concentrated ammonia 
to form one-tenth the final volume. Let stand over night, collect the 
magnesium ammonium phosphate on a Gooch crucible, ignite to mag- 
nesium pyrophosphate, and weigh. 

Determination of Sulphuric Acid, Potash, and Soda. — Boil i gram 
of the ash with dilute hydrochloric acid, and remove charcoal, sand, and 
silica, as described in the preceding section. Evaporate nearly to dryness 
to remove the excess of acid. Dilute to loo cc, heat to boiling, and add 
barium chloride solution drop by drop until the sulphuric acid is pre- 
cipitated. Allow to stand over night, filter, ignite, and weigh as 
BaS04. 

Heat the filtrate to boiling, add enough barium hydroxide to make 
the solution strongly alkaline, filter, and proceed with the determina- 
tion of potash and soda, as described on p. 361. 

Determination of Phosphoric Acid. — Dissolve 0.5 gram of the ash 
in hydrochloric acid, filter, and wash. Neutralize with ammonia, clear 
with nitric acid, and proceed as described on p. 362. 

Determination of Chlorine. — Dissolve i gram of the ash in cold, very 
dilute nitric acid, filter, and wash. To the filtrate add an excess of 
silver nitrate, and heat nearly to boiling with constant stirring. Filter 
on a Gooch crucible, wash with hot water, dry the precipitate at a low 
heat, and heat cautiously at dull redness until the silver chloride has 
partially melted. 

If desired the chlorine may be determined volumetrically by Vol- 
hard's method, as follows: To the nitric acid solution add a known 
volume of decinormal silver nitrate solution sufficient to precipitate the 
chlorine, and 5 cc. of saturated solution of ferric alum. Titrate with 
decinormal ammonium thiocyanate solution until a permanent brown 
color is formed. Subtract the volume required from the volume of 
decinormal silver nitrate added, and calculate the chlorine. 

Determination of Sulphvir in Vegetable Materials.* — Place from 1.5 
to 2.5 grams of material in a nickel crucible of about ico cc. capacity 

*A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), pp. 23, 24. 



314 FOOD INSPECTION AND ANALYSIS. 

and moisten with approximately 2 cc. of water. Mix thoroughly, using 
a nickel or platinum rod. Add 5 grams of pure anhydrous sodium 
carbonate, and mix. Add pure sodium peroxide, small amounts (approx- 
mately 0.50 gram) at a time, thoroughly mixing the charge after each 
addition. Continue adding the peroxide until the mixture becomes 
nearly dry and quite granular, requiring usually about 5 grams of 
peroxide. Place the crucible over a low alcohol flame (or other flame 
free from sulphur), and carefully heat with occasional stirring until 
contents are fused. (Should the material ignite the determination is 
worthless.) After fusion, remove the crucible, allow to cool somewhat, 
and cover the hardened mass with peroxide to a depth of about 0.5 cm. 
Heat gradually, and finally with full flame until complete fusion takes 
place, rotating the crucible from time to time in order to bring any 
particles adhering to the sides into contact with the oxidizing material. 
Allow to remain over the lamp for ten minutes after fusion is complete. 
Cool somewhat. Place warm crucible and contents in a 600 cc. beaker, 
and carefully add about 100 cc. of water. After violent action has ceased, 
wash material out of crucible, make slightly acid with hydrochloric acid 
(adding small portions at a time), transfer to a 500 cc. flask, cool, and 
make to volume. Filter, and take a 200 cc. aliquot for determination 
of sulphates by precipitating with barium chloride in the usual manner. 
Determination of Chlorine in Vegetable Substances.* — Impreg- 
nate 5 grams of substance in a platinum dish with 20 cc. of a 5 per cent 
solution of sodium carbonate, evaporate to dryness, and ignite as 
thoroughly as possible. Extract the residue with hot water, filter, and 
wash. Return to the platinum dish, ignite to an ash, dissolve in nitric 
acid, and determine chlorine by the Volhard method (p. 313). 

MICROSCOPY OF CEREAL PRODUCTS. 

The histology of the cereals is more fully considered in the works on 
food microscopy, the brief descriptions here given should, however, enable 
the food chemist to identify the commoner products. The tissues of the 
various cereals are quite distinctive, serving usually to determine the 
particular grain from which a given product is made. -In the case of 
flour the tissues are largely removed in milling, the fragments remaining 
being small and few in number. Such products are identified either by 

* A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), pp. 23, 24. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



315 



the character of the starch grains — as in the detection of wheat or corn 
flour in buckwheat flour — or else, if the starch is not sufficiently char- 
acteristic — as in the detection of wheat flour in rye flour — by examining 
the tissues from a considerable amount of the material. 

The most convenient method of accumulating the tissues from flour 
is to mix thoroughly 2 grams of the material with 200 cc. of water and 3 cc. 




Fic. 62.— Wheat. Elements in Surface View. X160. (WiNTON.) 

epi^ epicarp at end of grain, with / hairs; epi^ epicarp on body of grain; hy hypoderm 
(first layer of mesocarp); in intermediate cells; tr cross cells; lii^ typical tube cells; tu'^ tube 
cells passing into spongy parenchyma; outer layer of spermoderm; i inner layer of sperm- 
oderm; P perisperm; al aleurone cells; am starch grains. 



of sulphuric acid, bring to a boil, allow to settle, and carefully decant ofiE 
the liquid from the deposit of tissues. The tissues are mounted for 
examination in very dilute sodium hydroxide solution. 

Wheat Products. — Fig. 62 and PI. VIII show the principal elements 
of the wheat kernel. 

The outer layer or epicarp (Fig. 62, epi'^ and epi^) consists of beaded 



316 FOOD INSPECTION AND ANALYSIS. 

cells, which on the body of the kernel are elongated, but at the end are 
polygonal. From this layer at the end of the kernel arise the hairs (Fig. 
62, /; PI. VIII, Fig. 151) which form a beard clearly visible under a lens. 
Some of these hairs become detached in milling, and pass endwise through 
the bolts, hence their presence in even the highest grade of flour. The 
second" layer or hypoderm (hy) resembles the first, while the third, 
although likewise made up of beaded cells, is strikingly different and 
forms the most characteristic tissue of the grain. These cells (Fig, 62, 
ir; PL VIII, Fig. 150) being transversely extended are known as "cross 
cells,'' and are further distinguished from the outer layers by their ar- 
rangement side by side in rows. The cells of the intermediate layer (Fig. 
62, in) and the tube cells (tu^ and tu^), although of striking appearance, 
are not of as frequent occurrence as the other layers. The crossing 
layers of the seed coat or spermoderm {i and 0), are often met with, 
and are characterized by the thin walls of the cells and their brownish 
color. 

The peris perm (P), consisting of colorless cells, is seldom seen, except 
after special preparation, while the next layer, made of up aleurone cells 
(Fig. 62, al; PI. VIII, Fig. 150), is the most conspicuous of the kernel. 
This layer is not, however, characteristic of wheat, as it is found in all 
cereal grains and in buckwheat. The aleurone cells do not contain, as 
was formerly supposed, the gluten of the grain; this occurs with the 
starch in the thin-walled cells within the aleurone layer. 

The starch granules (Fig. 62, am\ PI. VIII, Fig. 152) are described 
on page 289. The starch cells and the aleurone cells together form the 
endosperm. 

The germ, situated at one side of the lower end of the kernel, is made 
up of very small cells containing fat and protein, but no starch. 

Rye Products.— The structure of rye (Fig. 63; PI. VII) resembles 
closely that of wheat. The number and general characters of the cell 
layers are the same in both, and the starch granules are very much alike. 
There are, however, certain points of difference which serve to dis- 
tinguish the products of the two cereals, and even to detect the presence 
of a wheat product in a rye product, and vice versa: 

First. The breadth of the cavities of wheat hairs is usually less than 
the thickness of the walls, whereas in rye hairs the reverse is often true 
(Figs. 62 and 63, /). 

Second. The cross cells of wheat have rather thick, distinctly beaded 
side walls, and thin, pointed end walls; the cross cells of rye have rather 



CEREALS, VEGETABLES. FRUITS, AND NUTS. 



317 



thin, indistinctly beaded side walls, and usually swollen, rounded end 
walls (Figs. 62 and 63, tr; Figs. 150 and 146). 

Third. The large starch granules of wheat seldom reach 0.050 mm. 
in diameter, while those of rye frequently exceed that limit. Radiating 
clefts often occur in the starch granules of rye (PI. VII, Fig. 148). 




Fig. 63. — Rye, Outer Bran Layers in Surface View. Epicarp consists of porous cells with t 
hairs, and z; hair scars; /r cross cells. X160. (Moeller.) 



Fourth. Wheat flour yields a considerable amount of gluten when 
treated according to Bamihl's test (page 336); rye flour yields none or 
only a trace. 

Barley Products. — The common varieties of barley are " chaffy," 
that is, the grain after threshing is still closely invested by the chaff 
(PI. I, Fig. 123). The grain within the chaff is analogous in structure 
to wheat and rye, but differs from these in that the cross cells are not 
beaded and form a double layer (Fig. 64, tr), and the starch granules 
seldom exceed 0.035 "^"^- '^^ diameter (PI. I, Fig. 124). The starch is 
more fully described on page 290. 

Com Products. — The most characteristic element of corn is the 
starch (page 290; PL IV). Polygonal starch granules 0.017 to 0.030 
mm. in diameter occur in no other vegetable product of economic im- 
portance, excepting the seeds of Kaffir corn and other grains belonging 
to the genus Sorghum, which are used chiefly for cattle or poultry foods. 



318 



FOOD INSPECTION AND ANALYSIS. 



Oat Products. — The oat kernel resembles barley in appearance, 
but is net ribbed. In the preparation of oat meal and other breakfast 




Fig. 64. — Barley. Surface view of tr double layer of cross-cell; tii tube cells; ic seed coat. 

X300. (MOELLER.) 

foods, the chaff (PI. IV, Fig. 135; PI. V, Fig. 137) is removed and 
utilized as a cattle food. The elements of the grain of chief value in 



mes 




Fig. 65. — Rice. Bran coats in surface view, epi epicarp; mes mesocarp; Ir cross cells; 
tu tube cells; 5 seed coat; N perisperm. X300. (Winton.) 

identification are the hairs and the starch granules. The hairs (PL V, 
Fig. 138) are much longer than those of wheat, r}'e, and barley, often 
reaching i mm. They taper toward both ends, so that when detached 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



319 



they often appear to be pointed at the base as well as at the apex. The 
starcli granules are small, of the polygonal type, and often occur in egg- 
shaped aggregates (page 291; PI. V, Fig. 139). 

Rice Products. — The chaff which envelops this grain is rough and 
silicious, and after removal from the inner kernel is not suited even for 
cattle food. Its appearance under the microscope is shown in Plate VI, 
Fig. 142. The thin skin of the kernel proper is largely but not entirely 




Fig. 66. — Buckwheat. Bran coats in surface view. Seed coat consists of outer epidermis, 
m spongy parenchyma, and cp inner epidermis; al aleurone cell. X300. (Moeller.) 



removed in the preparation of rice for the market. The elements of this 
skin are shown in Fig. 65, the outer layer {epi) being the most char- 
acteristic. Unlike wheat, rye, and barley, it has no beard. Rice starch 
(PI. VI, Fig. 143') is hardly distinguishable from oat starch. It is 
described on page 291. 

Buckwheat Products. — In the preparation of buckwheat flour the 
black outer hulls and the inner skin or bran are largely, but not com- 
pletely, removed. The bran elements are characteristic constituents of 
the flour, and are rendered especially distinct by adding a drop of dilute 
potassium hydroxide solution to a water mount (Fig. 66). The cells 
with wavy walls (0) and the spongy parenchyma (m) are especially 
noticeable. The starch of buckwheat resembles that of oats, but the 
individual granules are somewhat larger and occur in rod-shaped, not 
egg-shaped, aggregates (page 290; PI. II, Fig, 128). Ma.sses of starch 



320 



FOOD INSPECTION AND ANALYSIS. 



granules (PI. Ill, Fig. 129) conforming to the shape of the cells, occur 
in abundance in the flour. 

FLOUR. 

Flour is the term applied to the finel)' ground and bolted substance 
of wheat and other grains, though, unless otherwise qualified, by the 
term "flour" is generally undertsood that of wheat. 

Graham flour is an unbolted meal prepared from the whole wheat 
kernel. 

Process of Milling. — The crude milling process which prevailed until 
the last quarter of the nineteenth century consisted in grinding the wheat 
between millstones and bolting to remove the bran and shorts. In the 
modern or Hungarian process the wheat is first crushed between cor- 
rugated rollers, then by sifting separated into middlings, break flour, and 
bran. The middlings, consisting of the hard glutinous portions of the 
grain in granular form, are gradually reduced to fine flour between smooth 
rollers and freed from impurities by means of a series of bolts. A number 
of grades of flour are thus produced, the streams of which are so combined 
with each other and the break flour as to form the finished products. 

The Grades of Flour commonly made are (i) patent, forming 85% 
or less of the flour output; (2) clear or bakers', an intermediate grade 
inferior to the patent in color and rising properties; and (3) low grade 
or "red dog,'' about 5%, suitable only for caltle food. Some mills make 
two or more grades of patent and clear. On the other hand, it is a frequent 
practice to combine all the flour streams other than of low grade to form 
a straight. 

The By-products are (i) hran, the outer coatings of the grain in 
flakes, (2) shorts, the finer offal containing both starchy matter and bran 
elements, and (3) germ, rich in oil, often run in with the bran. 

Composition of Wheat Flour and By-products.— The following analyses 
by Clifford Richardson* represent the products of the same milling: 





Mois- 
ture. 


Protein 
NX5.7 


Moist 
Gluten. 


Dry 

Gluten. 


Ether 
Ex- 
tract 
(Fat). 


Nitro- 
gen-free 
Extract 
(Starch, 
etc). 


Crude 
Fiber. 


Ash. 


Phos- 
phoric 
Acid. 


Fuel 
Value 

per 
Pound, 

Gal. 


Wheat (Spring).. . 

Patent flour 

Clear flour 

Low-grade flour . . 
Shorts 


9.07 
11.48 
12.18 
12.01 
10.94 
10.91 


12.93 
II. 81 
I3S7 
16.37 
15-32 
14.84 


36 14 
51-51 
10.01 


10.85 

16.97 

4.26 


2.74 
1-45 
2.00 
3-86 
4.67 
5-03 


71-77 
74-69 
71.30 
64.84 
61.76 
57-65 


1.70 
0.18 
0.33 
0-93 
3-90 
5-98 


1.79 

0.39 
0.62 
1.99 
3-41 
5-59 


0.82 
0.18 

0.31 
1. 16 
1.62 

2.78 


1723 
1673 
1669 
1691 
^703 


Bran 


1672 







= U. S. Dept. of Agric, Bui. 4, 1884, p. 38. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 321 

From the above it appears that the fat, fiber, ash, and phosphoric acid 
increase through the series, being least in the patent flour and greatest 
in the bran, while the nitrogen-free extract decreases. Considering only 
the flour, the protein is least in the patent and greatest in the low grade, 
but the gluten, although greater in the clear than in the patent, drops 
down sharply in the low grade. 

The ash of flour is a valuable index of grade. In a true patent it 
should not exceed 0.45%. In analyses of the ash of wheat and its prod- 
ucts and by-products Teller* found 48.05%, 49.32%, and 53.10% of 
phosphoric acid in patent, straight, and low grade flour respectively, as 
compared with 52.14% and 52.18% in the corresponding wheat and 
bran. In the ash of patent flour Teller found 38.50% of potash, 5.59% 
of lime, and 4.39% of magnesia, as compared with 29.70%, 3.10%, and 
13.23% respectively in the wheat. He found 0.24%, 0.27%, and 0.04% 
of zinc oxide in wheat, bran, and straight flour respectively, but reports 
none in patent and low grade flour. Other analysts have failed to con- 
firm the presence of zinc oxide in wheat or wheat products. 

As first pointed out by Snyder,! the acidity is also an index of grade. 
This is illustrated by the figures in the table on page 322. Although usually 
calculated as lactic acid, which acid is doubtless present in slight amount 
on aging and in larger amount after spoilage, the acidity is largely 
due to other substances. Swanson,t reasoning from the relation between 
acidity, amino compounds, and phosphorus and the apparent relation 
between acidity and ash, believes the acidity to be due in part to mono- 
potassium phosphate and amino compounds. 

Hard Wheats, such as the Spring varieties of the Northwest and 
Turkey red Winter wheat of Kansas, yield a " strong " flour rich in 
protein and gluten, the latter being of good tenacity, while Soft Wheats, 
such as are grown in states adjoining the Ohio River, yield a white 
starchy flour, the gluten being smaller in amount and lacking in tenacity. 

Analyses of typical hard and soft wheat flour freshly ground are given 
in the table on top of page 322. The percentages are of the total flour, 
excluding the low grade. Color values are given on page 326. 

Color of Flour. — The time-honored test for grade is by the color. 
A patent is practically free from bran specks while a clear contains 
such specks in noticeable amount. Both grades have a yellowish tint 
due to the color associated with the fat, which is more or less pronounced, 

* Ark. Agric. Exp. Sta., Bui. 42. 

t Jour. Ind. Eng. Chem., 4, 1Q12, p. 274. 



322 



FOOD INSPECTION AND ANALYSIS. 



Minnesota. 
Hard Spring. 



78% 
Patent. 



Nebraska. 
Hard Winter. 



80% 
Patent. 



20% 
Clear. 



Michigan. 
Soft Winter. 



80% 
Patent. 



20% 
Clear. 



Missouri. 
Soft Winter. 



40% 
Patent. 



60% 
Clear. 



Moisture 

Ash 

Crude fiber 

Protein (NX's-y) 

Alcohol sol. protein .. . 

Salt sol. protein 

Moist gluten 

Dry gluten 

Nitrogen-free extract. . 

Fat 

Acidity as lactic 



13-74 
0.44 
0.06 

10.60 

5-84 
1.62 

36-93 

12.48 

74.07 

1.09 

C.108 



13.26 

0.85 

0.26 

11.74 

6.21 

2.19 

38,76 

13-41 

71.91 

1.98 

0.230 



13-33 
0-39 
0.18 

11.09 

5-79 

1.48 

30.48 

9-85 
75-16 
0.85 
0.081 



12.85 
0.67 
0.24 

11.86 

6.55 

2.02 

42.50 

13.08 

73.06 

1.32 

0.158 



13.22 
0.42 
0.19 
8.66 
5-24 
1-45 

20.23 

6.97 

76.40 

I. II 

O.IIO 



12.62 

0.89 

0.27 

12.26 

5-53 

2.19 

31.24 

10-55 
72.19 

1-77 
0.250 



12.27 
0-39 
0.34 
9.01 

5-04 

1-25 

17.90 

5-9° 
77.12 
0.87 
0.063 



12.02 
0.50 
0.38 

10.72 
6.21 

1-43 
33-21 
10.22 

75-23 
1-15 
0.095 



according to the kind of wheat, but is not proportional to the per cent 
of fat. This is measured by the gasoHne color value (pp. 326 and 327). 

Graham and Whole Wheat Flour. — Graham flour, so named because 
of its early advocate, Dr. Graham, is the meal obtained by grinding the 
whole wheat kernel. Entire wheat flour, etomologically, should be a 
synonym for .Graham flour, but by trade usage has come to mean the 
ground wheat after removal of the bran. The following analyses by 
Snyder * show the composition of a sample of Oklahoma wheat, also 
the Graham, entire wheat, and straight flour made therefrom : 





Water. 


Protein 
NXS-7 


Fat. 


Total 
Carbohy- 
drates. 


Ash. 


Fuel 
Value, 

per 
Pound, 
Calories. 


Grain 

Graham flour 


8.65 

7-73 
7.46 

9-93 


15 -33 
15-33 
15.16 

13-74 


1.83 
1.79 
1.64 
0.92 


72.87 
73-83 
7452 
74.89 


1.32 
1.32 

1.22 
0.52 ■ 


4160 
4196 
4201 


Entire wheat flour 


Straight grade flour 


4065 





So-called Graham and whole wheat flour are too often various mixtures 
of the by-products of milling. 

In distinguishing imitation from Graham flour, valuable indications 
are furnished by comparing the analysis with that of whole wheat. After 
removal of the flour from the grain by the ordinary process of milling, 
no combination of the by-products can have the same analysis as that 
of the wheat. 



* U. S. Dept. of Agric, Off. of Exp. Sta., Bui. 156, 1905. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



323 



Le Clerc and Jacobs * have attempted to distinguish genuine from 
imitation Graham flour by determining the percentages of flour, fine 
middhngs, coarse middlings, shorts, and bran obtained by sifting and 
by determining in each portion total and alcohol-soluble nitrogen, and 
gliadin ratio, also in many cases by determining in addition ash, fiber, 
and pentosans (but not fat and nitrogen-free extract) in the unseparated 
sample and the flour. 

Flour of Other Cereals. — The following analyses are from Bulletin 
13, Part 9, of the Bureau of Chemistry: 



No. of 
Analyses. 



Moisture. 



Protein 
NX6.2S. 



Ether 

Extract 

(Fat). 



Nitrogen- 
free Ex- 
tract 
(Starch, 
etc.). 



Crude 
Fiber. 



Ash. 



Calcu- 
lated 
Calories 
of Com- 
bustion. 



Corn flour 

Rye flour 

Barley flour , 

Buckwheat flour 



12.57 
II. 41 
10.92 
11.80 



7-13 

13-56 

7-50 

8.75 



1-33 
1-97 
0.89 
1.58 



78.36 

73-37 
80.50 

75-41 



0.87 
1.86 
0.67 
0.52 



0.61 

1-55 



38.37 



38-54 



Damaged Flour. — Grain is often damaged by the growth of smuts, 
rusts, and ergot. Both grain and flour are also liable to attacks of molds, 
yeasts, algae, and bacteria. 

Various insects and other forms of animal life frequently infest grain 
or flour. Among these are weevils and various other beetles, flour moths, 
mites, and the wheat worm, a nematode related to trichina. 

Grain may also be damaged by sprouting, the diastase thus formed 
partially dissolving the starch granules with the formation of fissures 
and branching channels, readily seen under the microscope. Flour thus 
damaged is high in cold-water extract (p. s;^s)- 

Experiments by Olsen f and Swanson, Fitz, and Dunton, f indicate 
that the injury to the flour resulting from sprouting of the grain is not so 
great as was formerly supposed. The former found that while loaves 
made entirely from the flour of sprouted wheat were sticky, sweet, and 
spongy, addition of 10 % of sprouted to sound flour gave larger and better 
loaves, and the latter investi^ors found that the addition of flour from 
sprouted grain to sound flour produced little or no injurious effects. 

Ergot. — Ergot, a fungous growth containing a poisonous alkaloid, 
sometimes develops in rye and, less often, in wheat. Under the micro- 

* U. S. Dept. of Agric, Bur. of Chem., Bui, 164, 1913. 

t Amer. Food Jour., 6, 191 1, p. 36. 

t Kan. Agric. Exp. Sta., Tech. Bui. i, 1916. 



324 



FOOD INSPECTION AND ANALYSIS. 



scope it appears as a fine network of mostly colorless parenchyma cells, 
containing globules of fat (Fig. 67). Some of the cells are circular, 
others considerably elongated, and some contain a deep-brown coloring 
matter, which, with ammonia, become violet-red, changing to red with 
acid. Occasionally the cell walls appear of a dark color. If flour con- 
taining ergot be treated with a very dilute solution of anilin violet, the 
stain will be practically absorbed by the damaged particles of the grain, 
and resisted by the normal granules. A hot, alcoholic extract of flour 
containing ergot is colored red when treated with dilute sulphuric acid. 




^^^ 




A B 

Fig. 67. — A, Transverse Section of the Ergot of Wheat under the Microscope; B, Powdered 
"Wheat Ergot. (After ViUiers and Collin.) 



Adulteration of Flour. — Besides the substitution of cheaper or in- 
ferior grades for those of higher quality, the fraudulent admixture of 
corn flour to wheat flour was at one time extensively practiced. This 
adulterant is best detected by the microscope (p. 317). 

Rye flour has been adulterated with cheap grades of wheat flour or 
middlings. These admixtures are detected by the Bamihl test (p. 336) 
and by microscopic examination of the residue after boiling with dilute 
acid (page 315), noting especially the cross cells. 

Much of the so-called buckwheat flour formerly contained large amounts 
of wheat or corn flour, or both. Rice flour is also used in pancake flours, 
although probably not to cheapen the product. Self-raising pancake 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 325 

flours are usually mixtures of two or more flours with leavening material. 
The microscopic characteristics of the starch grains and tissues serve to 
identify the different flours present in such mixtures. 

In England so-called " improvers," notably calcium acid phosphate 
and other soluble phosphates and potassium persulphate, have come into 
use to correct certain defects of flour made from native wheats. The 
addition of phosphorus trichloride and pentachloride and various phos- 
phorus and sulphur compounds has also been proposed. 

Alum in Flour. — Alum was formerly used in Europe, both by miller and 
baker, to improve the appearance of inferior or slightly damaged flour, but 
now is rarely if ever employed, and the presence of notable quantities of 
aluminum compounds in flour or bread is usually due to alum baking 
powder. 

Bleaching of Flour.— In 1908 about 80% of the flour produced in the 
United States was bleached by nitrogen peroxide, but as a result of the 
enforcement of the federal law the practice has been largely discon- 
tinued. The gas is generated by electrical, chemical, or electro-chemical 
means, and is diluted with air before treatment of the flour. In the 
Alsop process, which is most commonly employed, it is formed by a 
flaming discharge of electricity, which causes the nitrogen and oxygen 
of the air to combine. 

Nitrogen peroxide destroys almost immediately the yellow color which 
is associated with the fat of the flour, thus increasing the whiteness of 
the product. It also forms with the moisture of the flour nitrous and 
nitric acids, the former (free or combined), being easy of detection. A 
considerable part of the nitrous nitrogen remains in yeast bread after 
baking and nearly all of it in soda biscuit. Bleaching also diminishes the 
iodine number of the fat, affects the quality of the gluten, and injures 
the flavor of the bread. 

Recently bleaching with chlorine has come into use. 

Aging versus Bleaching.— Storage under proper conditions slowly 
whitens flour, improves its baking properties, increases its organic acidity, 
diminishes its water-content and brings about other changes not well 
understood. Nitrogen peroxide immediately whitens flour but does not 
improve its baking properties, increase its organic acidity nor appreciably 
affect its water-content. It does, however, introduce nitrous and nitric 
acids. Often 2 parts of nitrous nitrogen per million are recoverable and 
sometimes 6 or 7 parts, but this gradually disappears so that after some 
months hardly a trace remains. 



326 



FOOD INSPECTION AND ANALYSIS. 



The extent to which typical flours are whitened by aging and by 
bleaching so as to contain 2 parts of nitrous nitrogen per million is apparent 
from the gasoline color values in the following table by Winton : 





Minnesota, 
Hara Spring. 


Nebraska, 
Hard Winter. 


Michigan, 
Soft Winter. 


Missouri, 
Soft Winter. 




78% 
Patent. 


22% 
Clear. 


80% 
Patent. 


20% 
Clear. 


80% 
Patent. 


20% 
Clear. 


40% 
Patent. 


60% 
Clear. 


Gasoline color value of 
Unbleached: 

New 


2.00 
1.78 
1.20 
0.72 

0.60 
0.44 
0.30 
0.30 


2.60 
1.82 
1-34 
0.88 

0.66 
0.54 
0.50 
0.50 


2.63 
2.12 
1.36 
0.70 

0.80 
0.46 

0.34 
0.24 


2.50 
2.17 
1.68 
0.82 

0.80 
0.48 
0.40 
0.36 


1-43 
1.22 
0.80 
0.56 

0.40 
0.26 
0.20 

o.iS 


1. 61 

1-49 
1.20 
0.72 

0.38 
0.36 

0.40 


1-47 
1.22 
0.68 
0.48 

0.32 
0.22 
0.18 
0.14 


1.60 


Aged 10 weeks. . . . 

Aged 20 " 

Aged 30 " 

Bleached: 

New 


1-33 
0.88 
0.52 

0.40 


Aged 10 w:eeks. . . . 

Aged 20 " 

Aged 30 " 


0.26 
0.24 
0.16 



INSPECTION AND ANALYSIS OF FLOUR. 

In some of the larger cities, authorized inspectors are appointed 
by boards of trade to pass upon the quality of flour. To such inspectors 
dealers submit samples, which are gauged as to color, soundness, weight, 
Qtc, comparing them usually with a series of graded samples, and stamp- 
ing or branding 'them officially with the date as well as the grade. Market 
quotations also are based on the standard terms adopted. The names 
of the various grades differ with the locality. In St. Louis, the following 
names are adopted in order of the quality, viz., Patent, Extra Fancy, 
Fancy, Choice, and Family. 

The grade or quality of flour is determined largely by its color, fine- 
ness, odor, absorption, and dough-making properties. Baking tests are 
also relied on to a considerable extent by millers and buyers. 

Of the chemical methods those for ash, protein, gluten, acidity, fat, 
and fiber are of chief importance. 

Fineness. — The granulation is determined by rubbing the flour between 
the thumb and fingers. A gritty flour is one that feels rough and granular, 
due to aggregates of cells with contents intact. Smooth flour, on the 
other hand, feels soft and slippery. It is so finely ground that the cells 
are isolated and often ruptured, thus liberating the contents. 

Pekar Color-test. — Place 10-15 grams of the flour on a rectangluar 
glass plate, about 12 cm. long and 8 cm. wide, and pack on one side in a 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 327 

straight line by means of a tlour trier. Treat the same amount of the 
standard flour used for comparison in the same manner, so that the 
straight edges of the two flours are adjacent. Carefully move one of 
the portions so as to be in contact with the other, and " slick " both 
with one stroke of the trier, in such a manner that the thickness of the 
layer diminishes from about 0.5 cm. on the middle of the plate to a thin 
film at the edge, and the line of demarcation between the two flours is 
distinct. Cut off the edges of the layer with the trier, so as to form a 
rectangle, and compare the color of the two flours. The difference in 
color becomes more apparent after carefully immersing the plate with 
the flour in water, and still more apparent after drying. 

Gasoline Color Value. — Winton Method.— F\a.ce 20 grams of the 
flour in a wide-mouthed glass-stoppered bottle of about 120 cc. capacity 
and add 100 cc. of colorless gasoline. Stopper tightly and shake vigor- 
ously for five minutes. After standing sixteen hours, shake again for a 
few seconds until the flour has been loosened from the bottom of the 
bottle and thoroughly mixed with the gasoline, then filter immediately 
through a dry ii-cm. paper, previously fitted to the funnel with water 
and thoroughly dried, into a flask, keeping the funnel covered with a 
watch-glass to prevent evaporation. In order to secure a clear filtrate, 
a certain quantity of the flour should be allowed to pass over on to the 
paper and the first portion of the filtrate passed through a second time. 

Determine the color value of the clear gasoline solution in a Schreiner 
colorimeter, using for comparison a 0.005% water solution of potassium 
chromate. This solution corresponds to a gasoline number of i.o and 
may be prepared by making 10 cc. of a 0.5% solution up to one liter. 
The colorimeter tube containing the gasoline solution should first be 
adjusted so as to read 50 mm., then the tube containing the standard 
chromate solution raised or lowered until the shades in both tubes match. 
The reading of the chromate solution, divided by the reading of the 
gasoline solution, gives the gasoline color value. 

Absorption and Dough Test. — Stir 30 grams of the flour in a heavy 
coffee cup with 15 cc. of water by means of a spatula until a smooth 
ball of dough has been formed. If after standing two minutes, the 
amount of water proves insufficient to thoroughly dough up the flour, 
repeat the operation, using 15.5 cc. of water, and, if necessary, continue 
to repeat until the quantity is found that will yield a stiff, but thoroughly 
elastic dough. From the results of this test, calculate the absorption of 
1000 grams of flour in terms of cc. of water. 



328 FOOD INSPECTION AND ANALYSIS. 

The physical characters of the dough, such as color and elasticity, 
furnish valuable indications of the quality or grade of the flour. 

Expansion of Dough. — Rub to a smooth paste 3.5 grams of granu- 
lated sugar, 1.2 grams of salt, and 3 grams of compressed yeast, and 
thoroughly mix with 60 cc. of water at 35° C. Warm 100 grams of the 
flour in a shallow pan to 35° C, add to it the yeast mixture, mix with 
a spatula, and knead with the fingers until a smooth ball of dough has 
been formed. Drop the dough into a graduated, 500-cc. cylinder, pat 
down so as to force out the air, and note the volume of the mass. Place 
in a raising closet kept at 35° C. Read the volume at the end of 
the first hour and every half hour thereafter until the maximum is 
reached. 

Baking Tests. — These should be carried out in such a manner as to 
produce the best results with the kind of flour used and the purpose for 
which it is intended — whether for yeast bread, soda-biscuit, pastry, or 
crackers. Only tests for bread flours are here taken up, although methods 
for flours designed for other purposes may be easily devised to suit the 
conditions. 

In judging the loaf the chief points are volume, shape, flavor, odor, 
texture, and color. 

Two types of bread baking tests are in general use, (i) the long fer- 
mentation, or more accurately the short sponge, straight dough method, 
and (2) the straight dough method, best known in the form described 
by John Koelner of Milwaukee who also supplies a special kneader and 
other apparatus. 

Apparatus. — i. The Proofing or Raising Closet is a kind of incubator 
with double doors, provided with one or more electric lamps or other 
heating device to keep the temperature at about 32° C. 

2. Kneader.— HsLud kneading is recommended for the long fermenta- 
tion process. The combined mixer and kneader supplied by Koelner 
is used with his process. 

3. Baking Tins for the long fermentation method are 16.8x8.8 cm. 
at the top, 14.9 X6.g cm. at the bottom, and 13.9 cm. deep (inside measure- 
ments) with aprons on both sides to prevent the falling over of the loaf. 
Those for the Koelner method are 27x6.3 cm. at the top, 25.4X5 cm. 
at the bottom, and 8.8 cm. deep (inside measurements) and do not have 
aprons. 

4. Oven. — The best form is an electric oven provided with three heats 
(low, medium, and full) ; a gas or kerosene oil oven may also be used. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 329 

A thermometer passes through a hole in the top so that the bulb is on a 
level witl; the baking tins and the portion of the graduation showing the 
desired temperature is outside of the oven. 

5. Volume Measure. — For determining the size of the loaf a tight 
box is provided of such a size as to hold the largest loaf obtained by the 
method with which it is used, but no larger. The box is first filled with 
flaxseed without jarring, the excess struck off by means of a straight edge, 
and the seed weighed. The capacity of the box (in cc. or cu. in.) is then 
divided by the weight of the seed (in grams or pounds) thus obtaining a 
constant showing the value of the unit in weight in terms of volume. In 
actual test the loaf is introduced into the box, flaxseed added until full, 
the excess struck off, and the weight of the seed determined. This weight 
multiplied by the constant obtained above gives the volume of the seed 
which, subtracted from the total volume of the box, gives the volume of 
the loaf. 

Long Fermentation Method. — The process in general is as follows* 
Weigh out 340 grams of flour and 6 grams of shortening into a mixing 
bowl and place in the proofing closet together with a thorough mixture of 
yeast, sugar, salt, and water sufficient to make a moderately stiff dough 
as calculated from the absorption. After 30 minutes prepare a dough 
from the flour, shortening, and yeast mixture and place in the proofing 
closet, where it is kept for 50 minutes. Pull, knead, return to the proofing 
closet, and allow to raise for about 40 minutes. Knead and pull a second 
time, place in tins, keep for 30-50 minutes in the proofing closet, and 
finally bake at 200-205° C. 

While the proportions for the yeast mixture must be varied to suit 
the conditions the following will serve as a guide: fresh compressed yeast 
9 grams, salt 3.5 grams, sugar 12 grams, water as calculated from the 
absorption for 340 grams of flour. 

Snyder, who has had a wide experience in scientific and commercial 
flour testing, observes: 

" In baking tests the method of procedure must be appreciably varied 
to correspond with the individual characteristics of the flour that is being 
tested. Uniform and inflexible methods of making baking tests that are 
alike applicable to all kinds of flours cannot be given, as a method that 
would give the best baking results with one type or kind of flour often 
gives very poor results when applied, unmodified, to another kind or 
type of flour. Each flour tested is entitled to the quantity and kinds of 
ingredients and method of manipulation as may be necessary to produce 



330 FOOD INSPECTION AND ANALYSIS. 

the best loaf of bread from a physical point of view, that the flour is 
capable of making. 

" Some flours require more and some less of the sponge to make the 
right kind of a dough, Then, too, it may be necessary to slightly vary 
the amounts of yeast, salt, sugar, etc., in order to get the best baking results 
from flours made from different kinds of wheat. 

" A standard flour of known baking character is usually put through 
the process at the same time the flour in question is being tested. Sometimes 
baking tests are defective because the yeast is old or of poor quality. The 
technical skill of the individual who makes a baking test is a matter of 
very great importance in assigning a proper value to the results." 

Straight Dough or Koelner Method. — This process is useful in dis- 
tinguishing certain grades of flour, such as patents and clears by the volume 
of the loaf, and in testing for flavor, but is limited in its value because the 
manipulation is not varied to suit the conditions. 

Warm 220 grams of the flour, in a shallow pan in a raising closet kept 
at 35° C, transfer to a Koelner dough kneader, warmed to 35° C. by 
means of water placed in the special compartment, add 12 grams of sugar, 
5 grams of salt, and 10 grams of compressed yeast, rubbed smooth in a 
cup with 100 cc. of water at 35° C. Rinse the cup with sufficient water 
to make the total quantity required, (usually about 87 cc.) as calculated 
from the absorption test. Adjust the blades of the kneader for mixing, 
and turn 90 revolutions per minute for 10 minutes. Adjust the blades 
for kneading, add 120 grams of flour at 35° C, and turn 60 revolutions 
per minute for 10 minutes. Remove the dough immediately to a warmed 
plate, cut into two equal parts, mould the two separately, and place end 
to end in a warmed, greased, and tared baking tin. Weigh the tin with 
dough, place a tin gauge across the top, and set the whole in the raising 
closet. After the dough has risen to the gauge bake at 200 to 205° C. 
until 30 grams of water have been removed, which usually requires from 
30 to 35 minutes. Break the loaf in two, and note .the odor when hot 
and again when cold, also the flavor when cold. 

Determination of Water, Fat, Fiber, and Protein. — Employ the methods 
described on pages 285 to 287. The crude fiber should be collected and 
weighed on a Gooch crucible. 

Determination of Ash. — Char 3-5 grams of the flour in a flat-bottomed 
platinum dish heated on a piece of thin asbestos board over a Bunsen burner. 
Complete the burning at dull redness, preferably in a muffle furnace. 
If the ash is black or dark gray add a few drops of nitric acid, evaporate 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 331 

to dryness on a water-bath and again heat at dull redness, repeating 
the treatment if necessary. 

Determination of Moist and Dry Gluten.* — Place 25 grams of the 
flour in a coffee cup, add 15 cc. of water at a temperature not to exceed. 
15°, and work the mass into a ball with a spatula, taking care that none 
of it adheres to the dish. Allow the dough to stand one hour, then knead 
in a stream of cold water over a piece of bolting cloth held in place by 
two embroidery hoops, until the starch and soluble matters are removed. 
Place the gluten thus obtained in cold water, and albw to rem^ain for 
one hour, after which press as dry as possible between the hands, roll 
into a ball, place in a tared flat-bottomed dish, and weigh as moist gluten. 
Spread the gluten out in the dish, dry for 24 hours, in a boiling water- 
oven, and weigh again, thus obtaining the dry gluten. 

Because of the inaccuracies of determining gluten by washing many 
cereal chemists employ only determinations of nitrogen calculating the 
protein therefrom by the factor 5.70. 

Determination of Alcohol - soluble Protein (Crude Gliadin). — 
Chamberlain Method. — Digest 2.5 grams of the sample with 125 cc. of 
70% (by vol.) alcohol for 24 hours, shaking every half hour during the 
first 8 hours. Filter through a dry paper, determine nitrogen in 100 cc. 
of the filtrate, and multiply the result by 5.7. 

Determination of Gliadin.— ■SwyJg/' Method. '\ — Place 15.97 grams of 
the flour and 100 cc. of alcohol (sp. gr. 0.90) in a 300-cc. flask, shake at 
intervals for 3 hours, and let stand over night. Filter through a dry filter * 
and polarize in a 220-mm. tube. Precipitate the proteins in 50 cc. of the 
filtrate with 5 cc. of Millon's reagent, filter, and polarize in a 22o.-mm. 
tube, increasing the reading by 50%. Deduct the sum from the first 
polarization and multiply the difference by 0.2. The product is the per 
cent of nitrogen as gliadin, which, multiplied by 5.7, gives the per cent 
of gliadin. 

Olson Method.X — Digest 4 grams of the sample with 200 cc. of 50% 
(by vol.) alcohol for 2 hours, shaking at 5-minute intervals, let stand over 
night, filter, and determine nitrogen in 25 cc. of the clear filtrate. Evap- 
orate slowly 50 cc. of the filtrate to within 5 cc, add 50 cc. of water, heat 
nearly to boiling, and evaporate to about 10 cc. Add another portion 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 81, 1904, p. 118. 
t Jour. Amer. Chem. Soc, 27, 1905, p. 106S. 
} Jour. Ind. Eng. Chem., 5, 1913, p. 917. 



332 FOOD INSPECTION AND ANALYSIS. 

of 50 cc. of water and evaporate to 35 cc. or less., let cool to room tem- 
perature, filter, returning to the filter until clear, determine nitrogen in 
th2 filtrate, and subtract from the total alcohol-soluble nitrogen. The 
difference is gliadin nitrogen. 

Gliadin Ratio. — Snyder considers the percentage of gliadin in the total 
protein (gliadin ratio) more significant than the gliadin-glutenin ratio of 
Fleurant.* 

Determination of Salt-soluble Protein. — Chamberlain Method.-\ — Di- 
gest 10 grams of the flour with 250 cc. of 5% potassium sulphate solu- 
tion, as described under Alcohol-soluble Protein, Determine nitrogen 
in 50 cc. of the filtrate, and multiply the result by 5.7. 

Determination of Albumin, Globulin, and Amides. — Olson Method.X — 
Digest 10 grams of the sample with 500 cc. of 1% sodium chloride solution 
for 2 hours, shaking at 5-minute intervals, let stand over night in a cool 
place, and filter clear. Boil down 200 cc. of the filtrate to 20 cc. or less, 
and evaporate slowly to dryness on a hot plate. Digest the solid mass with 
loo-cc. portions of 55% (by vol.) alcohol, filter, and wash with 55% 
alcohol. Determine nitrogen in the precipitate and correct for blank, 
thus obtaining the albumin (leucosin) nitrogen. 

Evaporate the alcoholic filtrate to within 10 cc, add 50 cc. of water, 
boil down to 35 cc, add 15 cc. of water, let cool to room temperature, 
filter, and wash with cold water. Treat the filtrate with phosphotungstic 
acid, filter, wash with water containing phosphotungstic acid, determine 
nitrogen in the precipitate, and correct for blank. This gives the globulin 
(edestin?) nitrogen. 

Determine nitrogen in the filtrate from the phosphotungstic acid pre- 
cipitate and correct for blank. The corrected result is regarded as amide 
nitrogen. 

Olson calculates only the nitrogen in the various forms; the corre- 
sponding proteins may be obtained, using the appropriate factors. See 
page 286. 

Determination of Glutenin.— Subtract the sum of the gliadin, albumin, 
globulin, and amide nitrogen from the total nitrogen and multiply the 
difference by 5.7. 

Determination of Water-soluble Nitrogen. — Rousseaux and Sirot 



* Manuel I'analyse chimique, 1898, p. 308. 

t Loc. cit. 

X Jour. Ind. Eng. Chem., 6, 1914, p. 211. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 333 

Method.'^ — Digest lo grams of the sample in a 200-cc. graduated flask 
for 2-5 minutes in a boiling water-bath with 150 cc. of water, shaking 
frequently. Cool, make up to the mark, filter, and determine nitrogen 
in 50 cc. of the filtrate. 

Determination of Acidity of ¥lom.—Milchell Method.f— Weigh, out 
20 grams of the flour into an Erlenmeyer flask, add 200 cc. of distilled 
water at 40° C, free from carbon dioxide, shake vigorously for 5 minutes, 
and digest at 40° for one hour, shaking every 10 minutes. Filter and 
titrate 100 cc. of the filtrate with N/io sodium hydroxide solution, using 
phenolphthalein as indicator. Calculate the acidity as per cent of lactic 
acid, (i cc. N/io NaOH = 0.009 gram). 

If the distilled water used contains an appreciable amount of carbon 
dioxide, it should previously be boiled in a Jena flask until neutral, but 
not long enough to dissolve alkali from the glass. Two hundred cc. 
of the boiled water should remain colorless on addition of phenolphthalein, 
but should take on a distinct pink color when mixed with a single drop 
of tenth-normal alkali. 

Determination of Cold-water ExtrsLCt—Wa^tklyn Method.— Mix 100 
grams with distilled water in a graduated liter flask, shake frequently 
during 6 or 8 hours and allow to stand over night. Decant on a filter, 
rejecting the first portions that run through, and evaporate 50 cc. of the 
clear filtrate to dryness in a tared metal dish on a water-bath. The weight 
of the dried residue multiplied by 20 gives the cold-water extract which, 
according to Wanklyn, should not exceed 5%. 

Determination of Iodine Number of the Fat.— Dry over sulphuric 
acid for three days sufficient flour to yield 0.2 to 0.25 gram of fat and 
extract for 16 hours in a Johnson extractor with 25 cc. of absolute ether, 
into a tared 35-cc. flask. Drive off the ether and dry at 100° C. for 15- 
minute periods to constant weight, passing a current of dry hydrogen 
through the flask. Proceed according to the Hanus method, adding 
the chloroform and iodine solution directly to the flask, and breaking 
the flask within a wide-mouthed glass-stoppered bottle for the final 
dilution and titration. 

Detection of Improvers.— Phosphorus and sulphur compounds may be 
determined in the ash after burning with sufficient sodium carbonate 
to form sodium phosphate and sulphate, thus preventing loss by volatiliza- 

* Compt. rend., 156, 1Q13, p. 723. 

t U. S. Dept. Agric, Bur. of Chem., Bui. 122, igog, p. 54. 



334 FOOD INSPECTION AND ANALYSIS. 

tion. The well-known method of burning with magnesium nitrate is useful 
in fixing phosphorus compounds. Ready-formed sulphates may be deter- 
mined in the solution obtained without burning by boiling with 2% 
hydrochloric acid. The dextrose formed by the hydrolysis of the starch 
does not interfere. See 'page 362. Microchemical methods should 
also prove useful. The mechanical separation of certain inorganic salts 
by the chloroform method, page 336, is recommended. Because of the 
great variety of improvers which may be added, definite instructions are 
not possible. 

Detection of Alum. — Logwood Test. — Mix 10 grams of the sample 
with 10 cc. of water and stir in i cc. of logwood tincture (5 grams log- 
wood digested in 100 cc. alcohol) and i cc. of a saturated solution of am- 
monium carbonate. If the sample is pure, the color will be a faint brown 
or pink, but if alum is present, a distinct lavender-blue color is produced, 
which should remain after heating for 2 hours in the water-oven. 

Lenz Hematoxylin Test.* — Mix in a test tube 2 grams of the flour 
with 3 cc. of water and i cc. of 1% hematoxylin in 50% alcohol, then shake 
vigorously with 10 cc. of saturated salt solution. With pure flour the 
deposit which settles is flesh color, while with flour containing alum it 
is bluish or slate color. 

Borghesi Test.\ — Shake 10 grams of the flour 5-10 minutes with 100 
cc. of water, filter, and precipitate the proteins in the filtrate with con- 
centrated tannin solution. Filter again and add 2 drops of cochineal 
tincture or 1% alcoholic alizarin solution. If alum is present the solu- 
tion takes on a crimson color with cochineal or orange-red with alizarin. 
The test is accurate to 0.2% of alum. 

Detection of Peroxide Bleaching in Flour. — Place on the " slicked " 
surface of the flour a drop or two of a mixture of equal parts of solutions 
(a) and (6), described below. If the flour is unbleached and has not 
been stored under conditions permitting absorption of nitrous acid, the 
liquid, which does not immediately soak into the flour, will remain colorless 
or nearly so, while if it is bleached it soon takes on a marked pink or 
crimson color, varying in degree with the extent of bleaching. A pos- 
itive test should be supplemented by determinations of nitrous nitrogen 
and gasoline color value, making suitable allowance if the flour has been 
aged. 



* Apoth. Ztg., 26, 191 1, p. 687. 

t Giom. farm, chim., 59, 1910, p. 49. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 335 

Determination of Nitrous Nitrogen. — Griess-Ilosvay Method.'^ — This 
method, commonly employed for the determination of nitrites in water, 
is well adapted for the estimation of the extent to which fiour has been 
bleached by nitrogen peroxide or nitrosyl chloride. 

1. Reagents. — (a) Snlphanilic Acid Solution. — Dissolve 0.5 gram of 
sulphanilic acid in 150 cc. of 20% acetic acid. 

ih) Alpha-naphtylamine Hydrochloride Solution. — Dissolve 0.2 gram 
of the salt in 150 cc. of 20% acetic acid with the aid of heat. 

(c) Standard Sodium Nitrite Solution. — Dissolve 0.1097 gram of dry 
C.P. silver nitrite in about 20 cc. of hot water, add 0.05 gram of C.P. 
sodium chloride, shake until the silver chloride flocks and make up to 
1000 cc. Draw off 10 cc. of the clear solution and dilute to i liter. One 
cc. of this solution contains 0.000 1 mg. of nitrogen as nitrite. 

Suitable silver nitrite is on the market; it may also be prepared as 
follows: mix a warm concentrated solution of 8 parts of sodium nitrite 
with a warm concentrated solution of 16 parts of silver nitrate. When 
cool collect the precipitate on a Buchner funnel and wash with cold 
water. Dry quickly on a water-bath with as little exposure to light as 
possible. Long continued drying at 100° C. causes it slowly to decompose. 

2. Determination. — Weigh out 20 grams of the flour into an Erlen- 
meyer flask, add 200 cc. of water free from nitrites, previously heated 
to 40° C, close the flask with a rubber stopper, shake vigorously for 5 
minutes, digest i hour at 40°, shaking every 10 minutes, and filter on a 
dry folded filter free from nitrites. As the first portion of the filtrate is 
usually turbid, it should be returned to the filter and the operation re- 
peated until a clear liquid is secured. Dilute 50 cc. of the filtrate and 
also 50 cc. of the standard nitrite solution each with 50 cc. of water, add 
2 cc. each of solutions (a) and (h) ; shake and allow to stand one hour to 
bring out the color. Compare the two solutions in a colorimeter. Divide 
the height of the column of the standard solution by that of the solu- 
tion of the sample, thus obtaining the parts of nitrogen as nitrous acid 
(free or combined) per million of flour. 

Detection of Chlorine Bleaching in Flour. — Determine the gasoline 
color value (page 327), the iodine number of the fat (page 2)32)) ^ ^'^'^ the 
chlorine in the fat expressed in terms of mgs. per kilo. If the bleaching 
is slight, the iodine number will not be reduced sufficiently to detect the 
bleaching; when, however, the bleaching is considerable the iodine number 

* Bull. chim. [2], 2, p. 317. 



336 , FOOD INSPECTION AND ANALYSIS. 

may be reduced ten points or even more. Whenever possible comparisons 
should be made with unbleached flour of the source and grade of the 
suspected sample. 

Determination of Chlorine in the Fat.— Dry at ioo° C. for a few 
hours a portion of the flour sufficient to yield about 0.2 gram of fat and 
extract the nearly dry residue with absolute ether until most of the fat is 
removed. Evaporate the ether extract in a platinum dish with sodium 
carbonate free from chlorine and ignite at dull redness. Take up in 
cold water, add a slight excess of nitric acid, filter, wash, and determine 
chlorine by Volhard's method, using diluted standard solutions in order 
to insure greater accuracy. Precaution must be taken to use chlorine- 
free reagents and filter paper, washing the latter if necessary, and avoid 
possible contamination from the air and other sources. 

Bamihl Test for Gluten {Modified by Winton^). — This test serves 
to detect wheat flour mixed with rye and other flours. 

Place a very small quantity of the flour (about 1.5 milligrams) on a 
microscope slide, add a drop of water containing 0.2 gram of water- 
soluble eosin in 1000 cc, and mix by means of a cover glass, holding the 
latter at first in such a manner that it is raised slightly above the slide, 
and taking care that none of the flour escapes from beneath it. Finally 
allow the cover glass to rest on the slide, and rub it back and forth until 
the gluten has collected into rolls. The operation should be carried 
out on a white paper so that the formation of gluten rolls can be 
noted. 

Wheat flour or other flours containing it yields by this treatment a 
copious amount of gluten, which absorbs the eosin with a\ddity, taking 
on a carmine color. Rye and corn flour yield only a trace of gluten, and 
buckwheat flour no appreciable amount. The preparations are best 
examined with the naked eye, thus gaining an idea of the amount of 
gluten present. Under the microscope traces of gluten, such as are 
formed in rye flour, are so magnified as to be misleading. 

In case the flour is coarse, or contains a considerable amount of bran 
elements, as is true of buckwheat flour and low grade wheat flour, the 
test should be made after bolting, as the bran particles and coarse lumps 
interfere with the formation of gluten rolls. 

Chloroform Test. — This serves in separating mineral impurities and 
improvers; also aids in distinguishing wheat and rye flour. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 217. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 337 

Beneke * shakes vigorously i part of the flour with 3-4 parts of chioro- 
form, then adds 1-2 parts more of chloroform, shakes again, and examines 
the deposit after 24 hours. Dirt and added mineral matter first settle, 
then organic matter, chiefly aleurone cells, gradually deposits. The aleur- 
one cells of rye are blue or olive green, those of wheat yellow-brown. 
Chemical tests should be made of any mineral deposit other than dirt and 
microscopic examination of the organic deposit. 

The sedimentation apparatus devised by Spaeth will be found con- 
venient. The settlings collect in the half-bored stop-cock, which when 
closed permits the pouring off of the supernatant liquid. 

Microscopic Examination.— General instructions are given on page 
314. In distinguishing lye flour from wheat flour whether occurring, 
singly or in mixture, the difference in the cross cells (pages 315-317) 
should be especially noted; these, however, are present in considerable 
amount only in the cheaper grades of wheat flour. The Bamihl and 
chloroform tests furnish supplementary information. 



CORN (MAIZE) MEAL. 

Process of Manufacture.— Although the production of Indian corn 
is greatest in the " corn belt " of the Middle West, the consumption of 
corn meal and grits as human food is greatest in the Southern States of 
the Union where in certain sections it forms the chief article of diet. The 
Southern mills follow the old-time stone process and the meal consists 
of the kernel ground entire with or more often without the removal of a 
portion of the bran. In the Northern miHs, however, the roller system 
is employed, the germ and other offal being commonly removed by special 
machinery preliminary to grinding. The milling and bolting processes 
are usually so conducted as to secure in addition to meal a large yield of 
grits or hominy used both in brewing and as a table cereal, also a certain 
amount of corn flour which is utilized in pancake mixtures and as a filler 
for sausage. Drying is usually essential to prevent spoilage. 

Stone-ground whole-kernel meal is preferred by many in the South 
because of its characteristic oily flavor, but degerminated and bolted meal, 
such as is obtained by the roller process, has better keeping qualities 
owing to the smaller amount of oil. 



Land. Vers. Stat., 36, 1889, p. 337. 



338 



FOOD INSPECTION AND ANALYSIS. 



Composition of Com Meal.— The composition of whole kernel meal 
is the same as of the corn from which it is ground except for loss of a por- 
tion of the moisture if the corn was excessively moist. The range in 
composition of degerminated bolted meal from white and yellow corn 
as reported by Winton, Burnet, and Bornman * is given below: 



Acidity. 



White corn meal : 

Max 

Min 

Yellow corn meal 

Max 

Min 



Water. 


Protein. 


Fiber. 


Nitrogen- 
free 
Extract. 


Fat. 


Ash. 


18.28 


8.84 


0.96 


78.40 


2.31 


0.81 


11.97 


5. 81 


0.58 


72.41 


0.70 


35 


17.8s 


8.63 


0.76 


76.64 


I. 81 


0.65 


13.01 


6.63 


0.46 


71.98 


0.33 


0.24 



23.0 

10.6 

19.7 

14.0 



Spoilage of Meal. — Although the theory that the disease pellagra 
is caused by spoiled meal has been quite generally abandoned, it behooves 
the miller to grind sound corn and dry the meal and the dealer to market 
the product before it has become sour, moldy, or rancid. 

Various Italian and Austrian authors lay stress on the determination 
of acidity and certain qualitative tests in detecting spoilage. Corn or 
meal with an acidity of more than 30 as determined by the following 
method is regarded by Schindler as unfit for consumption. 

Determination of Acidity. — Schindler Method.^ — Weigh 10 grams of 
the meal (which should pass a sieve of 20 meshes to the inch) into a 50-cc. 
glass- stoppered graduated flask, fill to the mark with 85% by volume 
neutral alcohol (prepared by distilling 95% alcohol with quicklime) and 
allow to stand 24 hours with occasional shaking. Decant the clear liquid 
onto a folded filter and pipette 25 cc. of the filtrate into a beaker. Add 
100-150 cc. of well-boiled distilled water, a few drops of phenolphthalein 
solution and titrate with twentieth normal sodium or potassium hydroxide 
solution. Express the results in terms of cc. of normal alkali per kilo of 
meal. 



BREAD AND CAKE. 

Bread is a term broadly applied to all baked cereal products. Un- 
leavened bread, pilot or ship biscuit, and corn pone or hoe cake, which 

* U. S. Dept. of Agric, Bui. 215, 1915. 

t Anleitung zur Beurteilung des Maises und seiner Mahlprodukte mit Rucksicht auf 
ihre Eignung als Nahrungsmittel. Insbruck, 1909, p. 37. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 339 

are the simplest forms of bread, are made entirely of cereal flour or meal, 
water and salt, the aeration being effected by the formation of steam 
and the expansion of inclosed air during heating in the oven. Air and 
steam also serve as the leavening agents for various dry biscuits or 
crackers, pie crust, puff paste and beaten biscuit, but in these more or 
less fat is used as shortening. 

In a narrower sense bread is understood to mean the raised product 
rendered light and porous by a gas generated before or during baking. 
This gas is commonly carbon dioxide generated either by the fermentive 
action of yeast on the sugar of the dough, alcohol also being formed in 
the reaction, by the action of bacteria as in salt-rising bread, or by the 
action of acid ingredients on sodium bicarbonate. Leavening may also 
be brought about by ammonium carbonate from which ammonia gas 
and carbon dioxide are liberated during baking. 

In making ordinary bread the flour is kneaded up with water or milk, 
salt, shortening, and yeast. Malt extract is also used by some bakers 
because of its diastatic action and flavor, and yeast foods to save yeast 
and conserve the carbohydrates. The dough is allowed to rise in a warm 
place, the gas formed during the fermentation converting the mass into a 
light sponge. 

During the subsequent process of baking, which should take place • at 
a temperature between 230° and 260° C, further expansion ensues, much 
of the water is driven off, and the porous mass sets to form the loaf, the 
outside of which is converted into a brown crust, due to the caramelizing 
of the dextrin and sugar into which the starch of the outer layers is con- 
verted. Among other changes that take place in the interior or " crumb " 
during baking are (i) the partial breaking up of the starch grains, which 
however, largely retain their identity, though in some degree distorted in 
shape; (2) somewhat obscure changes in the character of the proteins; 
and (3) partial oxidation of the oil or fat. 

The well-made loaf should possess an agreeable odor, and a sweef, 
nutty flavor, entirely free from mustiness. It should not be tough or 
soggy on the one hand (due to under-raising), nor extremely dry and 
spongy on the other (indicative of over-raising). Over- raising, moreover 
produces sourness, due to advanced lactic fermentation. 

Composition of Bread. — The following table gives the average com- 
position of bread from Bui. 13, part 9, of the Bureau of Chemistry: 



340 



FOOD INSPECTION AND ANALYSIS. 



Kind of Bread. 



No. of 


Moisture 


Protein, 


Ether 


Crude 


Salt. 


Ash. 


Carbohy- 
drates, 


pies. 




NX6.2S. 


Extract. 


Fiber. 






Excluding 
Fiber. 


lO 


38.71 


8.87 


1.06 


0.62 


0.57 


1. 19 


53 72 


2 


33-02 


7 


94 


I 95 


0.24 


0.56 




05 


56.75 


9 


34.80 


8 


93 


2.03 


I 13 


0,69 




59 


53 40 


7 


33-42 


8 


63 


0.66 


0.62 


1 .00 




84 


56. 21 


9 


34-41 


7 


60 


1.48 


0.30 


0.49 




00 


56.18 


48 


7 13 


10 


34 


8.67 


0.47 


0.99 




57 


73 17 


II 


27.98 


8 


20 


341 


0.60 


0.69 




31 


59.82 



Calculated 
Calories of 
Combus- 
tion. 



Vienna 

Home-made . 

Graham 

Rye 

Miscellaneous 

Biscuits 

Rolls 



4435 
4467 

4473 
4338 
4429 

4755 
4538 



The table which follows is a summary of analyses of bread from 
cheaper bakeries made in the author's laboratory: 



Kind of Bread. 



No. of 
Analyses. 



Weight of 
Loaf in 
Grams. 



Water, 
Per Cent. 



Per Cent 

Ash in 

Terms of 

Solids. 



Acidity.' 



White 

Ma.ximum 

Minimum 

Mean 

Graham 

Ma.ximum 

Minimum 

Mean 

Whole wheat 

Diabetic 

Muffins 

Rye 

"Black" 

German with seeds 

Brown 

"Knackerbrod" . . 



44 



653 
126 

430 

500 

367 
420 

507 
445 
194 
1291 
550 
417 
500 
no 



45.20 

33-00 
40.72 

45.20 
40.10 
41.50 
45.10 
47.00 
48.20 

47-15 
47.00 
42.30 
48.10 
8.00 



1.83 
o 60 

0.85 

1-55 
0.96 
1.26 
1.20 
2.20 

1-15 
2.13 
2.20 

0-95 
3-50 
1-94 



6.2 

1-3 
2.6 



4-2 
2.1 

3-5 



1-7 
10. o 



* Cubic centimeters of tenth-normal soda required to neutralize 10 grams of the fresh bread. 

The physical characteristics of bread, its color, taste, odor, porosity^ 
etc., together with determination of moisture, ash, and acidity will usually 
enable the analyst to pass judgment on its quality. 

Water in Bread.— The amount of water is of considerable importance, 
and, in the best bread, varies from $^ to 40 per cent. A larger content 
of water than 40% should be considered objectionable in a white bread, 
both on the ground of acting as a make weight, and because a large excess 
of moisture tends to cause the growth of mold. 

Acidity of Bread. — The degree of sourness of a sample of bread, if 
made from sound flour, indicates the extent to which the fermentation of 
the dough has been carried. To neutralize the acidity of 10 grams of 
the normally sweet loaf of wheat bread, an average of 2 cc. of the standard 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 341 

alkali solution is required, corresponding to 0.72 gram of lactic acid per 
loaf of an average weight of 400 grams. The loaf of rye bread exhibiting 
th^e maximum sourness or acidity in the above table required 10 cc. of 
standard alkali per 10 grams of bread, corresponding to 11. 6t grams 
lactic acid in the loaf of 1291 grams. Rye bread, particularly the coarse 
variety known as " Pumpernickel,'" is often so prepared as to be sour 
to the taste. 

Congdon obtained an average acidity equivalent 2.19 cc. N/io alkali 
per TO grams in the crust of bakers' bread and 1.78 cc. in the crumb. 
In home-made bread he found 1.6-2. i cc. for the crust and 1.25-1.45 
cc. for the crumb. He believes the acidity to be due partly to lactic acid 
(about 0.03%) produced during fermentation which reacts to form lacto 
acid phosphate and phosphoric acid, and partly to hydrochloric acid 
(about 0.10%) formed by the action of phosphoric acid on sodium chloride. 
White, also Barnard and Bishop (page 342) have found that the acidity 
does not increase on keeping the bread. 

Fat in Bread. — It is well known that the amounts of fat or ether 
extract as obtained by the ordinary method and expressed in most bread 
analyses are too low, being considerably less than the combined fat of 
the materials entering into its composition. This is probably due to 
the partial oxidation of the fat and its incrustation with insoluble 
matter. 

Yeast Foods.— Kohman, Hoffman, Godfrey, Ashe, and Blake,* in 
extensive investigations carried out at the Mellon Institute under fellow- 
ships of the Ward Baking Co. found that in different regions, owing to 
variations in the composition of the water, marked differences in the action 
of yeast, and consequently in the character of the bread were obtained. 
When, however, they added to the quantity of f]our (100 lbs.) required 
for making 160 lbs. of bread, 2 ounces of calcium sulphate, i ounce of 
ammonium chloride, and 0.02 ounce of potassium bromate, a saving of 
50-65% of the yeast and 2% of fermentable carbohydrates (calculated 
in terms of the flour) was effected, the quality of the dough was conserved, 
the control of the process was facilitated, and better and more uniform 
bread was secured. The calcium and ammonium salts act as yeast foods 
while the bromate exerts an oxidizing influence, aging and maturing 
the dough and preventing so-called " rottenness " which reduces the 



* Jour. Ind. Eng. Chem., 8, 1916, p. 781. 



342 FOOD INSPECTION AND ANALYSIS. 

gas-retaining qualities. The composition of the bread was not appre- 
ciably different from bread made without the salts, except that the lime 
was slightly higher. • 

Alum was formerly added to flour by the baker as well as the miller 
to cover defects or spoilage, influencing the quality of the gluten. Its 
use in the United States, at least in recent years, has not been reported. 
In examining flour or oven products for alum due regard must be given 
its possible presence in the form of baking powder. 

Copper Sulphate, said to have been used many years ago on the con- 
tinent, does not appear to have ever found a place in English or American 
bakeries. 

The Wrapping of Bread is in accord with modern ideas of cleanliness 
and sanitation. Win ton has seen the baker's delivery man drop an un- 
wrapped loaf in the filth of a city alley and restore it to its place in 
his wagon. Had the loaf been'"wrapped, possible consequences would 
have been mitigated. The bread is commonly allowed to cool before 
wrapping. 

An exhaustive investigation of the effects of wrapping on the character 
and composition of the bread has been conducted by Barnard and Bishop.* 
They concluded (i) that wrapping either in semi-porous waxed or para- 
fined paper retards the escape of moisture and tends to preserve the colloidal 
condition and physico-chemical equilibrium and thus prevent staling, 
also, contrary to common belief, the loss of moisture of the crumb is 
accompanied by a closely parallel loss of the crust, (2) lactic acidity does 
not develop either in wrapped or unwrapped bread, thus confirming the 
results of White,! and (3) wrapping does not injure the quality of the 
loaf after the third day and up to that time improves its condition, fkvor, 
and odor. 

Cake and Similar Preparations. — These differ from bread chiefly by 
the addition of considerable sugar, butter, spices, and other flavoring 
materials. In gingerbread, molasses is used as an important ingredient 
besides ginger. The adulterants of molasses, such as glucose, salts of 
tin, etc., would thus sometimes occur in gingerbread. In fact stannous 
chloride has been found in ginger cakes. $ 

The following analyses of a few typical varieties of cakes are selected 
from Bulletin 13 of the Bureau of Chemistry: 

* Jour. Ind. Eng. Chem., 6, 1914, p. 736. 

t N. Dak. Agric. Exp. Sta., Spec. Bui. 26, 1910, p. 214. 

J See U. S. Dept. of Agric, Bur. of Chem., Bui. 13, p. 1369. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



343 



I 

[Kind of Cake. 


Nioisture 


Protein, 
NX6.2S. 


Ether 
Extract. 


Crude 
Fiber. 


Ash. 


Salt. 


Sugar. 


Other 
Carbohy- 
drates. 


Cal- 
culated 
Calories. 


Doughnuts. . 
Ginger snaps. . 
Fruit cake. . . 
Gingerbread. . 
Cup cakes. . . . 
Macaroons . . , 
Jumbles 


21 6l 

4. 86 

-M-47 
21.49 
14.81 
8.06 
13-34 


6.73 
6.06 
4-56 
6.2s 
5.24 
6.67 
7.62 


19-33 
15-44 
12.35 
8.42 
15-56 
12.97 

14-79 


0.60 
0.79 

0.90 
0.27 
1. 41 
1 .04 


0.40 
1.82 

1-55 
1 . 21 
0.82 
0.97 


0.03 
0.47 

0.28 

0-34 
0.07 

0-39 


1.28 
28.66 

9-48 
32.48 
58.77 
16.60 


50.64 
24.90 

52.46 
30.89 
10.89 
46.31 


5529 
4971 

4757 
5073 
4835 
5133 



METHODS OF ANALYSIS. 

Preparation of the Sample.— Weigh a whole loaf, divide into quarters 
by cutting through the center at right angles to the sides and ends, weigh 
one of the quarters, break up into pieces, dry at a moderate heat, 
grind without loss, and weigh, and calculate the loss of moisture. A 
more representative sample is secured by using quarters of several loaves. 
If desired, crust and crumb may be prepared separately. 

Determination of Moisture.— Proceed as with flour, taking into account 
the moisture driven off in preparing the sample. 

Determination of Fat.— Owing to the presence of gelatinized starch, 
which incloses the fat globules, direct extraction yields results much too 
low. Doubtless some, if not all the results for fat given in the tables, 
page 340 and above, were obtained by faulty methods. 

The Polenske-Grujic Method "^ gives the full amount of fat: Heat 
on a boiling water-bath for 90 minutes 5 grams of the sample in a 200-cc. 
flask with 50 cc. of water and 2 cc. of 25% hydrochloric acid (sp. gr. 
I.I 25), cool, add I cc. of 0.04% methyl orange solution, neutralize with 
concentrated sodium hydroxide solution, and acidify with a drop of dilute 
hydrochloric acid. Filter, wash with hot water, dry filter and contents 
on a watch-glass at 105° C, and extract with ether in the usual manner. 

Determination of Fiber, Starch, Sugars, Protein, and Ash.— See 
general methods (pages 285 and 286), also pages 292 and 293. 



YEAST. 

The yeast plant is a fungus of the genus Saccharomyces, widely dis- 
tributed through the vegetable kingdom and in the air. It is capable 
of rapid growth by the multiplication of its cells when present in a 

* Eighth Int. Cong. App. Chem., 26, 1912, p. i. 



344 FOOD INSPECTION AND ANALYSIS. 

favorable medium, such as malt wort, and with propitious conditions 
of temperature, moisture, etc. Under such conditions, it forms a yel- 
lowish, viscous, frothy substance, the chief value of which, in the liquor 
industry, is the production of alcohol, while for bread-making, as a result 
of the same kind of fermentation, the end desired is the leavening of the 
doughy mass by the carbon dioxide liberated. 

A vigorous, pure yeast which will " raise " quickly is a great preventive 
against sour bread, for not only is it comparatively free from the germs and 
products of lactic acid fermentation, but by doing its work quickly it 
enables the baker to check the fermentation or raising process before the 
lactic acid or sour decomposition is far advanced. 

Yeast most commonly used in bread-making is of the so-called " com- 
pressed " variety. The use of compressed yeast is almost universal for 
domestic purposes, and is more or less common in bakeries. A small 
amount of brewers' yeast in liquid form from beer wort is used, especially 
in the immediate neighborhood of breweries, and dry yeasts are used to 
some extent in localities so remote that fresh compressed yeast cannot 
readily be obtained. 

Compressed Yeast is a product of distilleries where the wort from 
malt and raw grain is fermented for the manufacture of whiskey, gin, 
and other distilled liquors, as well as distilled vinegar. Little, if any, 
of the commercial compressed yeast is made from beer wort yeast. 

In the manufacture of compressed yeast, the yeast floating on the 
top of the wort is separated by skimming, while that settling to the bot- 
tom is removed by running the wort into shallow settling trays. Top 
yeast is considered more desirable than bottom yeast for bread-making. 
The separated yeast is washed in cold water, and impurities are removed, 
either by sieving through silk or wire sieves, or by fractional precipitation 
while washing. The yeast, with or without the addition of starch, is 
finally pressed in bags in hydraulic presses, after which it is cut into cakes 
packed in tin-foil, and kept in cold storage till distributed for use. 

Such yeast should be used when fresh, as it readily decomposes and 
soon becomes stale. When fresh, it should have a creamy, white color, 
uniform throughout, and should possess a fine, even texture; it should 
be moist without being slimy. It should quickly melt in the mouth 
without an acid taste. Its odor is characteristic, and should be some- 
what suggestive of the apple. It should never be " cheesy," such an 
odor indicating incipient decomposition, as does a dark or streaked color. 

Dry Yeast is prepared by mixing fresh yeast with starch or meal, 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 345 

molding into a stiCf dough, and drying, either in the sun or at a moderate 
temperature under reduced pressure. Such yeast, when dry, is cut into 
cakes and put in packages. It will keep almost indefinitely. During 
the drying process, many of the yeast cells are rendered torpid and tem- 
porarily inert, and for this reason the dried yeast does not act so promptly 
in leavening as does compressed or brewers' yeast, but when once it begins 
to act it is c{uite as efificacious. 

Composition of Yeast. — The following is the result of the analysis 
of under-fermentation yeast, after drying, by Nagele and Loew: 

Cellulose and Mucilage 37 

Albuminoids (Mycroprotein, etc.) 36 

Albuminoids (Soluble in Alcohol) 9 

Peptones (Precipitable by Subacetate of Lead). 2 

Fat.--. 5 

Extractive Matters (Leucin, Glycerin, etc.). ... 4 

Ash 7 



100 



Lintner gives the following average analyses of the ash of three samples 
of yeast, analyzed by him : 

Silica 1-34 

Iron (Fe203) o . 50 

Lime (CaO) 5.47 

Sulphuric anhydride (SO3) 0.56 

Magnesia (MgO) 6.12 

Phosphoric Anhydride (P2O5) 50 - 60 

Potash (K2O) and a little Soda 33-49 

98-08 

Matthews and Scott give the following as the ash composition of yeast: 

Potassium Phosphate 78.5 

Magnesium Phosphate 13.3 

Calcium Phosphate 6.8 

Silica, Alumina, etc 1.4 

TOO.O 



346 FOOD INSPECTION AND ANALYSIS. 

Starch in Compressed Yeast. — Potato, corn, or tapioca starch has 
long been added to yeast before pressing, on the ground that the starch acts 
as a drier, producing a much cleaner product, and one that can be more 
readily and intimately mingled with the materials of the bread, besides 
enhancing the keeping qualities of the yeast, especially in warm weather. 
The quantities used vary from about 5% up to over 50%. Undoubtedly 
the larger amounts are added as a make weight. Some manufacturers 
use no starch whatever. 

The question has frequently been raised whether, with improved 
methods of manufacture, whereby yeast can be produced comparatively 
free from slime, and thus capable of pressure without the admixture of 
starch, the use of the latter should not be considered as an adulterant. 

Briant claims that the admixture of starch up to 5% increases rather 
than decreases the actual content of yeast, in that the starch abstracts 
moisture from the yeast cells themselves, the proportion of water being 
much smaller, and that of the yeast larger in the starch-mixed substance. 
T. J. Bryan,* on the other hand, finds that the addition of starch to yeast 
reduces the carbon dioxide value, and that the percentage reduction is 
greater than the percentage of starch present. His experiments further 
indicate that the keeping qualities of starch yeast are not greater, but 
actually less than that of pure yeast. 

U. S. Rulings. t — I. The term " compressed yeast," without quali- 
fication, means distillers' yeast without admixture of starch. 

2. If starch and distillers' yeast be mixed and compressed such prod- 
uct is misbranded if labeled or sold simply under the name " compressed 
yeast." Such a mixture or compound should be labeled " compressed 
yeast and starch." 

3. It is unlawful to sell decomposed yeast under any label. 

ANALYSIS OF YEAST, 

Microscopical jExamination. — Mix a bit of the yeast in water on the 
glass slip till a milky fluid is formed, and stir in a drop of a very weak 
anilin dye solution, such as methyl violet, eosin, or fuchsin (i gram crys. 
fuchsin, 160 cc. water, i cc. alcohol). Put on the cover-glass and examine 
under the microscope. Living, active cells resist the stain, if the latter 
is dilute enough, and appear colorless or nearly so, while the decayed and 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 116, 1907, p. 25. 
t Food Insp. Decision, iii, 1910. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



347 



lifeless cells are stained and can easily be distinguished by their color. 
Yeast cells are circular or oval in shape and vary from 0.007 to 0.009 
mm. in diameter. They are sometimes isolated and sometimes grouped 
in colonies; each cell has an outer, mucilaginous coating or envelope. 
The interior, granular mass or substance of the cell is the protoplasm, 
and within the protoplasm are frequently seen one or more circular empty 
spaces known as vacuoles. 




Fig. 68. — Sprouting Yeast-cells (Saccharomyces cerevisice). {a, after Liirssen; b, after 

Hansen). 

Yeast cells multiply by the process of budding. The decadence of 
yeast cells is marked by the increased size of vacuole and by the thicken- 
ing of the cell wall. 

Determination of Leavening Power. — The value 
of yeast in bread-making depends on the amount 
of carbon dioxide which it is capable of generating 
under given circumstances, hence the available 
carbon dioxide is the chief factor in gauging a yeast- 
There are various methods of determination: (i) 
either by measuring the volume of gas set free by 
the action of a weighed quantity of yeast in a 
sugar solution of known strength, kept for a fixed 
time at a fixed, temperature (say 30°), or (2) by 
conducting the gas from such a fermenting solution 
through a weighed absorption bulb, containing 
potassium hydroxide and noting the increase in 
weight, or (3) by the more convenient method of 
Meissl as follows: 

A mixture is made of 400 grams pure, concen- 
trated sugar, 25 grams ammonium phosphate, and 25 
grams potassium phosphate. A small wide-mouthed 
flask of about 100 cc. capacity (Fig. 69) is fitted with 
a doubly perforated rubber stopper, having two tubes, one of which is 
bent and passes nearly to the bottom of the flask, being fitted at the outer 




Fig. 69. — Apparatus for 
Determining Leaven 
ing Power of Yeast. 



348 FOOD INSPECTION AND ANALYSIS. 

end with a rubber tube and glass plug, while the other is connected with 
a small calcium chloride tube. Measure 50 cc. of distilled water into 
this flask, and dissolve 4.5 grams of the above sugar phosphate mixture. 
Finally add i gram of the yeast to be tested, stir it well till there are no 
lumps, and cork the flask. Carefully weigh on a delicate balance the 
flask with Its contents, and immerse in a water-bath at 30° C, keeping 
it at that temperature for 6 hours. At the end of this time, remove the 
flask from the bath, and immediately immerse in cold water to cool the 
contents. Remove the rubber tube with the glass plug, and by suction 
draw out the remaining carbon dioxide. Replace the plug, and having 
carefully wiped off the flask, again weigh. The loss in weight is due to 
carbon dioxide set free by the fermentation of the yeast. 

CHEMICAL LEAVENING MATERIALS. 

Under this heading are included the various chemicals, added sep- 
arately, or mixed in the form of baking powder, for the aeration of oven 
products. 

Sodium Bicarbonate. — Sodium hydrogen carbonate, acid sodium 
carbonate, baking soda, or saleratus (NaHCOs), is produced in large 
quantities by the Solvay process, ammonia and carbon dioxide gases 
being alternately passed into concentrated sodium chloride solution under 
pressure. The bicarbonate, being almost insoluble in cold concentrated 
ammonium chloride solution, separates out. As placed on the market 
for baking powder it is a white powder with a disagreeable alkaline taste. 

According to the United States Pharmacopoeia, matter insoluble in 
water, heavy metals, and appreciable amounts of normal carbonate should 
be absent. No ammonia fumes should be evolved on heating in a test 
tube and after drying over sulphuric acid the powder should consist of at 
least 99% pure sodium bicarbonate. 

A small amount of harmless impurity, such as sodium chloride, may 
be present. Because of its cheapness there is no incentive to adulteration. 

Cream of Tartar, or potassium bitartrate (KH5C4O6), is obtained 
by the recrystallization of crude argols. The lees, or argols, consist 
chiefly of crude potassium bitartrate, which is present in the juice of the 
grape, but being insoluble in alcohol is deposited during fermentation. 
If the wine has been plastered calcium tartrate will be found in the lees 
and also, if not eliminated, in the cream of tartar. 

Calcium acid phosphate, gypsum, starch, and alum have been used 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 349 

as adulterants, while small amounts of lead from the tanks in which the 
cream of tartar is crystallized constitute a common impurity. 

Potassium bitartrate is insoluble in alcohol, sparingly soluble in cold, 
and readily soluble in hot water. It is usually guaranteed 99% pure. 

Baking Powder. — Formerly the housewife was accustomed to measure 
out in proper proportion an acid substance, such as sour milk, molasses, 
or cream of tartar, and sodium bicarbonate (" saleratus ") to produce 
quick aeration of bread. The modern baking powder is a natural out- 
growth of this practice and has largely displaced it, containing, as it does, 
a mixture ready for immediate use of an acid and an alkaline constituent 
in proper proportion for chemical combination to form the gas. A dry, 
inert material, which by absorbing moisture prevents the premature 
chemical action between the reagents, is generally considered an essential 
ingredient. Starch is nearly always preferred for this purpose, though 
sugar of milk has a limited use, and hydrogenated oil, which serves also 
as shortening has recently been proposed. The alkaline principle of 
nearly all baking powders is sodium bicarbonate, in some cases mixed 
with a little ammonium carbonate. 

Classification of Baking Powders. — The division is into three main 
classes, with reference to the acid principle: (i) tartrate powders, (2) 
phosphate powders, and (3) alum powders. Patents have been issued 
for the use in baking powder of lactic acid made from skim milk by the 
action of B. Bulgaricus, thus adding a fourth class to the list. 

(i) Tartrate Powders. — The acid principle is {a) potassium bitartrate 
or {h) tartaric acid, the reactions being as follows ; 

188 84 210 44 18 

{a) KHC4H4O6 +NaHC03 = KNaC4H406 + CO2 +H2O 

Potassium Sodium Potassium Carbon Water 

bitartrate bicarbonate and sodium dioxide 

tartrate 

150 168 230 88 

(6) H2C4H406 + 2NaHC03 = Na2C4H406,2H20+2C02 

Tartaric Sodium Sodium tartrate Carbon 

acid bicarbonate dioxide 

(2) Phosphate Powders contain calcium acid phosphate as the acid 
principle : 

234 168 136 T42 88 36 

CaH4(P04)2 + 2NaHC03 = CaHP04+Na2HP04 + 2C02 + 2H20 

Water 



Calcium 


Sodium 


Calcium 


Disodium 


Carbon 


icid phos- 


bicarbonate 


monohy- 


phosphate 


dioxide 


phate 




drogen phos- 
phate 







350 FOOD INSPECTION AND ANALYSIS. 

(3) "Alum Powders.'' — In these the acidity is due to aluminum sul- 
phate added as such or as potash-, ammonia-, or soda-alum. At present 
calcined or " burnt" soda alum, known commercially as S. A. S. (sodium 
aluminum sulphate) is almost exclusively used, the reaction bemg as 
follows: 

484 504 156 568 264 

Na2Al2(S04)4 + 6NaHC03 = Al2(OH)6+4Na2S04+6C02 

Burnt Sodium Aluminum Sodium! Carbon 

soda alum bicarborrate hydroxide sulphate dioxide 

Baking powders consisting of various mixtures of the above classes 
are also on the market. Alum-phosphate powders are especially popular. 

Composition of Various Baking Powders.— Followmg are analyses 
of typical baking powders of the above classes: * 

1. Cream of Tartar Baking Powder: 

Total carbon dioxide, CO2 13 • 21 

Sodium oxide, Na20 13.58 

Potassium oxide, K2O i4-93 

Calcium oxide, CaO 18 

Tartaric acid, C4H4O5 41-60 

Sulphuric acid, SO3 10 

Starch 7-42 

Water of combination and association by difference. . 8.98 

100.00 
Available carbon dioxide 12.58%. 

2. Phosphate Baking Powder: 

Total carbon dioxide, CO2 13-47 

Sodium oxide, Na20 12 .66 

Potassium oxide, K2O 31 

Calcium oxide, CaO 10. 27 

Phosphoric acid, P2O5 21 .83 

Starch 26.41 

Water of combination and association by difference. . 15 .05 

100.00 
Available carbon dioxide 12.86%. 

* U. S. Dept. of .^gric, Div. of Chem., Bui. 13, part 5, pp. 600, 604, and 606. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 351 



Alum Baking Powder: 

Total carbon dioxide, CO2 9 

Sodium oxide, Na20 9 

Aluminum oxide, AI2O3 3 

Ammonia, NH3 i 

Sulphuric acid, SO3 10 

Starch 43 

Water of combination and association by difference.. 22 



45 

52 

73 
07 

71 
25 
27 



100.00 
Available carbon dioxide 8.10%. 

Mixed Powder: 

Total carbon dioxide, CO2 10.68 

Sodium oxide, Na20 14-04 

Calcium oxide, CaO i . 29 

Aluminum oxide, AI2O3 4. 59 

. Ammonia, NH3 i . 13 

Phosphoric acid, P2O5 3 .38 

Sulphuric acid, SO3 ii-57 

Starch 42.93 

Water of combination and association by difference, . 10 . 39 



100.00 
Available carbon dioxide 10.37%. 

Baking Powder Controversies. — Perhaps no class of substances within 
the domain of food inspection is the subject of so much controversy as 
baking powder. In the absence of special regulations, baking powder can 
be regarded as adulterated if it (i) contains a substance injurious to health, 
(2) if it contains mineral matter, such as clay, ground talc, or calcium 
sulphate, as a diluent, (3) if it is deficient in available carbon dioxide, 
or (4) if it does not conform in composition to the label. 

Metallic Impurities. — Traces of arsenic derived from the raw materials 
used in manufacture often occur in both alum and phosphate powders 
while lead from pipes or vats may be present in tartrate and phosphate 
powders. 

Mineral Diluents. — Win ton, Ogden, and Langley * found over 25% 

* Conn. Agric. Exp. Sta. Rep., 1900, p. 15, 



352 FOOD INSPECTION AND ANALYSIS. 

of ground rock (talc and tremolite) in a sample of baking powder and 
20-30% of plaster, calculated as the anhydrous salt, in several alum- 
powders. Although experiments by Patten* indicate that calcium sul- 
phate liberates a certain amount of carbon dioxide from sodium bicar- 
bonate, its presence in considerable amount is generally regarded as an 
adulterant. 

Deficiency in Available Carbon Dioxide is a mark of adulteration. 
Some powders have been found to yield only half the proper amount. 

Misbranding. — In cases where the general nature of the powder or 
its constituents is declared on the label, whether or not required by state 
laws or rulings, any misstatement constitutes a misbranding. 

Cathartics in the Residue.— The residue left in the bread by all classes 
of baking powder contains one or more cathartics, but opinions differ as 
to whether the amount is sufficient even after long continued use to be 
injurious to health. The nature of these cathartics is shown by the reac- 
tions given above and the approximate amounts may be derived from the 
reactions and the analyses of the baking powder. 

The " Alum Question" involving the completeness of the decomposition 
into aluminum hydroxide and the injurious nature of this substance appears 
to be disposed of for the present by the official report of the Referee 
Board, t which found that aluminum compounds do not (i) injure the 
nutritive value of foods, (2) contribute poisonous or other deleterious 
effect, or (3) reduce the quality or strength of the food. The catharsis 
produced by very large amounts is due to the sodium sulphate formed and 
not the aluminum compound, although occasional colic, when very large 
amounts of aluminum have been injested, is produced. Giess J and 
co-workers § obtained somewhat different results from the Referee Board 
which led them to continue their investigations. 

METHODS OF ANALYSIS OF BAKING CHEMICALS AND BAKING POWDERS. 

Titration of Sodium Bicarbonate. — The degree of purity of sodium 
bicarbonate is best ascertained by titration with standard acid, using 
methyl orange as indicator, each cubic centimeter of tenth-normal acid 
being equivalent to 0.0084 gram of sodium bicarbonate. 



* Jour. Assn. Off. Agric. Chem., 2 II, 1917, p. 214. 

t U. S. Dept. of Agric, Bui. 103, 1914. 

X Biochem. Bui. 5, 1916, p. 151. 

§ Steel, Amer. Jour. Physiol., 28, rgii, p. 94; Kahn, Biochem. Bui. i, 1911, p. 235. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 353 

Titration of Cream of Tartar. — The degree of purity of commercial 
cream of tartar is best determined by weighing out exactly 0.188 gram 
of the sample, dissolving in hot water, and titrating with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. If the article 
is pure, exactly 10 cc. of the standard alkali will be required for the titra- 
tion. All the above-named adulterants, with the exception of alum, 
are either insoluble, or sparingly soluble in hot water, and will indicate 
the impurity of the sample even before titration. If the adulterant be 
alum, the sample would go into solution in the water, but the alum would 
be precipitated by the sodium hydroxide, the precipitate being, however, 
soluble in an excess of the alkali. 

Determination of Total Carbon Dioxide. — Heidenhain Apparatus * 
(Fig. 70).-— This is an evolution of the form devised by Mulder and 
improved by Kolbe, Stobe, and Fresenius.f The apparatus consists of 
the following parts: 

A. A cylinder filled with soda lime to free the air from carbon dioxide. 
A thick layer of cotton prevents soda lime dust from being carried over. 

B. Glass cock to regulate the air current, which finds resistance at C. 

C. A capillary contraction. 

D. Funnel tube of peculiar shape. The funnel is cylindrical, three- 
fourths of an inch v/ide and 4 inches long, and is reduced to half 
its width at the bottom, so as to make a neck for a perforated rubber 
stopper. 

E. A glass tube tightly fitted into the perforated rubber stopper, 
allowing the stopper to be taken out, thus admitting the required amount 
of acid into the flask. 

F. Evolution flask, ordinarily of 150 cc. capacity, but for foaming 
liquids of 300 cc. capacity. 

G. Return condenser, consisting of a glass tube of one-fourth of an 
inch bore, around which a small lead pipe is wound. The tube following 
the condenser contains a few pieces of calcium chloride to retain the 
bulk of the moisture. It is refilled when contents are liquefied. 

H. U-tube filled with coarse calcium chloride. 

K. Tube filled at / with a 3-inch long column of pumice stone impreg- 
nated with copper sulphate completely dehydrated at 150° C. The re- 
mainder of the tube is filled with fine calcium chloride. 



* Jour. Am. Chem. Soc, 18, 1896, p. 1. 

t Quantitative Analysis, German Edition, i, 449; 2, 308. 



354 



FOOD INSPECTION AND ANALYSIS. 



L. Cock to close the apparatus when not in use. 

M. First absorption tube about one-half inch in diameter and 5 inches 
long, filled mainly with soda lime, with a little calcium chloride on the 
side at which the air current enters. 

N. Second absorption tube of same size as M, filled half with soda 
lime and half with calcium chloride, the side containing calcium chloride 
being toward the end of the apparatus where the air current leaves. 

O. Guard tube containing calcium chloride toward N and soda 
lime toward P. 

P. Indicator tube trapped with glycerine. 



'riih77nTii/i'/>y^fii^ 




Fig. 70. — Heidenhain's Apparatus for the'Determination of Carbon Dioxide. Scale, i : 18. 



R. Safety bottle to receive water which may be sucked back from 
the aspirator. 

S. The aspirator, which is a Mariette's bottle of about 4 liters 
capacity. 

Tubes M and N should hold about 20 grams, making the capacity 
of M for carbon dioxide nearly i gram and of N for moisture 0.2 gram. 
They should be refilled when they have gained 0.75 and o.i gram respect- 
ively. Use best rubber connections lubricated with a trace of castor 
oil. Boil connections for the weighed tubes in dilute alkali, wash and dry. 
Wire or tie all joints. Before using pass carbon dioxide through H and 
K for several hours and exhaust. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 355 

Reagents. — i. Calcium Chloride. — This should be dehydrated at 200" 
C, not fused. Grind so as to pass a No. 18 mesh and reject what passes 
a No. 30 mesh. The tubes should be filled from the same lot so that 
the air leaving the apparatus shall have the same moisture content as 
as that which enters. 

2. Soda Lime.^ — To a kilogram of commercial sodium hydroxide 
add 500 to 600 cc. of water and heat in an iron kettle to form a thin 
paste. While still hot add a kilogram of coarsely powdered quicklime 
and stir with an iron rod to mix, break up lumps and facilitate the escape 
of moisture. When cool grind and sift as in the case of calcium chloride, 
place in wide-mouthed bottles, and seal with paraffin. To give the best 
results the product should not be too dry. 

Process. — Weigh tubes M and N after they have reached the room 
temperature, opening the cocks for a moment to insure equalization 
of pressure. Connect tubes with the apparatus and make sure that 
all joints are tight by closing A at the bottom, opening all cocks, starting 
the aspirator, and observing P in which the liquid must soon come to 
a standstill. Then disconnect the aspirator, close B, remove F and 
introduce the material (using about i gram of carbonate or 2 grams of 
baking powder), connect F and start the cooler. Introduce hydrochloric 
acid (sp.gr. i.i) and carbon dioxide-free water through D, lifting E 
slightly. Heat to boiling and lower the flame to keep just at boiling. 
If no more air passes P start the aspirator. When water stops running, 
open B carefully and adjust the outflow of the aspirator by raising or 
lowering the syphon to half the safe speed. 

To find the safe speed charge the apparatus as for an analysis, omitting 
the carbonate, aspirate at the rate of 50 cc. per minute until 2 liters of 
air have passed through the system, and weigh the tubes. If together 
they have lost weight reduce the rate until constant weights are secured. 
Tube M should lose as much as N gains. 

After M has become cool, increase the current to full safe speed and 
aspirate altogether 3 liters, continuing boiling to the end. After the 
tubes have reached the room temperature open for a moment and 
v/eigh. 

Determination of Residual and Available Carbon Dioxide. t — Weigh 
2 grams of baking powder into a flask suitable for the subsequent deter- 
mination of carbon dioxide, add 20 cc. of cold water, and allow to stand 

* Benedict and Tower, Jour. Am. Cham. See, 21, 1899, p. 396. 
t Conn. Agric, Exp. Sta., Rep., 1900, p. 169. 



356 FOOD INSPECTION AND ANALYSIS. 

twenty minutes. Place the flask in a metal drying cell surrounded by 
boiling water and heat, with occasional shaking, for twenty minutes. 

To complete the reaction and drive off the last traces of gas from 
the semi-solid mass, heat quickly to boiling and boil for one minute. 
Aspirate until the air in the flask is thoroughly changed, and determine 
the residual carbon dioxide by absorption, as described, under total 
carbonic acid. 

The process described, based on the methods of McGill * and Catlin,t 
imitates as far as practicable the conditions encountered in baking, but 
in such a manner that concordant results may be readily obtained on 
the same sample and comparable results on different samples. 

To obtain the available carbon dioxide subtract the residual from 
the total carbon dioxide. 

Detection of Tartaric Acid-I — In the absence of starch, mix a little 
of the dry powder in a test-tube with a bit of dry resorcin, add a few 
drops of concentrated sulphuric acid, and heat slowly. A rose-red color 
indicates tartaric acid or a tartrate, the color being discharged on dilu- 
tion with water. 

In case of baking powder, or a cream of tartar substitute containing 
starch, shake repeatedly from 3 to 5 grams of the sample with about 
250 cc. of cold water in a large flask, allowing the insoluble portion to 
subside. Decant the solution through a filter, and evaporate the filtrate 
to dryness, after which test the dried residue or a portion thereof with 
resorcin and sulphuric acid as above described. 

Determination of Total Tartaric Acid. — Modified Heidenhain 
Method.^ — Applicable only in the absence of phosphates and salts of 
aluminum and calcium. 

Into a shallow porcelain dish, 6 inches in diameter, weigh out 2 grams 
of the material and sufficient potassium carbonate to combine with all 
tartaric acid not in the form of potassium bitartrate. Mix thoroughly 
with 15 cc. of cold water, and add 5 cc. of 99% acetic acid. Stir for half 
a minute with a glass rod bent near the end. Add 100 cc. of 95% alcohol, 
stir violently for five minutes, and allow to settle at least thirty minutes. 
Filter on a Gooch crucible with a thin layer of paper pulp, and wash 

* Lab. Inl. Rev. Dept., Canada, Bui. 68, p. 31. 

t Baking Powders: A Treatise on their Character, Methods for Determination of 
the Values, etc., p. 20. 

X Wolff, Rev. chim. anal., 4, 1899, p. 2631. 

§ U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 104J Bui. 107, p. 175. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 357 

with 95% alcohol until 2 cc. of the filtrate do not change the color of 
htmus tincture diluted with water. Place the precipitate in a small cas- 
serole, dissolve in 50 cc. of hot water, and add standard fifth-normal potas- 
sium hydroxide solution, leaving it still strongly acid. Boil for one minute. 
Finish the titration, using phenolphthalein as indicator, and correct the 
reading by adding 0.2 cc. One cc. of fifth-normal potassium hydroxide 
solution is equivalent to 0.026406 gram tartaric anhydride (C^H^OJ, 
0.03001 gram tartaric acid (HjC^H^Oe), and 0.03763 gram potassium 
bitartrate (KKCJip^). 

The standard of the potassium hydroxide solution should be fixed by 
pure dry potassium bitartrate. 

The accuracy of this method is indicated by the agreement of the 
percentages of potassium bitartrate in cream of tartar powders containing 
no free tartaric acid, obtained by calculation from the tartaric acid, with 
those obtained by calculation from the potassium oxide. 

In presence of phosphates or of aluminum and calcium salts, the only 
satisfactory method of arriving at the amount of tartaric acid present is 
by difference, having determined or calculated the other ingredients. 

Kenrick's Polariscopic Methods. — Method i. {Applicable to Cream 
of Tartar). — The method is based on the fact that in the presence of 
excess of ammonia, the rotation of the solution is proportional to the 
concentration of the tartaric acid, and is independent of the other bases 
and acids present. 

(a) The Substance is Completely Soluble in Dilute Ammonia. — A 
weighed quantity of the material containing not more than i gram tartaric 
acid is placed in a 25 cc. measuring flask, moistened with 3 or 4 cc. of 
water, and concentrated ammonia (sp. gr. 0.880) added in quantity suf- 
ficient to neutralize all acids that may be present, and leave about i cc. 
in excess. The actual amount of the excess is not of importance, but a 
greater quantity than i cc. of free ammonia should be avoided. The 
solution is then made up to 25 cc. with water, filtered, if necessary, 
through a dry filter, and measured in a 20 cm. tube in the polarimeter. 

The amount of tartaric acid (CiHgOg) in grams iy) in the material 
taken is given by the formula: 

y =0.005 1 9^, 
where x is the rotation in minutes. 

{b) The Substance is not Completely Soluble in Dilute Ammonia. — In 
this case calcium tartrate is probably present, and may be determined 
as follows: Treat i gram of the substance (or an amount containing 



358 FOOD INSPECTION AND ANALYSIS. 

not more than i gram of tartaric acid) in a small beaker with 15 cc, of 
water, and 10 drops of concentrated hydrochloric acid. Heat gently 
till both the potassium and calcium tartrates have passed into solution, 
and then, while still hot, add 2 cc. of concentrated ammonia (or enough 
to produce an ammoniacal smelling liquid), and about o.i gram of sodium 
phosphate dissolved in a little water. Transfer to a 25-cc. measuring 
flask, cool, make up to the mark with water, filter through a dry filter, 
and polarize the filtrate in a 20-cm. tube. The tartaric acid is calculated 
from the formula given under (a). 

The precipitation of the calcium by means of sodium phosphate is 
not absolutely necessary, but when this is not done, in cases where the 
proportion of calcium in the sample is high, there is a great tendency 
for the calcium tartrate to crystallize out from the ammoniacal solution 
before the reading is made. 

The tartaric acid present as bitartrate of potash may be determined 
by proceeding as in (a), the calcium tartrate being practically insoluble 
in cold ammonia solution. 

The tartaric acid present as calcium tartrate is given, with sufficient 
accuracy for most purposes, by the difference between the results of (a) 
and (b). If more accurate results are required, the residue insoluble in 
ammonia in (a) may be dissolved in a little hydrochloric acid and treated 
as above with sodium phosphate and ammonia. 

Method 2. {Applicable to Baking Powder and Cream of Tartar mixed 
with Substitutes). — Direct readings of rotation in ammoniacal solution 
are inadmissible in analyses of the substances of this class, on account 
of the influence of iron and aluminum on the rotation of tartaric acid, 
and on account of the small but unknown rotation of the trace of inverted 
starch. 

Accurate determinations, however, may be made in the presence of 
excess of ammonium molybdate in neutral solution. The latter substance 
has the property of greatly increasing the rotation of tartaric acid, so 
that by its use the small rotation of the inverted starch is made insignifi- 
cant. It is to be noted, however, that this increased rotation is very 
sensitive to the presence of alkali and acid, and is, moreover, modified 
by phosphates. It is therefore necessary, in the first place, to remove 
the phosphoric acid, and, secondly, to bring the solution to a definite 
state of neutrality. Both these results are attained by the following 
procedure, the details of which must be carefully adhered to: 

(a) Reagents. — The following solutions must be prepared, but need 
not be made up very accurately: 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



359 



Molybdate solution: 44 grams ammonium heptamolybdate in 250 cc. 

Citric acid solution: 50 grams citric acid in 500 cc. 

Magnesium sulphate solution: 60 grams MgS04 . 7H2O in 500 cc. 

Ammonia solution: 80 cc. concentrated ammonia (sp. gr. 0.880) in 
500 cc. 

Hydrochloric acid: 60 cc. concentrated hydrochloric acid in 500 cc. 

Methyl orange solution: 

{b) Process. — An amount of material containing not more than 0.2 
gram tatraric acid, not more than 0.3 gram alum, and not more than 
0.3 gram calcium superphosphate, is accurately weighed, and placed in 
a dry flask. To this, 5 cc. of citric acid and 10 cc. of molybdate solution 
are added, and allowed to react with the substance for 10 or 15 minutes 
(with an occasional shake). Next, 5 cc. of magnesium sulphate solution 
are added, and 15 cc. of ammonia solution stirred in. After a few 
minutes (not more than one hour), the solution is filtered through a dry 
filter, a slight turbidity of the filtrate being disregarded. To 20 cc. of 
the filtrate are then added a few drops of methyl orange and hydrochloric 
acid, from a burette, till the pink color appears (2 or 3 drops too much 
or too little are of no consequence). Finally, 10 cc. more of the molybdate 
solution are added to the pink solution, which now becomes colorless or 
pale yellow, and water is added to make up the volume to 50 cc. This 
solution, after filtering if necessary, is polarized in a 20-cm. tube. 

The amount of tartaric acid in grams (y) in the weight of substance 
originally taken is given by the following formula, in which jc is the rotation 
in minutes: 

y = 0.00 io36.v + 0.00 i6oiv'-V- 
But if the rotation is not less than 40', the simpler formula, 

y = 0.0075 +0.001 168.V, 
may be employed. 

The following table gives the tartaric acid in grams for every 10 minutes 
rotation : 



Rotation in Minutes. 


Grams 

Tartaric 

Acid. 


Rotation in Minutes. 


Grams 

Tartaric 

Acid. 


10 


0.016 

0.029 

0.0415 

0.0535 

0.0657 

0.0776 

0.0895 

O.1013 




0.1130 
0.1246 

0.1365 
0.1479 

0.1595 
O.1710 
0.1825 


20 

30 

40 

50 

60 

70 

80 


100 


1 10 


1 120 


130 

140 

150 





360 FOOD INSPECTION AND ANALYSIS. 

Determination of Starch. — McGiWs Method* {Modified). — Digest 
I gram of the sample with 150 cc. of a cold 3% solution of hydrochloric 
acid during twenty-four hours, with occasional shaking. Filter through 
a tared Gooch crucible, wash first with water until neutral, then once 
with alcohol, and finally with ether. Dry at 110° C. for four hours, cool, 
and weigh. Burn off the starch, and again weigh. The difference in 
the two weights indicates the weight of the starch. The purity of the 
starch is insured by examination with the microscope. 

Acid Conversion Method. -f — If the sample contains lime, mix 5 grams 
in a 500-cc. flask with 200 cc. of 3% hydrochloric acid, and let the mixture 
stand an hour with frequent shaking. Filter through a wetted 11 -cm. 
filter, wash with water, and transfer the starch by a wash-bottle from the 
filter-paper back into the original flask, using 200 cc. of water. 

If the sample be free from lime, weigh 5 grams directly into the 500-cc. 
flask with 200 cc. of water. In either case add 20 cc. of hydrochloric 
acid (specific gravity 1.125) and heat the flask in boiling water for 2^ 
hours, the flask being provided with a reflux condenser. Determine the 
dextrose, and from this the starch in the regular manner. 

Detection of Aluminum Salts. { — (a) In Baking Powder. — Appli- 
cable in presence of phosphates. Burn to an ash about 2 grams of the 
sample in a platinum dish. Extract with boiling water and filter. Add 
to the filtrate sufficient ammonium chloride solution to produce a distinct 
odor of ammonia. A flocculent precipitate indicates aluminum. 

In igniting, as above directed, sodium aluminate results from the 
more or less complete fusion. The reaction which occurs may be repre- 
sented as follows: 

Na^Al^O^-f 2NH,Cl-f 4H2O = Al2(OH)e-f- 2NH,OH-f 2NaCl. 

Sodium Ammonium Aluminum Ammonia Salt 

aluminate chloride hydroxide 

If any phosphate of lime be present, it will be insoluble in the solution 
of the ash. If phosphate of sodium or potassium be present, it will go 
into solution, but will only precipitate out when an aluminum salt is also 
present on the addition of the ammonium chloride reagent. 

(b) In Cream 0} Tartar. — Mix about i gram of the sample with an 
equal quantity of sodium carbonate, bum to an ash, and proceed as in 
the case of baking powder (a). 

* Canada Inland Rev. Bui. 68, p. 7,^. 

•f U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 105; Bui. 107 rev., p. 176. 

X Leach, 31st An. Rep. Mass. State Board of Health, 1899, p. 638. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 361 

Determination of Alumina. — The above qualitative method with am- 
monium chloride may be made quantitative in presence of phosphates 
as follows: After carrying out the qualitative method as above directed, 
filter off the final precipitate, dissolve it in nitric acid, and test it for phos- 
phate with ammonium molybdate. If phosphates are found absent, 
proceei as before with a weighed amount of the sample and wash, ignite, 
and weigh the residue as AI2O3. 

If phosphate is found present in the ammonium chloride precipitate, 
proceed as before, igniting and weighing the total residue. Then deter- 
mine the P2O5 in the latter and subtract from the total. The difference 
will be the AI2O3. 

Determination of Lime. — 5 grams of the sample are treated in a 
500-cc. graduated flask with 50 cc. of water and 25 cc. of concentrated 
hydrochloric acid. Add water to the mark, shake, and allow the starch 
to settle. Decant through a dry filter, and to 50 cc. of the filtrate 
add ammonia nearly to neutralization, an excess of ammonium 
acetate solution, and 4 cc. of 80% acetic acid, and heat at 50° C. 
Filter if necessary, and precipitate the lime with an excess of 
ammonium oxalate. Filter, wash, and ignite over a blast-lamp. Weigh 
as CaO. 

Determination of Potash and Soda.* — Weigh out 5 grams into a 
platinum dish, and incinerate in a muffle at a low heat. The charred 
mass is well rubbed up in a mortar, then boiled fifteen minutes with 
about 200 cc. of water, to which has been added a little hydrochloric 
acid. The whole is transferred to a 500-cc. flask, and, after cooling, 
made up to the mark and filtered. Of the filtered liquid 100 cc, 
representing i gram of the sample, are measured out, heated to boihng, 
and a shght excess of barium chloride solution added; then without 
filtering barium hydroxide is added in slight excess, the precipitate 
filtered off, and washed. To the filtrate is added a little ammonium 
hydroxide, and ammonium carbonate solution until the barium is pre- 
cipitated. This precipitate is filtered and washed, the filtrate evapo- 
rated to dryness, and carefully ignited below redness until all volatile 
matter is driven off. The residue is dissolved in a few cc. of water, and 
a few drops of ammonium carbonate solution added. The precipitate, 
if any, is removed by filtering and washing, and the filtrate evaporated 
in a small tared platinum dish, ignited below redness, and weighed. 

* Conn. Agric. Exp. Sta. Rep., 1900, p. 178. • 



362 FOOD INSPECTION AND ANALYSIS. 

This gives the weight of the mixed chlorides. The residue is taken up 
with hot water, from 5 to 10 cc. of a loSc- solution of platinic chloride 
added, and the whole evaporated to a sirupy consistency on the wat.r- 
bath; it is then treated with 80% alcohol, the precipitate washed with 
80% alcohol by decantation, transferred to a Gooch crucible, dried l'c 
icx)° C, and weighed. The weight of the precipitate, multiplied by 
0.19308, gives the weight of K2O, and by 0.3056 the equivalent amiount 
of KCl. The weight of KCl found is subtracted from the weight of the 
mixed chloride, the remainder being NaCl, which, multiplied by 0.5300, 
gives the weight of Na^O in the sample. 

Determination of Phosphoric Acid. — Mix 5 grams of the material 
with 10 cc. of magnesium nitrate solution, prepared by dissolving cal- 
cined magnesia in nitric acid, adding magnesia in excess, and filtering, 
dry, ignite, and dissolve in hydrochloric acid. Remove an aliquot part 
of the solution, corresponding to 0.25 gram, 0.50 gram, or i gram, neu- 
tralize with ammonia, clear with a few drops of nitric acid, and proceed 
according to the usual method, precipitating successively with molybdic 
solution and magnesia mixture. 

Determination of Sulphuric Acid. Boil 5 grams of the powder gently 
for ih hours with a mixture of 300 cc. of water and 15 cc. of concentrated 
hydrochloric acid. Dilute to 500 cc, draw off an aliquot portion of ico 
cc, dilute considerably, precipitate with barium chloride, filter through 
a Gooch crucible, ignite, and weigh. Direct solution of the material 
without burning the organic matter was proposed by Crampton.* 

Determination of Ammonia (present in the form of ammonia alum 
or ammon'um carbonate). Mix 5 grams of the sample with 200 cc. of 
water, and add an excess of sodium hydroxide. Distil into standard 
acid, and determine the ammonia by titration. 

Detection and Determination of Arsenic. — Proceed according to the 
Marsh or Sanger-Black-Gutzeit method without preliminary treatment 
(page 64). 

Determination of Lead. — Method of the Victor Chemical Works. — In 
the case of phosphate and alum phosphate powders and of acid phosphate 
weigh I to 2 grams of the material into a small beaker, add 10 to 15 cc. 
of water and 2 to 3 cc. of concentrated sulphuric acid. Bring to a boil 
and if starch is present continue the heating on a water bath until the 
starch is hydrolized, replacing the water lost by evaporation. Cool, 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, part 5, p. 596. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 363 

add 30 to 40 cc. of 95% alcohol, stir and allow to stand over night. If 
a precipitate of sodium aluminum sulphate appears, due to an excess of 
alcohol, add water in small amounts until dissolved. Filter and wash 
with 75 to 80 cc. of alcohol until free from acid. Dry, transfer the bulk 
of the precipitate to a crucible, digest with hot alkaline ammonium 
acetate solution (390 grams of ammonium acetate in 1800 cc. of water 
and 150 cc. of concentrated ammonium hydroxide), filter through the 
paper previously used, and wash with small portions of the hot solution. 
After coohng, make up to 50 cc, add i cc. each of 10% potassium, 
cyanide solution, 1% gelatine solution, and colorless ammonium sul- 
phide solution. Compare with standard lead solution prepared from 
a stock solution of 0.160 gram of lead nitrate (dried over sulphuric acid) 
in 1000 cc. of water (i cc. = 0.0001 gram Pb) and the quantities of alkaline 
acetate, cyanide, gelatine and sulphide already given. 

In the case of tartrate powders and cream of tartar shake 10 grams 
of the material with 50 cc. of water and 40 cc. of 2N ammonia water. 
Make up to 100 cc, mix and filter through a dry filter. Determine lead 
colorimetrically in 50 cc. of the filtrate as above, omitting the preliminary 
precipitation as sulphate. The standard lead solution should be made 
up using about the same amount of lead-free cream of tartar as in the 
solution of the material. 

SEMOLINA AND EDIBLE PASTES. 

Semolina is the coarse meal ground from certain varieties of hard 
or " durum " wheats, grown originally in Italy, Sicily, and Prussia, but 
at present in France and certain parts of the United States and Canada. 
This hard wheat is high in gluten, and especially adapted for the prepara- 
tion of macaroni and the various pastes. A peculiar process is employed 
in preparing the wheat, whereby the husk is removed by wetting, heating, 
grinding, and sifting, the resulting meal or semolina, being in the form 
of small, round, glazed granules. 

Italian Pastes. — Semolina furnishes the basis of the Italian edible 
pastes, being mixed with warm water, kneaded, and molded into various 
forms, either by pressure through holes in an iron plate, or otherwise, 
and finally dried. In parts of Italy juices of carrots, onions, and other 
vegetables are said to be mingled with the paste, but for local consumption 



364 



FOOD INSPECTION AND ANALYSIS. 



only. Saffron is sometimes added to pastes for the purpose, so it is 
claimed, of imparting a spicy flavor, although the quantity used is often 
so small as to be apparent only to the eye, thus indicating that the real 
object of its addition is to impart a color in imitation of an egg paste. 

Macaroni is the larger of the slender-tube or pipe-shaped products; 
vermicelli is the worm-shaped variety, produced when the holes in the 
plate are very small; spaghetti is the term applied to the cord-hke paste 
intermediate in size between the others. A variety of Italian pastes or 
pates is made by rolling the kneaded semolina into thin sheets, and cutting 
out in shapes of animals, letters of the alphabet, etc. 

The composition of some of these products is as follows: 



No. of 
Samples. 



Water. 



Protein. 



Fat. 



Total 
Carbohy- 
drates. 



Crude 
Fiber. 



Ash 



Fuel 
Value 

per 
Pound. 
Cal's. 



Semolina *.. 
Macaroni f - 
Noodles t- - - 
Spaghetti t - 
Vermicelli f. 



3 

15 



10.50 
10.3 
10.7 
10.6 
II. o 



11.96 

13-4 
II. 7 
12. 1 
10.9 



.60 
■9 



0.4 
2.0 



75-79 

74-1 

75-6 

76-3 

72.0 



0.50 

0.4 
0.4 



0.65 

1-3 
i.o 
0.6 
4-1 



1665 
1665 
1660 
1625 



♦Balland. t Atwater and Bryant. 

Noodles are a strap-shaped form of paste made in German households 
as well as in factories. True, or egg-noodles, contain a certain percentage 
of eggs, while water-noodles are practically the same in composition as 
Italian pastes. The difference in composition between water-noodles and 
noodles made with different numbers of eggs or egg yolks per German 
pound of flour, is shown by the analyses of Juckenack and Pasternack * 
given in the following table: f 



u 


Composition of the Dry Matter. 





Composition of the Dry Matter. 


K^ 






















0° 

4) C 

c 


Ash. 


Total 
Phos- 
phoric 

Acid. 


Lecithin 
Phos- 
phoric 
Acid. 


Ether 
Extract 


Protein 
NX6i 


V 

6.. 


Ash. 


Total 
Phos.- 
phoric 
Acid. 


Lecithin 
Phos- 
phoric 
Acid. 


Ether 
Extract 


Protein 
NX6i 


^ 












^2i 














% 


% 


% 


% 


% 




% 


% 


% 


% 


% 





0.460 


0.2300 


0.0225 


0.66 


12.00 





0.460 


0.230c 


0.0225 


0.66 


12.03 


I 


0-565 


0.2716 


0.0513 


1.56 


12.99 


I 


0.488 


0.2720 


0.0518 


1-57 


12.37 


2 


0.664 


0.3110 


0.0786 


2.42 


13.92 


2 


0.516 


0.3127 


0.0801 


2.47 


12.73 


3 
* 


0-758 
* 


0.3482 
* 


0.1044 

* 


3-24 

* 


14.81 
* 


3 
* 


0.542 
* 


0.3520 
* 


0.1075 

* 


3-33 

* 


13.07 
* 


12 


1.426 


0.6123 


0.2875 


7-94 


21.09 


12 


0.745 


0.6533 


O.3171 


8.64 


15-71 



*Zeits. Unters. Nahr. Genussm., 3, 1900, p. 13; 8, 1904, p. 94. 

t The German pound is 500 grams; the avoirdupois pound is 454 grams. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 365 

From these results it appears that the percentages of ash, total phos- 
phoric acid, and protein are appreciably increased by the addition of 
each egg or egg yolk, while the percentages of lecithin-phosphoric acid 
and ether extract are more than doubled by the addition of the first egg, 
and are increased in corresponding proportion by the addition of two or 
more eggs. 

The German Association of Food Chemists require that commercial 
egg-noodles contain at least 0.045% ^^ lecithin-phosphoric acid, and 
2.00% of ether extract, corresponding to the minimum in noodles with 
two eggs per half kilogram of flour. 

Spaeth * considers that if the ether extract of noodles has an iodine 
number over 98, it is safe to assume that they contain no eggs or only 
traces. 

Farcy f determines the nitrogen soluble in hot and cold water. In 
flour or noodles made from flour alone he found about 0.3%, irrespective 
of whether hot or cold extraction was followed, while with pastes containing 
3-5 eggs, the amount soluble in cold water was the same as for water- 
noodles, but that soluble in hot water was 0.45-0.48%. 

In interpreting the results of analysis it should be remembered that 
fat may have been introduced in some form other than in eggs, and that 
the lecithin-phosphoric acid diminishes somewhat on long standing, 
although results obtained by Nochmann % indicate that the loss is slight 
when care is taken to avoid exposure to warm moist air. Allowance 
should also be made for the variation in composition of the eggs and 
flour. 

Of 22 brands of American noodles examined by Winton and Bailey, § 
only 5 appeared to be made with eggs; the lecithin-phosphoric acid in 
these ranged from 0.036 to 0.058, and the ether extract from 1.83 to 2.33 
per cent, while in the other samples the lecithin-phosphoric ranged from 
0.015 to 0.032 and the ether extract from 0.28 to 2.50%. 

Adulteration of Pastes. — Rice, corn, and potato flours have been 
used in the preparation of the cheaper varieties of semolina, but rarely 
in this country. A more common form of adulteration is the substitution 
of water-noodles for egg-noodles, artificial colors being used to carry 
out the deception. Substitutions of this kind are detected by determina- 

* Forschber. Lebensm., 3, 1896, p. 47. 

t Ann. fals., 7, p. 183. 

t Zeits. Unters. Nahr. Genussm., 25, 1913, p. 717. 

§ Conn. Agric. Exp. Sta. Rep., 1904, p. 138; Jour. Amer. Chem. Soc, 37, 1905, p. 137. 



366 FOOD INSPECTION AND ANALYSIS. 

tions of lecithin-phosphoric acid and ether extract, supplemented by tests 
for artificial colors. 

ANALYSIS OF PASTES. 

Determination of Lecithin-phosphoric Acid. — Juckenack's Method* 
— Extract 30 grams of the finely ground material for 10 hours with abso- 
lute alcohol in a Soxhlet extractor at a temperature inside the extractor 
not below 55^-60° C. The extraction flask should be provided with a 
small quantity of pumice stone to prevent bumping during the boiling, and 
the extractor enclosed by asbestos paper, if the desired temperature is not 
readily maintained. After the extraction is completed, add 5 cc. of alco- 
holic solution of potash (prepared by dissolving 40 grams of phosphorus- 
free caustic potash in 1000 cc. alcohol), and distil off all the alcohol. 
Transfer the residue to a platinum dish by means of hot water, evaporate 
to dryness on a water bath, and char over asbestos. Treat the charred 
mass with dilute nitric acid, filter, and wash with water. Return the 
residue with the paper to the platinum dish, and burn to a white ash. 
Treat again with nitric acid, filter and wash, uniting the filtrates. De 
termine phosphoric acid by the usual method. 

Determination of Nitrogen Soluble in Hot and Cold Water. — Farcy 
Method.-^ — Heat 10 grams of the powdered sample and 150 cc. of water 
in a 200-cc. graduated flask in a boiling water-bath for 2 hours with 
occasional shaking, cool, make up to the mark, centrifuge, filter, and 
determine nitrogen in 50 cc. of the clear filtrate. Repeat the operation, 
digesting at room temperature. 

Precipitin Test for Eggs. — Arragon and Bornand | proposed the 
antiserum method of detecting eggs or parts of eggs and Gothe § has de- 
veloped details for conducting the test. While the test is doubtless valuable 
in the hands of a trained serologist, the chemical methods seem more 
practicable for ordinary use. 

Detection of Artificial Colors in Pastes. — The following colors 
have been used in noodles and other pastes: turmeric, saffron, annatto, 
naphthol yellow (Martius yellow), naphthol yellow S, picric acid, aurantia, 
Victoria yellow, tartrazine, metanil yellow, azo yellow, gold yellow, and 
quinoline yellow. Of these naphthol yellow, picric acid, metanil yellow, 

* Zeits. Unters. Nahr. Genussm., 3, 1900, p. 13. 

t Loc. cit. 

X Chem. Ztg., 37, 1913, p. 1345- 

§ Zeits. Unters. Nahr. Genussm., 30, 1915, p. 389. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 367 

and Victoria yellow are injurious to health, and their use is illegal in 
European countries as well as in the . United States. Fortunately, they 
are rarely found in the products now on the market. 

The detection of artificial colors is complicated by the presence of the 
natural coloring matter of the flour and the lutein of eggs. These are 
conveniently extracted by ether, which does not remove the artificial 
colors, although most of them unmixed dissolve freely in this solvent. 

Juckenack's Method.^ — Thoroughly shake two portions of the finely 
ground material, each of about lo grams, in test tubes with 15 cc, of 
ether and 15 cc. of 70% alcohol respectively, and allow to stand 12 hours. 

{a) If the ether remains uncolored or only slightly tinted and the 
material below it remains yellow, while the alcohol is distinctly colored 
and the material is decolorized, a foreign dye is indicated. 

{h) If both ether and alcohol are colored, either (i) lutein (egg color) 
alone, or (2) this with a foreign dye is present. 

1. Treat a portion of the ether solution with dilute nitrous acid, 
according to Weyl. If the ether is not completely decolorized, a foreign 
dye is present. 

2. If the deposit of material below the alcohol is decolorized, while 
that below the ether is colored, tests should be made for foreign dyes as 
follows:. Shake the portion previously treated with ether with three or 
more fresh portions of the same solvent, until no more color is extracted, 
and then shake the residue with 70% alcohol and allow to stand 12 hours. 
After filtering, concentrate the solution slightly, acidify with hydrochloric 
acid, boil with sensitized wool, and identify the color in the usual manner 
(Chapter XVII). 

SchlegePs Method. -f — Extract 100 grams of the finely powdered material 
with ether in a continuous extraction apparatus, and shake the residue 
at frequent intervals for half a day with a mixture of 140 cc. of alcohol, 
5 cc. of ammonia, and 105 cc. water. Filter, evaporate to remove alcohol 
and ammonia, acidify slightly with hydrochloric acid, and again filter. 
Boil the filtrate with sensitized wool, and identify the color on the dyed 
fiber by the usual tests (Chapter XVII). 

Freseniiis Method.X — Extract 20 to 40 grams of the powdered material 
with ether in a continuous extraction apparatus. Dry the residue to 
remove ether, shake for 15 minutes with 120 cc. of 60% acetone, and 



* Zeits. Unters. Nahr. Genussm, 3, 1900, p. i. 

t Untersuchungsanstalt, Niirnberg, Ber., 1906, p. 34 

X Zeits. Unters. Nahr. Genussm., 13, 1907, p. 132. 



368 FOOD INSPECTION AND ANALYSIS. 

allow to stand 12 to 24 hours. Filter, evaporate, until the acetone is 
removed, and divide into two portions, a larger and a smaller. To the 
larger portion add sufficient acetic acid to dissolve flocks, and boil with 
sensitized wool. Remove natural coloring matter from the wool by 
boiling in dilute acetic acid. If after this treatment the wool is dyed 
the presence of a foreign color is indicated, which may be identified by 
the usual tests. 

To the smaller portion of the aqueous solution, obtained after removal 
of the acetone as above described, add an equal volume of alcohol, heat 
to dissolve flocks, divide into four portions, and apply special tests to 
three of these, reserving the fourth for comparison. The natural color 
of the flour is decolorized by hydrochloric acid, intensified by ammonia, 
but not affected by stannous chloride, even on heating. Saffron reacts 
in a similar manner, but is only slightly bleached by the acid, and is not 
affected by the other two reagents. 

Piutti and Bentivoglio Method.^ — This method is especially designed 
to detect the four colors forbidden by Italian law, and to distinguish these 
from naphthol yellow S. 

Add 50 grams of the paste to 500 cc. of boiling water, made alkaline 
with 2 cc. of concentrated ammonia water, add 60 to 70 cc. of alcohol, and 
continue the boiling 40 minutes. After filtering, acidify the Ij^^uid with 
2 to 3 cc. of dilute hydrochloric acid and boil with 5 to 6 strands of sensi- 
tized wool, each strand weighing about 0.5 gram. Wash the wool, 
dissolve the color in dilute ammonia, and repeat the dyeing. After 
dissolving a second time '11 ammonia, evaporate the solution of the dye 
to dryness, avoiding as far as possible the formation of a skin, and take 
up the residue in water. If a skin has formed, filter and test the insoluble 
matter for metanil yellow with dilute hydrochloric acid, and for picric 
acid with ammonium sulphide. 

To I cc. of the filtrate add stannous chloride solution and a little 
sodium hydroxide, or preferably sodium ethylate. If no red color forms, 
nitro-colors are absent; if, also, in another portion dilute hydrochloric 
acid produces no violet color, thus showing the absence of metanil yellow, 
no further test is necessary. In the presence of these colors, acidify the 
remainder of the solution with acetic acid, shake violently with carbon 
tetrachloride, and identify the color according to the following scheme: 

A. Color dissolves in carbon tetrachloride to colorless solution. 
Extract with very dilute ammonia, concentrate and divide into two parts. 

* Gaz. chim. ital. 36, II, 1906, p. 385. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 369 

1. Acidify with hydrochloric acid, and add i to 2 drops of stannous 
chloride and ammonia in excess. A rose colored solution and precipi- 
tate form Naphthol yellow. 

2. Acidify slightly with hydrochloric acid, add a little zinc dust and 
stir. Solution becomes rose-violet Victoria yellow. 

B. Color is insoluble in carbon tetrachloride. Evaporate to dryness 
on water-bath, take up in water and divide into three parts. 

1. Hydrochloric acid produces a violet coloration Metanil yellow. 

2. Ammonium sulphide produces a red brown coloration. 

Picric acid. 

3. Stir on a water-bath with zinc dust and ammonia, filter, treat with 
zinc dust and hydrochloric acid and again filter, (a) Potassium hydroxide 
produces a yellow coloration, and {h) ferric chloride an orange coloration. 

Naphthol yellow S. 

Schmitz-Dumont Test for Tropeolins.* — Moisten a small portion of 
the material with a few drops of dilute hydrochloric acid. The formation 
of a reddish or bluish color shows the presence of an azo color or some 
other coal-tar color. 

Martini Test for Saffron.-\ — Tx-eat 50 grams of the finely powdered 
material in the cold for 24 hours with 100 cc. of 70% alcohol, shaking 
occasionally, or reflux for 15 minutes. Filter the extract, concentrate to 
a paste on the water-bath, and extract the residue with ether, thus re- 
moving interfering colors. Heat the residue on the water-bath until 
all ether is removed, then add 98% alcohol and continue the heating 
thus gradually dissolving the saffron color. Filter the alcoholic solution, 
evaporate on the water-bath, and test the residue which in the presence 
of saffron takes on a blue color changing to violet, green, and brown with 
concentrated sulphuric acid and a transient green color with concentrated 
nitric acids. 

Test for Turmeric. — Extract the color from the ground material by 
alcohol and identify by the boric acid test (Chapter XVII). 

CEREAL BREAKFAST FOODS. 

The large number and variety of these preparations now on the market 
testify to the fact that breakfast cereals form a most important, as well 
as considerable, portion of our food supply. These foods are generally 
prepared from wheat, oats, corn, and rice, and are, as a rule, remarkably 

* Zeits. off. Chem., 8, 1902, p. 424. 
t Bol. chim. farm., 52, p. 37. 



370 FOOD INSPECTION AND ANALYSIS. 

pure and free from adulteration, though the food value of different varieties 
is often grossly misstated by their manufacturers. Formerly the break- 
fast food consisted entirely of the coarsely ground, generally decorticated, 
raw cereal grain, and required a long period of cooking to prepare it for 
use. At present many of the oat products, and to some extent also those 
of com, rice, and w^heat, are subjected to a more or less preliminary cook- 
ing and drying, whereby they are capable of being prepared for use in 
a much shorter time, and their keeping qualities are enhanced. The 
so-called rolled oats are prepared by softening the grains through steam- 
ing, after which they are crushed between rollers and afterwards dri^d. 
The steaming process is a typical one for various other cereals, though 
in some cases the heating consists in baking or kiln drying. 

The effect of the preliminary cooking on the finished product varies 
somewhat according to whether dry or moist heat has been applied, and 
is chiefly noticeable in the altered character of the carbohydrates. In 
all cases the starch is rendered more soluble, whether by the conversion of 
a portion into dextrin and dextrose, or by a simple breaking down 
of the starch grains, as in the case of bread in baking. 

In spite of the seemingly endless variety of the package cereals, they 
divide themselves as a matter of fact into a very few well-defined classes, 
the members of which differ but little from each other except in name. 

First there are the raw cereal grains of the oat, wheat, and corn, pre- 
pared by simple crushing to various degrees of fineness, after decorticating; 
next comes the classes of partially cooked preparations of each of these 
grains, appearing in various forms of "flakes," "granules," "puffs," 
etc., and again a class known as malted cereals, in which the moist, ground 
grain is mixed with malted barley, and, by controlling the temperature, 
a portion of the starch is converted to maltose and dextrin., after which 
the mixture is crushed between hot rollers and dried. 

In the preparation of most of the corn breakfast products, such as 
samp and hominy, it is customary to remove the germ, which contains 
the oil and fat, lest the tendency of the latter to become rancid should 
result in the deterioration of the food. In wheat foods the germ is less 
often removed, and rarely, if ever, in oat preparations. The amount 
of fat found in the prepared cereal food as compared with that in the 
whole grain is of interest in this connection. 

Composition of Some of th,e Common Breakfast Cereals.— The analyses 
below by Baird * will serve to typify the various classes of these prepara- 
* N. Dak. Agric. Exp. Sta., Spec. Bui. Food Dept., 3, 1915, p. 395. 



CEREALS, VEGETABLES, ERUITS, AND NUTS. 



371 



tions as they appear on the market. Where more than one sample was 
analyzed the samples were of different brands of the same or different 
■manufacturers: 



AVERAGE COMPOSITION OF BREAKFAST FOODS (BAIRD). 



No. of 
Anal- 
yses. 



Water. 



Protein 
NX6.25 



Fiber. 



Nitrogen 

free 
Extract. 



Fat. 



Ash. 



Fuel 
Value 
per Lb. 

Cal. 



Wheat Products: 

Farina 

Rolled Wheat 

Shredded Wheat .... 

Flaked Wheat 

Puffed Wheat 

Oat Products: 

Rolled Oats 

Corn (Maize) Products: 

Hominy 

Corn Flakes 

Corn Puffs 

Miscellaneous: 

Force 

Grape Nuts 



8.10 

8.97 
6.30 
6.8s 
6.99 

6.55 

9.48 
5 42 
6-33 

6. 17 
2-59 



o. 22 
2. 26 
1. 91 

1-45 
2. 12 



36 1.38 



0.41 
0.38 
0.96 

0.91 
1.63 



80 



1.78 
1 .40 
1. 17 
2.06 

6.49 



•43 
.82 



0.58 

1-59 
1 .62 
2.65 
1.40 



0.56 I 0.39 
0.25 i 2.76 

0.31 ! 0.50 



307 
1.80 



1719 
1562 
1709 
1685 
1712 

1832 

1683 
1692 
1723 

1705 
1769 



The methods of analysis employed for these preparations are the 
same as for ordinary cereals (p. 285), the sample being ground fine enough 
to pass through a i-mm. sieve. 



PREPARED FOOD FOR INFANTS AND INVALIDS. 

In dealing with the composition and analysis of this class of proprie- 
tary foods more than ordinary care is necessary, in view of the fact that 
one or another of these preparations is frequently prescribed for the 
exclusive diet of those whose very life may depend on the character and 
suitability of the food to the case in hand. Many of these foods do, as 
a matter of fact, honestly fulfil the claims of their manufacturers, but 
others fall far short of so doing, so that it is hardly safe to use them unless 
some intelligent idea of their composition can be gained. It is not, as 
a rule, within the province of the analyst to furnish an opinion regarding 
the adaptability of a certain food to the requirements of an infant or 
invalid, but rather to provide the necessary data whereon such an opinion 
may be intelligently based. 



372 FOOD INSPECTION AND ANALYSIS. 

A simple statement of moisture, fat, protein, carbohydrates (by dif- 
ference), and ash, which in the case of ordinary foods would often be 
sufficient, would be obviously inadequate in expressing the analysis of 
an infant food, since it is of much more vital importance than in other 
foods to know the solubility of the food itself, and, to as great an extent 
as possible, the character of the carbohydrates. 

The chief ingredients of many of these preparations are wheat or 
mixed cereals high in starch. Many of the foods are, according to the 
directions, to be used practically without cooking, but by simply mixing 
with milk or water, and, in some cases, bringing to the boiling-point. 
Hence the degree of conversion which the raw starch has undergone in 
the process of manufacture of the food should, if possible, be ascertained 
as a prime factor in judging of its character and adaptability to the needs 
of the young child and of the sick. Incidentally it should be said that 
few if any of the infant foods, even those whose high character has long 
been established by continued trial, conform very closely to the composi- 
tion of woman's milk, which was long accepted as the true standard on 
which to base their efficiency. Hence it is no easy task to pass judgment 
on a particular food from its chemical composition alone without trial, 
nor is it right to unqualifiedly condemn in all cases food high in insoluble 
carbohydrates, since there are undoubtedly many instances in which 
such foods are successfully used. 

Preparation. — The soluble farinaceous foods are usually prepared 
somewhat as follows: A mixture of ground wheat and barley malt (with 
sometimes a little wheat bran) is mixed with water to form a paste, and 
a little bicarbonate of potash r.dded. The mixture is heated at 65° C. for 
sufficient time to convert the starch, after which it is exhausted with warm 
water, the extract being strained, and the filtrate evaporated to dryness 
to form the food. The sugars of such foods consist largely of maltose 
mixed with dextrin. 

The farinaceous foods, which depend for the conversion of their starch 
on the method of cooking or heating before serving, are usually mixtures 
of wheat or other cereal flour with malt or pancreatic extract. 

The milk foods are variously prepared, either by the simple desicca- 
tion of cow's milk (usually previously skimmed), or, when whole milk 
is used, by mingling the desiccated milk with sugars or baked cereal 
flour. Sometimes desiccated milk is used in mixture with a dried extract 
of malted cereals. In fact all sorts of mixtures are found on the market, 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



373 



involving, however, in nearly all cases, one modification or another of 
the above general processes of preparation. 

Composition. — Few complete analyses of these classes of foods have 
recently been made. Among the best are those of McGill,* from whose 
work the following figures have been selected, illustrating typical examples 
of foods on the market. 



Robinson's Patent Barley... 

Ridge's Patent Food 

Mellin's Infant Food 

Gristle's Food 

Benger's Food 

Allenbury's Malted Food.. . 

Horlick's Malted Milk 

Nestle's Food 

Allenbury's Milk Food No. i 
Allenbury's Milk Food No. ; 

Lactated Food 

Wampole's Milk Food 

Ekkay's Albuminized Food.. 



Num- 
ber of 
Anal- 
yses. 



Water. 



9 8 
9 6 
3 O 
S 8 
8.0 
S3 
3 I 



Pro- 
tein 
NX 
6.25. 



7 o 
13 2 
10.8 

6.8 
II. 7 
lo. I 
14.8 
Ii-S 



Total 
Car- 
bohy- 
drates. 



Cold 

Water 

Extract. 



81.6 
76.0 
82.8 
83.2 
79.1 
83.1 
70.9 
80.2 
65.9 
68.4 
83.6 
72.0 
87.9 



Starch 
etc. by 
Diflfer- 
ence. 



Q + 


76 


9t 


74 


4 




4* 


46 


9 


67 


3t 


6S 


3* 




8* 


LS 


.■? 




5* 





0* 


S3 


6 




8t 


35 



Fat. 



0.9 
0.8 



0.3 
0.7 
8.0 



Ash. 



Kind 

of 

Starch. 



Barley 

Wheat 

None 

Wheat 

Wheat 

Wheat 

None 

Wheat 

None 

None 

Wheat 

None 

Arrowroot 



* Two analyses. 



t One Analysis, 



Street f in 1907 -1908 analyzed single samples found on sale in Con- 
necticut, representing most of the products since analyzed by McGill, 
but those included in the following table were not apparently found on 
sale in Canada in 1914. The figures for water extract and starch (direct 
determination) are not strictly comparable with those for cold water 
extract, starch, etc. (by difference) as obtained by McGill. 





Water. 


Pro- 
tein 
NX 
6.25. 


Fiber. 


Nitro- 
gen- 
free 
Ex- 
tract. 


Reduc- 
ing 
Sugar 

as 
Dex- 
trose. 


Starch 


Water 
Ex- 
tract. 


Fat. 


Ash. 


Kind 

of 

Starch. 




5 9 
5 4 
3 I 
2 S 


13.1 
13 4 
12 3 

II. 4 


I 
0.2 
o.S 


80.1 
71.7 
81.0 
80.9 


37.1 
18.8 
SI. 4 


74.0 
0.6 

16.2 
2.8 


3 3 

88.4 
48.9 
79.7 


0.4 
6.1 
1. 1 
2.3 


o.S 

3-2 

2.0 
2.9 


Wheat 
None 


Borden's Malted Milk, . . . 
Carnrick's Soluble Food . 
Carnrick's Lacto-preparata 



Diabetic Foods. — Gluten flour and similar preparations are primarily 
intended for the use of diabetics, from whose dietary carbohydrates must 
be excluded. 



* Canadian Dept. of Inland Rev., Bui. 278, 1914. 
t Conn. Agric. Exp. Sta. Rep., 1907-8, p. 599. . 



374 



FOOD INSPECTION AND ANALYSIS. 



The following analyses of commercial gluten preparations were made 
by Woods and ^lerrill.* 



"Cooked gluten" 

Whole-wheat gluten . . 

"Glutine" 

Breakfast cereal gluten 
Plain gluien flour .... 
Self-raising flour 




Many brands of gluten flour are put on the market by dealers in so- 
called " health foods," and in many cases are represented to be practically 
free from starch. Thirteen samples of gluten flour were analyzed by 
the author in 1899, varying in price from 11 to 50 cents per pound. Of 
these, 3, the product of one manufacturer, contained less than i^ of 
starch, 3 contained from 10 to 2o9c, while 7 contained from 56 to 70*^^ 
of starch, the substance which, of all others, the diabetic patient tries 
to avoid. Some of these preparations were little more than whole- wheat 
flour. An analysis of one of them, known as " Pure Vegetable Gluten," 
and sold for 50 cents per pound, and of two similar diabetic flours re- 
ported by Winton, follows: 

'• Pure Vegetable " Diabetic " Diabetic 

Gluten." Food." Flour." 

Moisture 10.78 12.67 9.26 

Ash 2.20 0.43 1.30 

Fat 3.25 0.90 2.21 

Protein 14-25 11.37 14-25 

Crude Fiber 0.25 i .03 

Sugars I - 70 1 

Dextrin 2.551 71-51 66.63 

Starch 5^-55 J 

Undetermined 8.72 2.87 5.32 



100.00 



100. CO 



100.00 



Analyses of other preparations have been reported by Street f and 
vIcGill.t 



* Maine Exp. Sta. Buls. 55 and 75. 

t Conn. Agric. Exp. Sta. Rep., 191 2, p. 107. 

X Lab. Inl. Rev. Dept. Canada, Bui. 354, 1916. 



CEREALS, VEGETABLES, FRUITS, AND NUTS. 



375 



Winton has reported the following analyses of flours and meals well 
suited for the preparation of diabetic biscuit, and of the biscuit made 
from two of these by a cook in the family of a diabetic patient: 



Gluten flour 



Gluten biscuit. 



In original 

Calc. water-free. 

In original 

Calc. water-free. 

In original 

Calc. water-free. 



Soja bean meal 

Soja bean biscuit { r- ^ . 



Calc. water-free. 

Casoid flour I r^ , ° ': ' : ' 

Laic, water-free. 



Almond meal . . 



25-58 

7-75 
27.66 



In original j 8.51 

Calc. water-free. . . 1 



0.24 

2-35 
3.16 

4-38 
4-75 
5-33 
7-37 
2.46 

2-73 
6.42 

7.02 



85-38 
95.00 

50-91 
68.41 

39-87 
43.22 
16.71 
23.10 

85-56 
95.08 
50.62 

55-32 






























J3 










Sf^ 






&H 














•a 
a 


i3W 


^ 















•z 


u* 





-03 


3-69 


0.56 





-03 


4. II 


0.62 





.64 


3-18 


17-34 





.86 


4-27 


23-30 


3 


-85 


25.09 


19.06 


4 


-17 


27.20 


20.66 


I 


-55 


12.84 


35-91 


2 


.14 


17-75 


49-64 
0.50 

0-56 
15-63 






2 


.86 


15.96 


3 


.12 


17-45 


17.09 



n! n 

bo-" 



46 
96 



8-95 
9.70 



none 
none 



.18 
■85 



In the analysis of diabetic foods, the determination of starch, sugar 
and dextrin together is of greater value than of starch alone, since all 
three classes of carbohydrates are about equally injurious to diabetics, 
the starch and dextrins being converted into sugars by the digestive 
fluids. The nitrogen-free extract of cereal preparations corresponds 
closely with the sum of the starch, sugar and dextrin, but in the case 
of soja bean meal, almond meal and other products of legumes and oil 
seeds, as well as vegetables, it is considerably greater, as it includes 
pentosans and other substances. 



METHODS OF ANALYSIS. 

Preparation of the Sample.— Grind sufficiently fine in a mortar or 
mill to pass through a i-mm. sieve. 

Determination of Water, Protein, and Ash.— Follow the regular methods 

for cereal products (pages 285-287). 

Determination of Fat. — Owing to the presence of gelatinized starch, 
sugars, and similar incrusting constituents direct ether extraction is usually 
not admissable. Proceed as with bread, page 343. 



376 FOOD INSPECTION AND ANALYSIS. 

Separation of the Carbohydrates can be effected by Stone's method 
(pages 304, 305), but a very satisfactory idea of the solubility of these 
foods, which is of chief importance, can be gained by the determination 
of the cold water extract and reducing sugars. 

Determination of Starch, Sugar, and Dextrin.— Determine together 
in diabetic preparations by the diastase method (page 292) omitting the 
preliminary washing with dilute alcohol. The results thus obtained with 
cereal products agree fairly well with the nitrogen-free extract calculated 
by difference in the usual manner, but this is not true of meal or biscuit 
made from soy beans, almonds, etc. 

Determination of Cold-water Extract— McGill Method*— Weigh the 
equivalent of 10 grams of the moisture-free substance, finely ground, 
into a tared flask, and add water in several portions with gentle shaking 
till the contents of the flask weigh no grams. Cork the flask, then vig- 
orously shake at intervals during 6 or 8 hours and allow to stand over 
night. Decant the supernatant liquid into the large tubes of a centrifuge 
and whirl till the sediment settles out. Filter the comparatively clear 
liquid, transfer 20 cc. of the filtrate, corresponding to 2 grams of the 
original sample, to a tared dish, evaporate to dryness and dry to constant 
weight, as in the determination of the total solids. 

Additional information may be gained from the specific gravity of 
the 10% solution of the cold-water extract, best obtained by means of a 
pycnometer. 

Determination of Reducing Sugars. — Determine in an aliquot part 
of the above 10% solution, diluted to proper strength. 

Effects of Subsequent Heating. — It is hardly fair in the case of those 
farinaceous foods which, according to directions, are to be subsequently 
subjected to heating, or boiling with water or milk, to condemn them as 
containing much insoluble matter, without comparing the figures express- 
ing results of the analyses of the raw foods, calculated to the water- free 
basis, with those obtained on analyzing the food after boiling or otherwise 
cooking with pure distilled water, for a length of time specified in the 
directions, and afterwards drying. It is possible that the presence in 
the food of diastase, or other ferment, may be depended on to hydrolyze 
a whole or a portion of the starch, and only by such comparison will this 
be shown. 



Lab. Inl. Rev. Dept. Canada, Bui. 59, if 



CEREALS, VEGETABLES, FRUITS, AND NUTS 377 

Microscopical Examination of the food is of value in determining 
its general character, showing especially whether or not starch is present 
in its original form, or has been converted in whole or in part. The par 
ticular varieties of cereal grain employed are generally evident, as well 
as the presence and proportion of the different tissues of the grain! 



CHAPTER XI. 

TEA, COFFEE, AND COCOA. 
TEA. 

Nature and Classification. — Tea consists of the prepared leaves or 
leaf buds of Camellia Thea also known as Thea chinensis. 

The best teas are made from young leaves only, the Chinese teas 
being classified with reference to the age and position of the leaf on the 
young shoot. Thus, the very choicest Chinese tea, rarely found outside 
of China, is prepared from the youngest or end leaves of the shoot, which 
are scarcely more than buds, and form the tea known as pekoe tip, or 
flowery pekoe. The next leaves are the orange pekoe and pekoe, which 
produce a very high grade of tea, while next in order as to age, size, and 
grade of leaf are the souchong ist and 2d, and the congou, producing 
teas called by the same names. 

More than 50% of the tea consumed in the United States comes from 
China, and over 40% from Japan, the remainder being derived largely 
from India, Ceylon, and other East Indian ports. 

In the manufacture of tea the fresh leaves, which are nearly 80% water, 
are rolled, withered by exposure to light, heat, and air, and finally dried 
or "fired" by treatment with artificial heat over charcoal fires, or in 
properly constructed furnaces. 

Teas are divided into two groups, black and green, which differ from 
each other, not as formerly supposed in being derived from different plants, 
but in their process of manufacture, the same species of plant furnishing 
both varieties. Genuine green tea is prepared by first steaming and 
afterwards drying the leaves while still fresh, thus retaining the bright 
color. Black tea is allowed to undergo oxidation or fermentation by 
exposure to the sun, which gradually turns the leaves black. Less tannin 
is present in black tea than in green. 

378 



TEA, COFFEE, AND COCOA. 



379 



Composition of Tea. — Konig gives the following composition of fully 
developed tea- leaves, being the mean of 50 to 70 analyses : 



j 1 
1 Nitroge- ! 
Water, nous Sub- Theine. 
; stances. 


Essential 
Oil. 


Fat.Chlo- 

rophyl, 

and Wax. 


Dextrin, Tannin. ^^^^'"■ 
etc. 1 ^^'^• 


Crude 
Fiber. 


Ash. 


9-51 


24-50 3-58 


0.68 


6-39 


6.44 


15-65 


16.02 


11.58 


5-65 



Though the nitrogenous substances of tea predominate in amount 
over any other class of constituents, yet, with the exception of theine or 




Fl«. 72. — a, Flowery Pekoe; h, Orange Pekoe; c, Pekoe; d, Souchong, ist; e, Souchong, 2d; 
/, Congou; a, b (when mixed together), Pekoe; a, b, c, d, e (when mixed together). Pekoe 
Souchong. If there be another leaf below /, it is termed Bohea. At base of leaves 
are buds i, 2, 3, 4, from which new shoots spring. (After Money.) 

caffeine, they have been little studied. Theine, tannin, and essential 
oil give to the infusion of tea its chief characteristics. 

Zollinski * gives the following summarized results of analyses of a 
number of the cheaper grades of Chinese black tea: 



* Zeits. anal. Chem., 1898, 37, 365. 



380 



FOOD INSPECTION AND ANALYSIS. 



Water. 



Total 
Nitrogen. 



Albumin- 
oid and 
Amido- 

nitrogen. 



Protein, 
NX6.2S. 



Theine. 



Ash. 



Soluble 
Ash. 



Insoluble 
Ash. 



Maximum. 
Minimum . 
Average 



11-57 

9.96 

10.58 



4.12 
3-76 
3-93 



3-78 
3-37 
3-52 



23-83 
21.06 



2.06 
1. 14 
1-55 



6.78 
4-79 
5-94 



31-17 
28-13 
29.67 



61.03 

57-74 
59-75 



A very complete series of analyses of tea was made by Joseph F. Geiss- 
ler in 1884,* from which the following summaries are taken: 







eg 


1 

to 


It 


4J 




c 
'S 

G 


c 


Hx. 




2 








^< 


S 


w« 




£^ 




^ 


^< 


&< 


G< 


u5 C 


Indian: 


Maximum. . 


6 


6.1939-66 


45-64 


53-07 


18.86 


3-3 


5-79 


3-68 


2.22 


.296 




Minimum . . 




5-56,37-80 41-32148-53 


13-04 


1.8 


5-42 


3-24 


1-93 


-137 




Average. 




S-81 


38.7742.94 


51-24 


14-87 


2-7 


5.62 


3-52 


2.12 


.178 


Oolong: 


Maximum. . 


13 


6.88 


44.0248.87 


53-15 


20.07 


3-50 


6. II 


3-71 


3-17 


.838 




Minimum . . 




5-09 


34.10I40.6 


44-8 


11-93 


I -15 


5-44 


2.60 


1.84 


.266 




Average 




S-89 


37-8843-32 


50-7 


16.38 


2.32 


5.81 


3-2 


2.68 


-507 


Congou: 


Maximum.. 




9-15 


32.1437.06 


63-85 


13.89 


2.87 


6.48 


3-52 


3-86 


1-31 




Minimum . . 




7-65 


23.48127.48 


54-5 


8.44 


1.70 


5-52 


2.28 


1.90 


-32 




Average 




8.37 


28.4034.35 


57-2 


11-54 


2-37 


5-75 


3.06 


2.68 


■425 



Kenrick f gives the following averages of a series of analyses of tea 
made by him in 1891: 



Congou tea. — 

Assam tea 

Ceylon tea . 

Unclassed black 

Japan 

Gunpowder . . . 
Young Hyson. . 



O t/l 

IS 



10 
3 



13 



Substances Extracted 

by 10 Minutes' 

Infusion. 



23- 
38. 
27. 

23- 
30. 

28. 

34- 



-37 


5- 


-53 


7- 


-45 


7- 


.76 


5- 


.07 


9- 


-55 


8. 


.22 


10. 



-65 



2.82 

2-45 
2-39 
2.52 



3-55 
3-69 
3-34 
3-53 
3.62 

3-36 
3-83 



2.2» 
2.16 

1.88 
2-37 
2-73 
3-70 
2.1C 



83 



4-51 
3-81 
3-50 



The ash of many genuine teas has been examined by Battershal t 
with the following results: 

* Am. Grocer, Oct. 23, 1884. 

■\ Canada Inland Rev. Dep. Bui. 24. 

X Food Adulteration and its Detection. 



TEA, COFFEE, AND COCOA. 



381 





Oolong. 

Average of 5° 

Samples. 


Japan. 


Spent 
Black Tea. 


Total ash 


6.04 

3-44 
57.00 


5-55 
3.60 

64.55 


2.52 
28 


Soluble in water 


Per cent soluble 









Silica 

Chlorine 

Potash 

Soda 

Ferric oxide 

Alumina 

Manganic oxide. 

Lime 

Magnesia 

Phosphoric acid. 
Sulphuric acid . . 
Carbonic acid. . , 



COMPOSITION. 



11.30 

1-53 

37-46 

1.40 

1.80 

5-13 
2. 10 

9-43 

8.00 

12.27 

4.18 

5-40 



9-30 

1.60 

41.63 

I. 13 
I. 12 

4.26 

1-30 
8.18 

5-33 
16.62 

3-64 
5-9° 



27.75 
0.79 



16.00 

19.66 

11.20 

15.80 

1. 10 

6.70 



99.00 



Kozai * gives the following as the results of analyses made by him of 
Japanese teas: 



Unprepared 
Leaves. 



Caffeine or theine 

Ether extract 

Hot-v/ater extract 

Tannin (as gallotannic acid) 
Other nitrogen-free extract . 

Crude protein 

Crude fiber 

Ash 

Albuminoid nitrogen 

Caffeine nitrogen 

Amido-nitrogen 

Total nitrogen 



3-3° 
6.49 

50-97 
12.91 
27.86 

37-33 
10.44 

4-97 
4. II 
0.96 
0.91 
5-97 



Green 
Tea. 



3.20 

5-52 

53-74 

10.64 

31-43 
37-43 
10.06 

4-92 
3-94 
0-93 
1-13 
5-99 



Black 
Tea. 



3-30 
5.82 

47-23 
4.89 

35-39 
38.90 
10.07 

4-93 
4. II 
0.96 
1. 16 
6.22 



PROXIMATE COMPONENTS AND ANALYTICAL METHODS. 

Preparation of Sample. — Grind the material so as to pass a sieve 
with holes 0.5 mm. in diameter. 

Moisture, Ether Extract, and Crude Fiber are determined in the 
same weighed portion of 2 grams, by methods described under cereals (p. 
285). Acidity determination by hydrogen electrode is described on p. 1035. 



Bui. 7, Imperial College of Agriculture, Japan. 



382 FOOD INSPECTION AND ANALYSIS. 

Determination of Protein.— Determine total nitrogen by the Kjeldahl 
or Gunning method; from this subtract the nitrogen due to caffeine 
(obtained by dividing by 3.464) and multiply the difference by 6.25. 

Determination of Total Ash. — Burn 2 grams of the material to a 
white ash in a platinum dish at a faint red heat. The total ash of pure 
tea should not be less than 4 nor more than 7'^"^. 

Determination of Soluble and Insoluble Ash.^Transfer the total 
ash, as obtained above, to a beaker with 50 cc. of hot water, boil, collect 
the insoluble ash on a Gooch crucible, wash with hot water, dry below 
redness, and weigh. To obtain the soluble ash subtract the insoluble 
from the total ash. 

Determination of Ash Insoluble in Acid. — Proceed as in the deter- 
mination of water-insoluble ash, using, however, 25 cc. of 10% hydro- 
chloric acid instead of water for the boiling. 

Determination of Alkalinity of Ash.* — This is expressed in terms of 
cc. of tenth-normal acid required for the ash of i gram of sample. 

Soluble Ash. — Cool the filtrate from the determination of insoluble 
ash, as described above, and titrate with tenth-normal hydrochloric acid, 
using methyl orange as an indicator. 

Insoluble Ash. — Add excess of tenth-normal hydrochloric acid (usually 
10 to 15 cc.) to the ignited insoluble ash as obtained above in the platinum 
dish, heat to the point of boiling over an asbestos plate, cool, and titrate 
excess of hydrochloric acid with tenth-normal sodium hydroxide, using 
methyl orange as an indicator. 

Determination of Essential Oils. — Distil 100 grams of the tea with 
800 cc. of water, and shake out the distillate with several portions 
of ether. The residue from the combined ether extracts contains the 
volatile oil. 

Determination of Insoluble Leaf. — Winton, Ogden, and Mitchell 
Method.-\ — Boil 2 grams of the unground tea for 30 minutes with 200 cc. 
of water, taking care to so adjust the flame as to avoid appreciable con- 
centration. Collect the insoluble leaf on a tared filter, d?y on a watch 
glass until no moisture is apparent, then transfer to the weighing bottle 
and complete the drying in a boiling water-oven. If the amount of 
insoluble leaf is above 60^, the presence of spent or exhausted leaves 
may be suspected. 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 69. 
t Conn. Exp. Sta. Ann. Rep., 1898, p. 132. 



TEA, COFFEE, AND COCOA. 



383 



Doolittle and Woodruff * boil for i hour, but in other respects follow 
the above method. 

Determination of Extract. — By this term is meant the total amount 
of water-soluble matter in tea, including such compounds as tannin, 
caffeine, albuminous matter, dextrin, gum, certain parts of the ash, etc. 

The value of a tea from a food standpoint depends obviously upon 
the character and amount of the extract, rather than on the composition 
of the dry tea. The relative composition of the extract and of the in- 
soluble leaf, as found by Eder, is given in the following table: 





Extract. 


Insoluble 
Leaf. 


Dry matter 


Per Cent. 
40. 
12. 


Per Cent. 
60. 
12.7 

7-2 

10. 

2-3 

0.29 

0.58 
1.03 
0.68 


Nitrogenous substances 


Theine 

Tea oil 


2. 
0.6 


Resin, chlorophyll, etc. 


10. 
12. 

1-7 

C.94 
0.04 
0.13 
0.21 


Tannin 


Extractives 


Ash 


Potash 


Lime 


Phosphoric anhydride 

Silica 



The sum of the percentages of insoluble leaf and moisture subtracted 
from 100 gives the percentage of extract. 

Determination of Tannin. — Lowenthal- Proctor Method.^ — i. Reagents: 

{a) Potassium permanganate solution containing about 1.33 grams 
per liter. 

Q}) Tenth-normal oxalic acid solution (6.3 grams per liter) . 

(c) Indigo carmine solution, containing 6 grams indigo carmine (free 
from indigo blue) and 50 cc. concentrated sulphuric acid per liter. 

{d) Gelatin solution, prepared by soaking 25 grams gelatin for an 
hour in a saturated sodium chloride solution, heating till the gelatin is 
dissolved, and making up to a liter after cooling. 

(e) Mixture of 975 cc. saturated sodium chloride solution and 25 
cc. concentrated sulphuric acid. 

(/) Powdered kaolin. 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 150, 1907, p. 48. 

t Jour. See. Chem. Ind., 3, 1884, p. 82; U. S. Dept. of Agric, Div. of Chem., Bui. 13, 
)2, p. 890. 



384 FOOD INSPECTION AND ANALYSIS. 

Obtain the value of the potassium permanganate solution in terms 
of the tenth-normal oxalic acid solution. 

2. Process. — Boil 5 grams of the powdered tea for half an hour with 
400 cc. of water, cool, and make up to 500 cc. in a graduated flask. To 
10 cc. of the infusion (filtered if not clear) add 25 cc. of the indigo car- 
mine solution and about 750 cc. of water. Then add from a burette 
the potassium permanganate solution, a little at a time while stirring, 
till the color becom'^s light green, then cautiously drop by drop till the 
color changes to bright yellow, or further to a faint pink at the rim, 
matching in any event the color adopted in standardizing. The volume 
in cubic centimeters of permanganate furnishes value a of the formula. 

Mix 100 cc. of the clear infusion of tea with 50 cc. of gelatin solution, 
100 cc. of salt acid solution, and 10 grams of kaolin, and shake several 
minutes in a corked flask. After settling, decant first the clear super- 
natant liquid through a filter, and finally bring the precipitate upon the 
filter. Mix 25 cc. of the filtrate (corresponding to 10 cc. of the original 
infusion) with 25 cc. of the indigo carmine solution, and about 750 cc, 
of water, and titrate with permanganate as before. The volume in cubic 
centimeters of permanganate used gives value h. 

a = quantity of permanganate solution required to oxidize all oxidiz- 
able substances present. 

6 = quantity of permanganate solution required to oxidize substances 
other than tannin. 

.'. a — b = c, permanganate required for the tannin. Assuming that 
0.04157 gram tannin (gallotannic acid) is equivalent to 0.063 gram oxalic 
acid, the tannin in the tea h readily calculated. 

As recommended by Doolittle and Woodruff* the determination 
may be conveniently made on aliquot portions of the solution obtained 
in the determination of insoluble leaf. 

Method of Fletcher and Allen.-\ — This method depends upon the pre- 
cipitation of the tannin and other astringent matters in tea infusion by 
lead acetate, the point of complete precipitation being indicated by an 
ammoniacal solution of potassium ferricyanide. 

Five grains of neutral lead acetate are dissolved in water, made up to 
I liter, and after standing the solution is filtered. 

As an indicator, 0.05 gram of pure potassium ferricyanide is dis- 
solved in 50 cc. of water, and an equal volume of concentrated ammonia- 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 105, 1907, p. 49. 
t Chem. News, 29, pp. 169, 189. 



TEA, COFFEE, AND COCOA. 385 

water is added. This indicator produces a red coloration with tannin, 
gallic acid, or gallotannic acid in solution, being so sensitive that 
a drop of the indicator will detect i part of tannin in 10,000 parts of 
water. 

Three separate quantities of 10 cc. each of the standard lead acetate 
solution, as above prepared, are measured into as many beakers, and each 
diluted to 100 cc. with boiling water. Two grams of powdered tea are 
boiled in 250 cc. of water, and varying quantities of this decoction are 
measured from a burette or pipette into the beakers containing the lead 
solution, the first beaker receiving, say, 12 cc, the second 15 cc, and 
the third 18 cc, in the case of black tea, and, with green tea, 8, 10, and 
12 cc, respectively. 

About I cc of each of these trial quantities is removed from the 
various beakers by means of a pipette, passed through small filters, and 
tested with the ammoniacal ferricyanide indicator, the drops of filtered 
solution being allowed to fall directly on spots of the indicator, previously 
placed on a white slab or plate. 

It is thus easy to ascertain the approximate amount of tea solution 
which it is necessary to add to produce a pink coloration with the indi- 
cator, so that by repeated tests, nearly the right amount may be added 
at once. If no coloration in a given case is produced when a drop of 
the filtrate from the solution in the beaker is allowed to fall on the drop 
of indicator solution, a little more of the tea decoction is added, and this 
process is repeated until the pink color is apparent. 

It should be noted how much of the tea decoction is necessary to add 
to 100 cc of pure water, that a drop of the solution may produce the pink 
coloration with the ferricyanide, and this amount should be subtracted 
from the amount of decoction found necessary to add to the known lead 
solution in the beaker. It was found by repeated experiment that 10 cc 
of lead solution would precipitate 0.0 1 gram of pure gallotannic acid; 
hence, carrying out the process exactly as above described, 125 divided 
by the number of cubic centimeters of tea decoction required gives the 
percentage of tannin in the sample.* 

Theine or Caffeine (C8H10N4O2). — This alkaloid when pure exists 
in white silky needles. It is odorless and sparingly soluble in cold water, 
but more so in hot. It is less soluble in alcohol, and almost 
insoluble in ether. It readily dissolves in chloroform. It is present 



* This process estimates the total astringent matter, all of which is counted in as 
tannin. 



386 FOOD INSPECTION AND ANALYSIS. 

in tea, coffee, and kola. Graf* has shown that the amount of caf- 
feine present in tea is in most cases proportional to the commercial 
value and quality. 

Detection. — Caffeine may be detected, if present in a suspected residue, 
by the so-called " murexid test," which is made with the material in a 
solid state, or with the residue from the evaporation of a liquid. A small 
quantity of the solid or powdered material is heated in a white porcelain 
dish and covered with a few drops of strong hydrochloric acid, after which 
a fragment of potassium chlorate is immediately added. The mixture 
is then evaporated to complete dryness on the water-bath, whereupon, 
if caffeine is present, a reddish-yellow or pink color is produced. After 
coohng, the residue is treated with a very little ammonia water 
apphed on the point of a stirring-rod. In the presence of caffeine, a 
purple color (that of murexoin) is produced on application of the 
ammonia. 

Determination of Theine or Caffeine. — Dvorkovitsch Method. ■\ — 
Digest ID grams of the powdered tea with 200 cc. of boiling water for 
5 minutes and decant the solution; repeat the treatment twice, and boil 
the residue with 200 cc. of water. Make up the combined solutions to 
1000 cc. and extract a portion with petroleum ether to remove fat, etc. 
To 600 cc. of the fat-free solution (equivalent to 6 grams of tea) add 100 
cc. of 4% barium hydroxide solution, mix and filter. To 583 cc. of the 
filtrate (equivalent to 5 grams of tea) add 100 cc. of a 20% solution of 
sodium chloride, and extract three times with chloroform. Distil the 
greater part of the chloroform from the combined extracts, place the 
residue in a tared dish, evaporate the remainder of the chloroform, dry 
at 100° C, and weigh. The caffeine is usually of sufficient purity to 
render a nitrogen determination unnecessary. 

Doolittle and WoodruffX proceed as follows: Extract in a separating 
funnel with petroleum ether 225 cc. of the filtrate from the determi- 
nation of insoluble leaf (p. 382) made up to 500 cc. To the fat-free 
portion add 50 cc. of a 4% barium hydroxide solution, shake well, and 
filter. To the filtrate add 50 cc. of a 20% sodium chloride solution and 
proceed as above described. 



* Forsch, Ber., 4, 1897, pp. 88, 89. 

fBer. d. chem. Ges., 24, 1891, p. 1945; U. S. Dept. of Agric, Bur. of Chem., Bui. 107 
(rev.), p. 150. 
X Loc. cit. 



TEA, COFFEE, AND COCOA. 387 

Stahhchmidt Method * Modified by Spencer. '\ — Boil gently 5 grams 
of the ikicly po.vdered tea in a flask with 420 cc. of water for 30 minutes, 
cool, add sufficient lead subacetate (solution or powder) to remove pre- 
cipitable substances, make up to 500 cc, and filter through a dry paper. 
Delead an aliquot of 400 cc, equivalent to 4 grams, with hydrogen sul- 
phide, • boil off the excess of hydrogen sulphide, filter, wash with hot 
water, and evaporate the filtrate to about 50 cc. Shake out the solution 
in a separatory funnel with several portions of chloroform until all the 
theine has been extracted, evaporate off the chloroform from the com- 
bined extracts in a tared flask, and dry the theine 2 hours or to constant 
weight at 75° C. 

Bartlett J has found that the Stahlschmidt method in essentially the 
form given by Spencer gives satisfactory results. 

Facing. — The most common form of tea adulteration, if such it may 
be called, is the practice of " facing " the dried leaves, or treating them 
with certain pigments and coloring materials to impart a bright color 
or gloss to the tea, thus causing an inferior grade to appear of better 
quality than it really is. This practice is more often applied to green 
tea. The materials for facing include such substances as Prussian blue, 
indigo, plumbago, and turmeric, often accompanied by such minerals 
as soapstone, gypsum, etc. Only a small amount of foreign material is 
actually added to the tea, but the adulteration consists in the deceptive 
appearance imparted thereto. 

Battershal has examined various samples of the preparations used 
in Japan for facing tea. He found in one case the following compo- 
sition: Soapstone, 47.5%; gypsum, 47.5%; Prussian blue, 5%. An- 
other sample consisted of soapstone, 75%; indigo, 25*^. A third was 
composed of soapstone, 60%, and indigo, 40%. In applying the facing 
to the tea, the latter is first heated in an iron pan over the fire, the facing 
mixture is then added while still hot, and the whole is stirred briskly till 
the desu-ed color is imparted. The Chinese and Japanese do not face 
the tea which they themselves consume, but only that intended for export 
trade. 

Detection of Facing. — The most delicate test for facing is to examine 
under the microscope, or lens, the dust obtained by sifting the leaves or 
the sediment obtained after shaking them with water. Plumbago appears 

* Pogg. Ann., 112, p. 441. 

t Jour. Anal. Chem., 4, 1890, p. 390. 

X Jour. Assn. Off. .A.gric. Chem., 5, 191 7, p. 21. 



388 FOOD INSPECTION AND ANALYSIS. 

glossy black, soapstone gray, gypsum white, Prussian blue, ultramarine 
and indigo shades of blue, and turmeric yellow, Prussian blue is 
decolorized by sodium hydroxide solution. Ultramarine is not affected 
by alkali but is decolorized by hydrochloric acid. Indigo is not decol- 
orized by either reagent. 

Read * rubs the siftings with a spatula on sheets of white and black 
paper and removes the loose dust. The colors after this treatment are 
recognized under the lens as streaks on the paper. West f detects Prus- 
sian blue by the blue spots formed by sprinkling the ground tea on filter 
paper moistened with oxaHc acid solution and drying. 

Prussian blue if present in considerable amount may be detected in 
the sediment, as above obtained, by the blue precipitate which forms 
after dissolving in hot alkali, filtering, acidifying with hydrochloric acid, 
and then adding a drop of ferric chloride. If the residue on the paper after 
treatment with hot alkali, on removal to a porcelain dish and treatment 
with concentrated sulphuric acid, yields hydrogen sulphide (recognized 
by its odor or by the blackening of lead acetate paper) ultramarine is 
indicated. 

Such minerals as gypsum and soapstone are readily separated as a 
sediment by shaking the leaves in water, and the sediment is examined 
by the appropriate qualitative methods for these substances. 

Spent or Exhausted Leaves. — These consist of leaves of tea that have 
been previously steeped or infused, and afterwards rerolled and dried. 
Such leaves are sometimes mixed with tea as an adulterant. Any con- 
siderable admixture of spent leaves is evident, both by the extremely low 
ash, and the abnormally small proportion of water-soluble ash in the 
sample. It is rare that the total ash of genuine tea is under 5%, while 
the soluble ash is seldom less than 3%. 

The ash of spent tea leaves sometimes runs as low as 2.5%, of which 
generally not more than 0,3 to 0.8 per cent is soluble. Spent leaves are 
also naturally low in tannin and in extract. 

If the extract is much below 32%, spent leaves may be suspected. 
Allen determines the per cent of spent leaves by subtracting the per cent 
of extract from 32, multiplying by 100 and dividing by 30. 

The use of spent or exhausted leaves as an adulterant is very rare 
at present, though formerly of common occurrence. 

Foreign Leaves as a Substitute for Tea. — This sophistication is not 
common, but the detection of leaves other than tea is readily accom- 

* U. S. Treasury Decision, No. 32322. 
t Jour. Ind. Eng. Chem., 4, 1912, p. 528. 



TEA, COFFEE, AND COCOA. 



389 



plished by a careful examination of the shape and character of the leaves. 

For this purpose the dried leaves are opened out by soaking a short time 

in hot water, after which they are spread upon a glass plate, and examined 

by the aid of a magnifying-glass. 

The genuine tea leaf (Fig. 73) is very characteristic, and is readily 

distinguished from other leaves. It is oval or lanceolate, 5 to 8 cm. long 

and 2 to 3 cm. wide. It is short-stemmed, 
somewhat thick and fleshy, attenuated at the 
bottom and usually pointed at the top. At a 
certain height from the base, from a third to 
a quarter up, the smooth or wavy border be- 
comes peculiarly, though not deeply, serrated in 
a regular manner, the serrations, which are 
hook-shaped, continuing to the tip of the leaf. 
Mature leaves always show these serrations, 
but they are somewhat obscure in young leaf 
buds. The latter, however, are rarely found 
in this country. The veins extend outward 
from the central rib nearly parallel to each 
other, but before reaching the border, each 
bends upward to form a loop with the one 

above. 

Foreign leaves, said to be used as aduher- 
ants, are those of the willow, poplar, elder, 
birch, elm, and rose, but the writer has never 
found any of these in tea. All of them differ 
materially from the genuine tea leaf, and if 
foreign leaves are apparent in a sample under 
examination, they should be compared with various leaves collected by 
the analyst for the purpose. 

Stems and Fragments.-These, as well as '' tea dust," are apparent 
by an examination of the leaves, opened out in hot water as explamed 
above. The ash of tea stems and dust is abnormally high. 

Besson * and Deuss t oppose fixing a maximum limit for stems on 
the ground that the more expensive sorts often contain more stems than 
the cheaper. This is due partly to methods of gathering and partly to 
the presence of sittings with low stem content in the cheaper grades.^ 

The term " lie tea " is applied to an imitation of tea, consistmg of 




The Leaf of 



Fig. 73 

Genuine Tea 



* Chem. Ztg., 39, 1915, P- 82. t Chem. Weekbl., 13, 1916, p. 66. 



390 FOOD INSPECTION AND ANALYSIS. 

fragments, stems, and tea dust, mixed with foreign leaves, mineral matter, 
gum, etc. The ash of such " tea " has been found as high as 50%. Such 
imitations are now almost unknown. Make-weight substances, such as 
brick-dust, iron salts, metallic iron, sand, etc., have been found in tea. 
If present, they are to be found in the sediment, obtained on shaking out 
the tea in water. 

Added Astringents. — Catechu is sometimes said to be added to tea 
to give it increased astringency, especially to such tea as has been adulter- 
ated by the addition of exhausted tea. Hagar's method for detecting 
catechu is as follows: 

A hot-water extract of the tea (i to 100) Is boiled with an excess of 
litharge and filtered. To a part of the filtrate, which should be perfectly 
clear, nitrate of silver is added. If catechu be present, a yellow floc- 
culcnt precipitate, rapidly becoming dark-colored, is formed. Pure tea 
treated in like manner gives a gray precipitate. 

Spencer * adds, instead of silver nitrate, a drop of ferric chloride to 
the clear filtrate. With catechu a green precipitate is formed. 

As a matter of fact the worst forms of tea adulteration, such as the 
actual substitution of foreign leaves, once so commonly practiced, are 
now extremely rare in this country and have been for some years, by reason 
of the careful system of government inspection in force at the various 
ports of entry. The greater portion of the tea on our market to-day is 
genuine, but fraud is practiced to l considerable extent by the substitu- 
tion of inferior grades for those of good quality. This form of deception 
is in many cases beyond the power of the analyst to detect, and properly 
comes within the realm of the professional tea-taster. 

Tea Tablets. — Finely ground tea of varjdng quality is sometimes 
pressed into tablets, to be used by travelers and campers for preparing 
a beverage, by simply dissolving in hot water. 

The composition of one of these preparations sold under the name 
of Samovar Tea Tablets, analyzed by the Mass. State Board of Health, 
is as follows: 

Water 8.7 

Theine 2.25 

Extract 54.4 

Ash 5.4 

Soluble ash 2.8 

Insoluble ash 2.6 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 885. 



TEA, COFFEE, AND COCOA. 



391 



Microscopical Structure of Tea. — The powdered tea may be examined 
directly in water-mount. Schimper recommends treating the powdered 
tea with chloral hydrate or potash lye, to render it more transparent. 

By far the most characteristic element is the peculiarly shaped 
sclerenchyma, or stone cell, st, Fig. 74, entirely unlike anything to be found 
in other leaves. These cells are very irregular in form, being sometimes 
star-shaped, sometimes branched, almost always with deeply wrinkled sides, 




Fig. 74. — ^Powdered Tea under the Microscope. Xi6o. g, end of leaf nerve; p, chloro- 
phyll parenchyma; st, stone cells; h, hairs. The tissues were warmed in potash to 
render transparent. (After Moeller.) 

and often with sharp points. In most foreign leaves such sclerenchyma 
cells are lacking, but they are abundant in all genuine tea leaves, excepting 
rarely in the very young leaves, where they are sometimes not fully devel- 
oped. They are especially numerous in the main vein and in the stem. 
They may be seen to best advantage in a section of the stem, or midrib, 
made parallel to the surface of 'he leaf. To make such a section, soak 
the leaf first in water, and afterwards dry in alcohol. The interior of 
the leaf is composed chiefly of ground tissue, having rounded cells full 
of chlorophyll grains and the fibro-vascular bundles of the veins. 

Other important characteristics are the peculiar hair growth on the 
under epidermis, B, which is apparent in nearly all teas, also crystal 
rosettes of calcium oxalate, which are nearly always present, even in 
fragments of tea leaves, but not in all foreign leaves. The peculiar 
structure of the lower epidermis, B, with its numerous stomata is also to 
be noted. See Figs. 189 and 190, PI. XVIII. 



392 FOOD INSPECTION AND ANALYSIS. 



COFFEE. 



Nature of Coffee. — Coffee is the seed of the Coffea arabica, a tree 
which, when under cultivation, is not allowed to exceed twelve feet in 
height, but when wild sometimes reaches a height of twenty feet. It is 
indigenous in Southern Abyssinia, and was cultivated in Arabia in the 
sixteenth century, and in the East Indies in the seventeenth, afterward 
being introduced into the West Indies and South America. The coffee- 
beans are usually inclosed in pairs in the berry, being plano-convex with 
their flat sides together but in " pea berry " coffee only a single, rounded 
bean is present. 

When the ripe fruit is gathered, it is first dried and then freed from 
the hulls, usually by machinery, or, in the West Indies, the green berries 
are " pulped " or " hulled " under water by a peculiar macerating machine. 
The raw beans are roasted, and afterwards ground for preparing the 
infusion. 

The principal varieties now on the market are true or Arabian Mocha 
produced in the Yemen district and shipped from the port of Aden, Abys- 
sinian or long berry Mocha, Java produced on the island of Java under 
government supervision, Rio and Santos, the leading Brazilian varieties 
shipped from the ports of Rio Janeiro and San Paulo respectively, Mara- 
caibo a Venezuelian coffee, and Bogota produced in Colombia. Porto 
Rican and other West Indian varieties, also the product produced in 
the islands of the Pacific, often shipped under the name of Java, and 
various African coffees, are of considerable importance. 

Brazil furnishes more than half the world's supply of coffee, and 
nearly 75% of that consumed in the United States. 

Constituents of Coffee. — Most of the coffee in the retail market is 
roasted, being sold either in the whole bean or ground. 

The chief constituents of raw coffee, besides water, are oil, cellulose, 
sugar, pentosans, dextrins, " caff e tannic acid " (chlorogenic and coffalic 
acids), protein, caffeine, coffearine (an alkaloid), and ash. 

During roasting the sugar is largely caramelized, the caffetannic acid 
reduced, the bean rendered less brittle, and certain flavors are developed. 
Various substances have been named as products of roasting. Of these 
caffeol, a volatile oily substance, has long been considered the chief aro- 
matic constituent, but its identity is now disputed. Several authors have 
detected pyridine. There is a slight loss of caffeine during roasting. 



TEA, COFFEE, AND COCOA. 



393 



The following summary of analyses of coffee of various kinds made by 
Konig show in general its composition: 



Raw CofEee. 


Roasted Coffee. 


Minimum. 


Maximum. 


Minimum. 


Maximum. 


8.0 


12.0 


0.4 


4.0 


0.8 


1.8 


0.8 


1.8 


II. 4 


14.2 


10-5 


16-5 


S-8 


7-8 


0.0 


I.I 


i6.6 


42.3 


26.3 


51.0 


I.I 


2.2 


1-3 


2.7 


3-5 


4.0 


4.0 


5-0 



Water 

Caffeine 

Fat 

Reducing sugar, 

Cellulose 

Total nitrogen. 
Ash 



The change in composition that takes place in roasting coffee is well 
shown by the following figures, which give the mean of analyses by Konig 
of four samples of coffee before and after roasting: 



Water 

Caffeine 

Fat 

Sugar 

Cellulose 

Nitrogenous substances 

Other non-nitrogenous matter 
Ash 



Raw Coflee. 


Roasted Coflee 


11.23 


I-15 


1. 21 


1.24 


12.27 


14.48 


8-55 


0.66 


18.17 


10. 8g 


12.07 


13.98 


32-58 


45-09 


3-92 


4-75 



COMPOSITION OF THE ASH OF COFFEE.* 



Constituents. 

Sand 

Silica (SiOj) 

Ferric oxide (Fe20J. . . 

Lime (CaO) 

Magnesia (MgO) 

Potash (K„0) 

Soda (NaoO) 

Phosphoric acid (P2O5). 
Sulphuric acid (SO3). . . 
Chlorine (CI) 



Mocha. 



Maracaibo. 



Java. 



Riu. 



1-44 
0.88 
0.89 
7.18 
10.68 

59-84 

0.48 

12.93 

4-43 
1.25 



0.72 

0.88 

0.89 

5.06 

11.30 

61.82 

0.44 

13.20 

5-10 

0-59 



0.74 
0.91 
1. 16 
4-84 
11-35 
62.08 



14.09 
4.10 
0-73 



I 00 . 00 



1.34 
0.69 

1-77 

4.94 

10.60 

63.60 

0.17 

11-53 
4.88 
0.48 



The following are analyses of common varieties of roasted coffee, 
also of coffee substitutes and adulterated coffee made by Lythgoe:t 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 904. 

t An. Rep. Mass. State Board of Heahh, 1904, p. 3r!o. U. S. Dept. of Agric, Bur. of 
Chem., Bui. 90, pp. 43-45- 



394 



FOOD INSPECTION AND ANALYSIS. 



COMPOSITION OF ROASTED COFFEE. 

















Alka 


inity 


























(cc. 


M/io 




















< 






Add) of 




A 


J2 


c 
.2 

22, 






E« 


.c 


S 


Variety. 




6 
'3 

'o 


< 


1 


M 




_c 




2^ 
CM a 

Oc/3 

< 


< 

E 
2 



d 

"0 
w 




Ji 

1 
c 


W 

a, 




•3 




^A 


1 .40 


4.16 


3-46 


0.00 


0.023 


2.97 


71.4 


0.319 


0.346 


14-58 


1-4754 


2.26 


Santos 


E 


1.87 


4 


31 


3.62 


.00 


.023 


3-3b 


75-7 


.286 


-295 


13-84 


1-4754 


2.26 




,C 


I-3I 


3 


80 


3.00 


.00 


.019 


3-35 


85.6 


-273 


-295 


13.86 


1.4750 


2-39 


Porto 


A 


1.29 


4 


05 


3-30 


.00 


.016 


3-53 


87.2 


-305 


-337 


13.00 


1-4752 


2.28 


Rico 


B 


1.26 


4 


Ob 


3-27 


.00 


.020 


3-72 


92.6 


.226 


-351 


13-34 


1.4750 


2.26 




C 


1.48 


4 


12 


3-32 


.00 


.016 


3.66 


88.8 


•333 


-328 


14.12 


1.4760 


2-33 




A 


1.76 


4 


06 


3-40 


.00 


.020 


4.16 


102.3 


.213 


.166 


13-38 


1.4758 


2.14 


Rio 


a 


2.34 


3 


Qi 


3-24 


.00 


.021 


3-17 


81.2 


.356 


.227 


13-71 


1.4753 


2.18 


■i 


c 


2.10 


3 


74 


3.06 


.00 


.023 


3-22 


86.6 


.363 


-236 


13-53 


1.4756 


2.26 




A 


2.05 


4 


05 


3-25 


.00 


.016 


3-94 


97-4 


.282 


-351 


14.84 


*i.4737 


2.28 


Mocha 


B 


2-95 


3 


H5 


3-07 


.00 


.021 


3.26 


84-7 


■333 


-364 


14.47 


*i.4743 


2.00 




[c 


2.40 


3 


80 


3.00 


.00 


.012 


3-54 


93-3 


-337 


-545 


15.18 


*i.4740 


2.02 




A 


3-34 


4 


oq 


3-27 


.00 


.016 


3.88 


95-0 


-^58 


.421 


12.61 


1.4752 


2.48 


Java 


B 


3-35 


4 


3« 


3-56 


.00 


.019 


3-54 


80.8 


.194 


.3S8 


12.28 


1.4758 


2.35 




c 


3-44 


3 


q6 


3.10 


.00 


.oil 


2-95 


74.5 


-235 


-3H3 


13-54 


1-4752 


2.56 


Highest- 


.. 


3-44 


4 


3« 


3.62 


.00 


.023 


4.16 


102.3 


.424 


- 545 


15.18 


1.4760 


2.56 


Lowest. . 




1.26 


3 


74 


. 3-00 


.00 


.011 


2^95 


71.4 


.194 


.166 


12.28 


1-4750 


2.00 


Average . 




2.16 


4 


03 


3.26 


.00 


.018 


3-55 


87.1 


.285 


■329 


13-75 


1-4754 


2.27 





















Ten Per Cent Extract. 








4.1 

u 


■«-> 




6 


















>^ 


1 












X 




a 








0) N 








Variety. 




u 


2 

w 
"0 


M 
M 

M 


5 

Xi 


a 




> 

in 

« M 


E c 


•0-2 










•d 





3 

•0 


^ 


•d 




S^ 


c ca u 


££°o 


3 


J3 



















D. 


s 















< 


O^H 


w 








M 






w 


< 




'A 


20.80 


16.8^ 


0.52 


2.28 


13-41 


1-25 


I. 0107 


26.7 


1.33770 


2.64 


0.40 


Santos \ 


a 


22.72 


17. II 


.68 


I. 00 


II .02 


I. 10 


I. 0108 


26.9 


1.33777 


2.66 


.39 




c 


21.70 


17. So 


.75 


2.32 


14-71 


1.20 


I.OIOI 


26.0 


1.33743 


2.46 


.30 


Porto 
Rico 1 


A 


22.48 


15-70 


.50 


2.17 


13. II 


1-38 


I. 0107 


26.6 


1.33766 


2.60 


.37 


^ 


21.76 


16.36 


-63 


1-58 


12.93 


I. 21 


I. 0104 


26.3 


1-33754 


2.50 


-3t> 




[c 


24.44 


16.91 


-54 


2.62 


12.50 


1.32 


I.OII3 


27.6 


1.33804 


2-77 


.30 




A 


22.66 


17.00 


.68 


2.82 


14.08 


I. II 


I. 0103 


25-5 


1-33724 


2.48 


.40 


Rio 


i^ 


22.61 


17-34 


.78 


1-47 


13.10 


I. 10 


I.OIOI 


25-8 


1.33735 


2.46 


-36 




c 


22.75 


17-37 


.61 


2.62 


II. 91 


I. 17 


I.OIOI 


26.0 


1.33743 


2.46 


.30 




A 


24.00 


18.01 


1.78 


2.30 


11.22 


I. 16 


I. 0106 


26.4 


1.33758 


2.65 


.40 


Mocha ■ 


i^ 


20.27 


17.96 


.94 


1.8s 


12.34 


I. 10 


I.OIOI 


26.3 


1.33754 


2.47 


.36 




c 


24.18 


19-55 


1.42 


2.90 


13.20 


I. 18 


I.OIII 


27-3 


1.33793 


2.72 


.40 




A 


23.85 


15-95 


.32 


2.95 


13.43 


1-34 


I.OIIO 


29.6 


1.33777 


2.63 


.39 


Java \ 


ii 


22.19 


15-45 


.42 


2.32 


13-77 


1.30 


I. 0107 


26. e; 


1.33762 


2.58 


.38 




c 


23.20 


16.21 


.66 


3-34 


14-75 


1.27 


I. 0108 


26.6 


1.33766 


2.62 


.38 


Highest. . 




24.44 


19-55 


1.78 


3.34 


14-75 


1.34 


I.OII3 


27.6 


1.33804 


2.77 


.40 


Lowest. . 




20.27 


16.45 


.32 


1. 00 


11.02 


1. 10 


I.OIOI 


26.0 


1-33743 


2.46 


•30 


Average . 




22.63 


17-03 


-75 


2.30 


13-03 


I. 20 


I. 0105 


26.6 


1.33766 


2.72 


-37 



* Omitted from average. 



TEA, COFFEE, AND COCOA. 



395 



COMPOSITION OF COFFEE SUBSTITUTES AND OF ADULTERATED COFFEE. 





6 
o 


4 
< 


J3 
< 

_2 
•J} 

Id 


C 



G 




Alkalinity 
(cc. N/io 
Acid) of 


d 

3 
3 


c5 


a, 


C 

.0 

2 '^ 
^! 
-22 

c 




Variety. 


M 
< 


< 

B 
ca 




2 

•3 


Roasted wheat. 
Roasted chicory 
Coffee and 

chicory 

Coffee, chicory 

and pea hulls 


5.60 

5-55 

5.08 
3-64 


5-71 
4-37 

3-96 
4.97 


2.82 
2.27 

3-14 
4-05 


0.00 
.81 

.06 
-24 


0.080 

.026 

*.284 


0.34 
-95 

3-05 
2.60 


6.0 

21.8 

77.0 
65.6 


0.64Q 
.277 

.286 
.472 


I .460 
-314 

-323 
.740 


2.40 
.88 

8.32 
9-56 


1-4745 


1.84 

1. 10 

1.89 
2.17 





1 
w 

u 

u 



2 

X 

w 

■3 


< 


!3 

G 
'3 
3 

•a 

0) 


s 

p 


u 

0) 

3 

•V 


c 
'S 




Ten Per Cent Extract. 


Variety. 




1 

C JJ DO 

.2 E c 
i) u a 


^1 
-3-2 

(U g 

c 


■a 
1 




Roasted wheat 


25-88 
72.92 

31-79 
25.00 


10.72 
34-39 

21.66 
14-25 


4.10 
19-34 

5.06 
3.00 


28.58 
2.10 

2.21 

3-78 


6.23 
5-91 

14-31 
17.87 


0.00 
.00 

■95 
1. 00 












Roasted chicory 
Coffee and 

chicory 

Coffee, chicory 

and pea hulls 


1.0307 
I. 0142 


45-0 
30-5 


1-34463 
I -33915 


7-44 
3.62 


0.26 
.29 



* Admixture of salt. 



METHODS OF ANALYSIS. 

Preparation of the Sample. — Grind so as to pass a sieve with holes 
0.5 mm. in diameter. 

Determination of Moisture, Ether Extract, Fiber, Protein, and Ash 
(including total, water-soluble, water-insoluble, acid-insoluble and alka- 
linity) is carried out as in the case of tea pp. 381 and 382). Starch, Re- 
ducing Matters by Acid Conversion, Sucrose, and Reducmg Sugars may 
be estimated as in cereals, Acidity as described on page 1035. 

Determination of Ten per Cent Extract. (See page 403). 

Determination of Caffetannic Acid. — Krug Method* — Although so- 
called caffetannic acid has been shown to be a mixture of chlorogenic 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 908. 



396 



FOOD INSPECTION AND ANALYSIS. 



and coffalic acids, the method of determining this mixed substance is still 
retained. 

Two grams of the coffee are digested for 36 hours with 10 cc. of water, 
after which 25 cc. of 90% alcohol are added, and the digestion continued 
for 24 hours more. The Hquid is then filtered, and the residue washed 
with 90% alcohol on the filter. 

The filtrate, which contains tannin, caffeine, fat, etc., is heated to 
boiling and a boiling concentrated solution of acetate of lead is added, 
which precipitates out a caffetannate of lead, Pb3(Ci5H 1508)2, containing 
49% of lead. When this has become flocculent, it is separated by filtra- 
tion, and washed on the filter with 90% alcohol, till the washings show 



Mk 






II. 

Fig. 75. — Coffee. I. cross-section of berry, natural size. Pk outer pericarp; Mk endocarp; 
£)fe spermoderm; 5(1 hard endosperm; 5/* soft endosperm. II. Longitudinal section of 
berry, natural size; Dis bordered disc; Se remains of sepals; Em embryo. III. Embryo 
enlarged; co/ cotyledon; rad radicle. (Tschirch and Oesterle.) 

no lead with ammonium sulphide, and afterwards with ether, till free 
from fat. It is dried at ioo° and weighed. 

The weight of caffetannic acid is obtained by multiplying the weight 
of the precipitate by 652, and dividing by 1263 63. 

Woodman and Taylor's Modification.^ — To 2 grams of finely ground 
coffee (passing 0.5 mm. sieve), add 10 cc. of water, and shake for an 
hour in a mechanical shaking device. Add 25 cc. of 90% alcohol and 
shake again for half an hour. Filter and wash with 90% alcohol. Bring 
the united filtrate and washings, about 50 cc, to boiling, and add 6 cc. 
of saturated lead acetate solution. Separate the precipitated lead caffe- 
tannate by means of a centrifuge, decanting the supernatant liquid 
through a tared filter. Repeat the centrifugal treatment twice with 90% 
alcohol, decanting each time through the filter. Transfer the precipitate 
to the filter, and wash free from lead. Wash with ether, dry at 100°, and 



U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 82. 



TEA, COFFEE, AND COCOA. 397 

weigh. The weight of the precipitate multipUed by 0.516 gives the weight 
of caffetannic acid. 

Caffeine. — Gorter Method* — Moisten 11 grams of the finely powdered 
coffee with 3 cc. of water, allow to stand for half an hour, and extract 
for 3 hours in a Soxhlet or Johnson extractor with chloroform. Evaporate 
the extract, treat the residue of fat and caffeine with hot water, filter 
through a cotton plug, and wash with hot water. Make up the filtrate 
and washings to 55 cc, pipette off 50 cc, and extract four times in a 
separatory funnel with chloroform. Evaporate this chloroform extract 
in a tared flask, dry the caffeine at 100° C, and weigh. 

Calculate the caffeine also from the nitrogen content. 

Lendrich and Notthohm Method.^ — This method is recommended by 
Murray % for the examination of decaffeinated coffee and other prepara- 
tions containing small amounts of caffeine, as it yields lower and more 
accurate results than the Gorter method. 

Moisten 20 grams of the sample, ground to pass a i-mm. mesh, with 
10 cc of water, stir occasionally for 1-2 hours, and extract 3 hours with 
carbon tetra-chloride in an extraction thimble. To the extract add 
I gram of paraffin, distil off the solvent, and exhaust the residue with 
I portion of 50 cc. and 3 of 25 cc. of boiling water. Cool the combined 
aqueous extract, filter through a moistened paper, wash with hot v/ater, 
add 10-30 cc. of 1% potassium permanganate solution, and allow to 
stand 15 minutes. Precipitate the excess of manganese as peroxide by 
means of a little 3% hydrogen peroxide solution containing 1% oi glacial 
acetic acid added drop by drop, heat 15 minutes on a boiling water- bath, 
filter, wash with boiling water, evaporate the filtrate to dryness, and dry 
further in a boiling water-oven. Exhaust the dry residue with warm 
chloroform, decanting into a tared dish, remove the chloroform by evapora- 
tion, dry the residue 30 minutes in a boiling water-oven, and weigh the caf- 
feine. Murray recommends that nitrogen be determined in the weighed 
residue as in the Gorter method. 

ADULTERATION OF COFFEE. 

According to the U. S. Standard roasted coffee is coffee which, by the 
action of heat, has become brown and developed its characteristic aroma, 
and contains not less than 10% of fat, and not less than .3% of ash. 

* Annalen, 1908, 358, p. 327. 

t Zeits. Unters. Nahr. Genussm., 17, 1909, p. 241. 

X Jour. Ind. Eng. Chem., 5, 1913, p. 668. 



398 FOOD INSPECTION AND ANALYSIS. 

Imitation Coffee. — Formerly, artificial coffee-beans containing no 
coffee whatever, but cleverly molded to imitate the original, were occa- 
sionally to be found, mixed with genuine, whole coffee. 

" Coffee pellets " are occasionally sold in bulk to dealers as an adulter- 
ant of whole coffee. These do not closely resemble the real berries in 
appearance, but are approximately of the same size, and are not apparent 
to the purchaser when the whole coffee is ground at the time of purchase. 
A sample of these " pellets " examined recently was found to consist of 
roasted wheat mash, colored with red ocher. 

Coloring Coffee Beans. — The practice of treating raw coffee beans 
in a manner somewhat analogous to the facing of tea leaves has been 
sometimes practiced, with a view to giving to cheaper or inferior grades 
the appearance of high-priced coffee. For this purpose various pigments 
have been employed, such as yellow ocher, chrome yellow, burnt umber, 
Venetian red, Scheele's green, iron oxide, turmeric, indigo, Prussian 
blue, etc., the coffee beans being first moistened with water containing 
a little gum, and shaken with the pigment. As a rule such pigments, 
especially when inorganic, are best sought for either in the ash, or in the 
sediment obtained by shaking the coffee beans in cold water, using the 
ordinary qualitative chemical methods. Organic coloring matters can 
be best extracted with alcohol. Prussian blue and indigo are tested for 
as in the case of tea leaves (p. 387). 

Glazing. — This is a more recent form of treatment of the whole bean, 
which consists in coating the beans by dipping in egg or sugar, or a mix- 
ture of the two, sometimes using various gums. Such glazing is alleged 
to improve the keeping qualities of the coffee, as well as to aid in clarify- 
ing the infusion, and if this is the sole purpose, the practice cannot be 
condemned as a form of adulteration. If, however, it is done to give 
inferior varieties of coffee a better appearance, in order to deceive the 
consumer, it clearly constitutes adulteration within the meaning of the 
law. 

Adulterants of Ground Coffee. — Of the adulterants used in ground 
coffee the following have been found in Massachusetts: Roasted peas, 
beans, wheat, rye, oats, chicory, brown bread, pilot bread, charcoal, 
red slate, bark, and dried pellets, the latter consisting of ground peas, 
pea hulls, and cereals, held together with molasses. 

Methods of Detecting Adulterants. — These methods are, as a rule, 
physical rather than chemical. A rough test of the genuineness of ground 
coffee consists in shaking some of the sample in cold water. Pure coffee. 



TEA, COFFEE, AND COCOA. 399 

under these conditions, usually floats on the surface, while the ordinary 
adulterants, such as cereals, chicory, mineral ingredients, etc., sink, 
th? grains of chicory coloring the water a brownish-red as they subside. 

Macfarlane recommends the use of a saturated solution of common 
salt, in which a portion of the suspected sample, divided in small grains, 
is shaken in a test-tube. If the liquid is colored pale amber, while all 
or nearly all the material floats, the coffee is pure. Any considerable 
sediment at the bottom of the tube, accompanied by a dark-yellow to 
brown color imparted to the liquid, indicates adulteration by roasted 
cereals, or chicory, or both. 

A careful examination of the coarsely crushed grains of a ground 
sample with the naked eye will often serve to detect, and in some cases 
identify, certain adulterants, such as chicory and ground peas or beans. 
A magnifying-glass will aid in such an examination, and the observer 
can often separate the various ingredients of a coffee mixture, first spread- 
ing a small portion of the sample on a sheet of white paper. The chicory 
grains are apparent from their dark and somewhat gummy appearance, 
and can usually be recognized by crushing them between the teeth. Their 
soft consistency and sweetish bitter taste are very distinctive. The dull 
outer surface of the crushed coffee grains is in marked contrast to the 
polished appearance of the surface of the broken peas or beans, often to 
be found as adulterants, while fragments of broken cereal grains are 
readily distinguished from coffee with a low-power magnifier, though 
perhaps not easily identified by the eye alone. 

Determination of Added Starch. — Starch is determined in the finely 
powdered sample as directed on page 292. 

Microscopical Examination of Coffee. — By far the best means of 
detecting adulteration is furnished by the microscope. The individual 
grains of coarsely ground coffee and adulterants, separated by the cold 
water test or by picking over the mixture, are identified by microscopic 
examination either after sectioning with a razor or crushing to a powder. 
In addition, examination is made of a. small portion of the sample pulver- 
ized in a mortar to a degree fine enough to allow the cover-glass to lie 
flat on the wetted powder, yet not so fine that it ceases to feel granular 
when rubbed between the fingers. The writer finds it sufficient to 
examine this powder in water without further treatment, although 
Schimper recommends maceration for twenty-four hours with ammonia, 
in order to render the tissues more transparent, using this reagent also 
as a mountant. 



400 FOOD INSPECTION AND ANALYSIS. 

In general the interior of the coffee tissue or endosperm consists of 
polygonal cells with highly characteristic, knotty, thickened walls, which 
are best seen in razor sections, Fig. 76, 2. These cells contain brilliant, 
colorless, spherical oil drops, and also proteins. 

The seed coat is also very characteristic, showing in the powder as 
occasional delicate silver-like patches, with peculiar, spindle-shaped, 
thick-sided cells, some of which are loosened from the tissue. 

Plates XIV and XV illustrate photomicrographs of pure and adulter- 
ated coffee. Fig. 174 shows genuine coffee, with its loose mesh of irreg- 
ularly polygonal cells, thick-walled, and inclosing oil drops with amor- 
phous material. It is not to be expected that every pulverized sample of 
genuine coffee, mounted as above, will show in every microscopic field the 
even, continuous structure that Fig. 174 illustrates, but careful examination 
will show in nearly every field fragments, and more or less disjointed por- 
tions of the polygonal cells, grouped in the form so characteristic of coffee. 
See Fig. 176. 

Chicory under the Microscope. — Fig. 77, after Moeller, shows struc- 
tural features of chicory. The most striking elements are the fine, thick- 
walled, long-celled, parenchyma of the. bark rp and hp with its delicate 
tracery, and the vcssils or ducts g of the wood fibers. These ducts are 
tubular, resembling jointed cyhnders, often with overlapping joints. 
Less distinct, but very characteristic of certain roots of the composite 
family, are the narrower branching milk ducts sch which do not exist 
in beets and turnips, which are sometimes substituted for chicory. 

Fig. 178, PL XV, is a photomicrograph of an adulterated sample of 
coffee, showing in this particular field chicory alone. It is a mass of con- 
fused cellular tissue, traversed by two broad bands of the vessels, with 
their striking, transverse, dotted markings. 

Fig. 177, PL XV, shows a sample of coffee adulterated with roasted 
peas and pea hulls. No genuine coffee appears in this field. The chief 
masses in the center are characteristic aggregations of the round starch 
granules of the roasted pea. The rectangular billets, like bunches of 
matches, are from the outer or palisade layer of the pea. 

Fig. 164, PL XI, and Fig. 154, PL IX, show the close resemblance 
between the starches of the pea and bean, both of which are commonly 
used in coffee. 

The palisade structures of the hulls of these legumes also bear a close 
resemblance, but the cells of the next layer in the pea are hour-glass 



TEA, COFFEE, AND COCOA. 



401 




Fig. 76.— -Powdered Coffee under the Microscope. X125. (After Moeller.) i, seed 
coat (surface). 2, endosperm parenchyma. 




qic 'T 




WWim 

Fig. 77. — Chicory Root in Tangential and Radial Sections. X160, g, reticulated ducts 
with perforations qu; hp, wood parenchyma; /, wood fibers; rp, bark parenchyma; 
sch, milk ducts; bp, bast parenchyma; nt, medullary rays. (After Moeller.) 



402 



FOOD INSPECTION AND ANALYSIS. 



shaped, while in the bean they are not remarkable for their shape, but for 
the single crystal of calcium oxalate contained in each. 

The effect of roasting on starches used as adulterants of coffee is to 
twist and distort the granules, in some cases destroying largely the even 
structure of the raw starch. Starch granules of wheat, barley, and rye, 
for example, are almost perfect circular disks in the case of the raw starch, 
while in roasted products, such as pilot biscuit and stale bread, the 
granules are twisted and distorted, sometimes almost forming the letter 
" S." 

Use of Chicory in Coffee. — Chicory is a perennial herb {C'.c'iorium 
intyhus) of the same family {Composite) as the dandelion. The roasted 
and pulverized chicory root is so much used in ground coffee to impart 
a peculiar flavor thereto, that by many it is considered as not strictly 
an adulterant. The taste imparted to coffee by a small admixture of 
pure chicoiy is to some desirable, but if its unrestricted use is sanctioned 
in this manner, the door would soon be opened to a more unlimited form 
of adulteration, wherein the chicor}^ might predominate. It is, therefore, 
best to regard chicory as an adidterant, and to require the package con- 
taining a mixture of coffee and chicory, if sold legally, to have plainly 
printed thereon the percentage of chicory in the mixture. 

Chicory, when roasted, consists of gum, partly caramelized sugar,, 
and insoluble vegetable tissue. Common adulterants of chicory are 
dried beets and other roots, also cereal matter. 

Villiers and Collin * give the following analyses of two samples of 
chicory. See also analysis of roasted chicory on page 395. 



Soluble in water: 



Insoluble in water: 



Water (loss at ioo° to 103°) 

Weight of total matter soluble in water. 

Reducing sugar 

Dextrin, gum, inulin 

Album inoids 

Mineral matter 

. Coloring matter 

' Albuminoids 

Weight of the total insoluble matter. . .. 
•| Mineral matter 

Fat 

[ Cellulose 



In Large 
Granules. 



16.28 
57-96 

26. 12 
9-63 
3-23 
2.58 

16.40 

3-15 
25.76 

4-58 

5-71 

12.32 



In Powder. 



16.96 

56.90 

23-79 

9-31 

3.66 

2-55 
17-59 

2.98 
26.14 

5-87 

3-92 
13-37 



* Falsifications et Alterations des Substances Alimentaires, p. 234. 



TEA, COFFEE, AND COCOA. 403 

Detection and Estimation of Chicory. — Various chemical tests for 
detection of chicory in coffee infusions have been suggested, depending on 
color reactions,* but these are, as a rule, unreliable. By far the best 
means for detecting chicory in cofifee is furnished by the microscope. 

In mixtures containing coffee and chicory only, the approximate amount 
of the latter can be obtained by McGill's method,t as follows: Weigh 
a quantity of the pulverized sample, corresponding to lo grams of the 
dry substance, into a counterbalanced flask, and add water till the weight 
of the contents is no grams. Bring to boiling in ten to fifteen minutes 
and continue the boiling for an hour under a reflux condenser. Cool 
for fifteen minutes, pass through a dry filter, and determine the specific 
gravity at 15°. McGill found the average specific gra\ity of a 10% 
decoction as above carried out to be, in the case of pure coffee 1.00986, 
and in the case of chicory 1.0282 1, the difference being 0.01835. The 
specific gravity of the 10% decoction of the suspected sample at 15° being 
d, the per cent of chicory, c, can be calculated roughly by the formula: 

(1.02821 —d)ioo 

c= 100 — — . 

0.01835 

As a means of detecting chicory in the beverage La Wall J determines 
the amount of extract and the percentage of reducing sugars in the extract. 
The latter in genuine coffee ranged from 1.92 to 2.64%, whereas in two 
samples of chicory it was over 25%; consequently addition of 5 parts 
of chicory to 100 parts of the coffee showing the highest ratio, increased 
the percentage of reducing sugar in the extract to 4.6. 

Date Stones, roasted and ground, have been used to some extent as a 
coffee adulterant. Fig. 78 shows the structural features of date stones 
under the microscope. End represents a fragment of endocarp with its 
elongated, thick-walled cells, peculiarly arranged as shown, adjacent cells 
often lying with axes at right angles to each other. The more evenly 
formed episperm cells, e, are thin-walled and of a brown color. The 
albumen, a, is made up of very thick-walled, somewhat regularly arranged 
cells, indented from within with deep channels. Date stones are readily 
distinguished from coffee by these features. 

* See Allen's Commercial Org. Analysis, 4 Ed., Vol. VI, pp. 671, 672. 
t Trans. Royal Soc. of Canada, 1887. 
t Am. J. Pharm., 1913, p. 535. 



404 



FOOD INSPECTION AND ANALYSIS. 



Hygienic Coffee. — Various processes have been devised for removing 
the caffeine from coffee. One of these, patented in Germany, has recently 
come into extensive use, as the flavor of the beverage is not greatly injured 
by the treatment. In follow^ing out this process the whole beans are first 
exhausted vi^ith water in a vacuum, and the infusion extracted with a 
suitable solvent for caffeine. The exhausted beans are then impregnated 
with the decaffeinated infusion and dried in a vacuum. This treatment, 
as shown by the investigations of Lendrich and Murdfield,* does not 




Fig. 78. — Powdered Date Stones under the Microscope, end, endocarp; e, episperm; 
a, albumen in cross-section; a' , albumen in longitudinal section. (After Villiers and 
Collins.) 

completely remove all the caffeine, the quantity remaining being from 
0.14 to. 0.26%, or about one-sixth of that in the untreated coffee. Further 
effects of the treatment are a decrease in the water extract and an increase 
in the fat. The following are the average of analyses, made by these 
authors, of caffeine-free and untreated coffee : 





0) 

■(3 

c 
< 








Analysis 


of the Dry Substance. 








3 


of Ash 
I HCl 

grams 
e). 


i 


if 
3 u 

•5^ 










u 

E 

3 


6 

u 

3 
S 


< 





Alkalinity 
(cc. N/ 
per 100 
of Coflfe 


w 




Co 




.S2 






% 


% 


% 




% 


% 


% 


% 


"Caffeine-free Coffee". .. 


14 


2.13 


4-23 


3.22 


47-72 


21.30 


17-13 


0. 22 


11.83 


Untreated coffee 


9 


1.46 


4.71 


3-77 


56-43 


26.17 


15-73 


I. 19 


11-75 



Zeits. Unters. Nahr. Genussm., 15, 1908, p. 705. 



TEA, COFFEE, AND COCOA. 



405 



Several brands of coffee advertised to be free from tannin and in 
some cases also from caffeine, have been placed on the market in the 
United States. Some of these consist merely of ground coffee from 
which the chaff (which is represented to contain not only the tannin but 
also most of the caffeine) has been removed by mechanical means. The 
absurdity of the claims of the manufacturers is shown by the following 
analyses made in New Hampshire by C. D. Howard.* 



Water. 


Ash. 


Fat. 


Fiber. 


Caffeine. 


2.70 


4.10 


13.18 


18.46 


1. 17 


2.70 


4-05 


14.12 


15-70 


^■33 


2.26 


3-6i 


12.55 


22.70 


0.87 


3-13 


4-13 


14.10 


15-50 


1.29 


2.60 


5.65 


9-30 


26.50 


0.40 



Caflfe- 
tannic 
Acid. 



Tanninless coffee No. i. . . 
Tanninless coffee No. 2. . . 
Tanninless coffee No. 3. . . 

Java and Mocha 

Coffee chaff 



10.76 
11.04 

7.61 
II. 17 

5-98 



The following analyses made at the Connecticut Station by E. 
Shanley,t corroborate those of Howard: 





Caffeine in the 
Coffee. 


Caffetannic 

Acid in the 

Coffee. 


Caffetannic 

Acid in the 

Chaff. 


Per Cent of 

Chaff in the 

Coffee. 


Tanninless coffee A 


1. 14 

1. 11 

1. 12 

1. 13 

1.26 

I-I3 


9.89 
9-45 
9-96 
9-51 
9.96 

9-47 


5-46 

7-55 
6.79 




Tanninless coffee B 




Tanninless coffee C 




Java coffee 


I 80 


Mocha coffee 


2-38 

1-77 


Rio coffee 





The Asa process consists in treating the raw coffee with water vapor 
under a pressure of 4.5 atmospheres and distilling in vacuo, thus removing, 
it is claimed, volatile toxic substances. 

Vacuum packed coffee has been extensively advertised as being free 
from the objectionable qualities of ordinary coffee. Gould's experiments J 
indicate that the composition of the vacuum-packed coffee is not quite 
the same as that of ordinary coffee, nor is the gas given off the same, but 
whether these changes render the coffee more wholesome appears uncertain. 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 105, p. 41. 

t Ann. Rep. Conn. Exp. Sta., 1907, p. 141. 

X Eighth Int. Cong. App. Chem., 26, 191 2, p. 389. 



406 FOOD INSPECTION AND ANALYSIS. 

Coffee Substitutes. — A large number of preparations sold as " cofifee 
substitutes " or " cereal co£fee " are now on the market in the United 
States, most of which are composed, as alleged on the labels, of cereals, 
ground peas, etc. Some contain roasted wheat, malt or some other 
cereal alone, others are mixtures of cereals or cereal products and peas, 
and a few contain chicory. Some of these preparations have labels 
calling attention to the evil effects of coffee, and one of the latter class, 
extensively advertised, and purporting to contain nothing but the entire 
wheat kernel roasted and ground, was found to contain peas, and aboui 
30% of that " most harmful ingredient " coffee itself. Various substitutes 
are also made from dried fruits such as figs, prunes and bananas. 

In addition to the materials named the following have been used in 
Europe: beans, lupine seeds, cassia seeds, astralagus seeds, Parkia seeds, 
chick peas, soy beans, dried pears, carob bean pods, date stones, ivory 
nuts, acorns, grape seeds, fruit of the wax palm, cola nuts, false flaxseed, 
dandelion roots, beets, turnips and carrots.* 

As in the case of coffee the analyst must depend chiefly on the micro- 
scope in identifying the constituents of coffee substitutes. Coffee itself 
should properly be considered in the light of an adulterant. 



COCOA AND COCOA PRODUCTS. 

Nature of the Cocoa Beans. — The various chocolate and cocoa prep- 
arations are made from the bean of the tree Theohroma cacao, of the 
family of ByitneriacecB. This tree averages 13 feet in height, and its main 
trunk is from 5 to 8 inches in diameter. It is a native of the American 
tropics, where it is still most successfully grown for supplying the world's 
market. 

The cocoa beans of commerce are derived chiefly from Ariba, Bahia, 
Caracas, Cayenne, Ceylon, Guatemala, Haiti, Java, Machala, Mara- 
caibo, St. Domingo, Surinam, and Trinidad. Besides these, the Sey- 
chelles and Martinique furnish a small amount. 

The plant seeds, or beans, grow in pods, varying in length from 23 to 
30 cm., and are from 10 to 15 cm. in diameter. The beans, which are 
about the size of almonds, are closely packed together in the pod. Their 
color when fresh is white, but they turn brown on drying. 

* Winton's Microscopy of Foods, p. 435. 



TEA, COFFEE, AND COCOA. 407 

The gathered pods are first cut open, and the seeds removed to undergo 
the process of " sweating " or fermenting, which is carried out either 
in boxes or in holes made in the ground. This process requires great 
care and attention, as upon it depends largely the flavor of the seed. 
The sweating operation usually takes two days, after which the seeds 
are dried in the sun till they assume their characteristic warm red color, 
and in this form are shipped into our markets. 

Manufacture of Chocolate and Cocoa. — For the production of choc- 
olate and cocoa the beans are cleaned and carefully roasted, during which 
process the flavor is more carefully developed, and the thin, paper-like 
shell which surrounds the seed is loosened, and is very readily removed. 
The roasted seeds are crushed, and the shells, which are separated by 
winnowing, form a low-priced product, from which an infusion may be 
made, having a taste and flavor much resembling chocolate. 

The crushed fragments of the kernel or seed proper are called cocoa 
nibs, and for the preparation of chocolate they are finely ground into 
a paste and run into molds, either directly, or after being mixed with 
sugar and vanilla extract or spices, according to whether plain or sweet 
chocolate is the end product. 

For making cocoa, however, a portion of the oil or fat known as the 
cocoa butter is first removed, by subjecting the ground seed fragments 
to hydraulic pressure, usually between heated plates, after which the 
pressed mass is reduced to a very fine powder, either directly, or by treat- 
ment with anmionia or alkalies, to render the product more " soluble." It 
is held that the large amount of fat contained in the cocoa seeds (vary- 
ing from 40 to 54%) is difficult of digestion to many, such as invalids 
and children, and hence the desirability of removing part of the fat. 

Composition of Cocoa Products. — The chief constituents of the raw 
cocoa nib are fat, starch, pentosans, proteins, theobromine, caffeine, tan- 
nin, and mineral matter. Minor constituents are oxalic acid (combined), 
acetic and tartaric acids. During roasting there is reason to believe a 
volatile substance is developed much in the nature of an essential oil, 
which gives to the product its peculiar flavor, and is somewhat analogous 
to the caffeol of coffee. 

Tannin, the astringent principle of cocoa, exists as such in the raw 
bean, but rapidly becomes oxidized to form cocoa red, to which the color 
of cocoa is due. 

Weigmann gives the following results of analyses of cocoa niljs and 
shells: 



408 



FOOD INSPECTION AND ANALYSIS. 



COMPOSITION OF COCOA NIBS. 



Commercial Vajieties. 









U 



Caracas 7 

Trinidad 7 

Surinam ! 7 

Port au Prince 7 

Machata 8 

Puerto Cabello 8 

Ariba 8 



14-13 
14.06 
13.69 
14.56 
14.06 
13-50 
15-37 



1-31 
1.66 



1-51 



45-54 
44.62 

44-74 
46-35 
45-93 
46.61 

45-15 



1 9. -40 
25-30 
26.45 
5-97 
5-69 
22.9 

5-83 



15-53 
17-50 



16.96 



6.19 
4-55 
4-30 
5-19 
4-36 
4-43 
4.48 



4.91 
3-48 
3.16 

4-iS 
4.09 
4.28 
3 88 



2.06 
o.io 
0.13 
1.48 
0.22 
0.18 
0.14 



COMPOSITION OF COCOA SHELLS. 







p V 

















Commercial Varieties. 


1 




1 






(1) 

"3 




T) 


"3 c 






i3 :3 


(U 


■4J 






.c 


c 






S 


gc/. 


H 


fe 


gW 


6 


< 




u^ 


Caracas 


12.49 


13.18 

14.62 


0.58 
0.74 
0.78 

0.75 


2-38 


40.30 


16.33 


9.06 


6.26 


2.11 


Trinidad. 


14.64 


3-45 


44-89 


15-79 


6.19 


0.42 


2-34 


Surinam 


13-93 
14.89 


16.25 
16.18 


2-54 


42.47 


17.04 


6.63 


0.85 


2.60 


Puerto Cabello 


2.01 


43-32 


15-25 


8.08 


0.27 


2-59 







On page 409 are the summarized results of the analyses of seventeen 

varieties of cocoa seeds and shells, made by Winton, Silverman, and Bailey.* 

According to Bell f the ash of cocoa nibs has the following composition: 

Per Cent. 

Sodium chloride o-57 

Soda 0.57 

Potash 27 . 64 

Magnesia 19.81 

Lime 4 . 53 

Alumina 0.08 

Ferric oxide 0.15 

Carbonic acid 2.92 

Sulphuric acid 4.53 

Phosphoric acid 39 - 20 



100.00 



* Ann. Rep. Conn. Agric. Exp. Sta., 1902, p. 270. 
t Analysis and Adulteration of Foods. 



TEA, COFFEE, AND COCOA. 



409 



Roasted Cocoa Nibs. 



Air-dry Material. 



Maxi- 
mum. 



Mini- 
mum. 



Mean. 



Water- and Fat-free 
Material. 



Maxi- 
mum. 



Mini- 
mum, 



Mean. 



Water , 

Total ash , 

Water-soluble ash 

Ash insoluble in acid 

Alkahnity of ash , 

Theobromine 

Caffeine 

Other nitrogenous substances 

Crude fiber , 

Crude starch (acid conversion) 

Pure starch (diastase conversion) 

Other nitrogen-free substances 

Fat 

Total nitrogen 

Constants of fat (ether extract) : 

Melting-point, degrees C 

Zeiss refractometer reading at 40° C 

Refractive index at 40° C 

Iodine number 

Per cent of nibs in whole bean 

" " "shells " " " 



3.18 

4-15 
1.86 
0.07 

3-35 
1.32 

0-73 
13.06 

3.20 
12.37 

8-99 
21.07 

52-25 

2.54 

35-0 
48.00 

[-4579 
37-89 
92.90 
13.88 



2.29 
2.61 

0-73 
0.00 

1-5° 
0.82 
o. 14 
II .00 
2.21 

9-30 

6.49 

17.69 

48.11 

2.20 

32-3 
46.00 

r-4565 

33-74 

86.12 

8.83 



2.72 
3-32 
1. 16 
0.02 

2-51 
1.04 
0.40 

12.12 
2.64 

II. 16 
8.07 

19-57 

50.12 

2.38 

33-3 
47-23 
1-4573 
34-97 
88.46 

11-54 



3-96 
o. 14 
7.12 
2.92 

1-55 
28.05 

6.56 
25.68 
18.61 
44.08 

5-41 



5-76 
1.60 



3-29 
1.66 
0.31 

23-37 
4.70 
19.80 
13.82 
38.78 

4-74 



7.04 
2.46 
0.05 

5-32 

2.21 

0.86 

25.69 

5-61 

23.66 

17.10 

41.49 

5-05 



Roasted Cocoa Shells. 



Air-dry Material. 



Maxi- 
mum. 



Mini- 
mum. 



Mean. 



Water- and Fat-free 
Material. 



Maxi- 
mum. 



Mini- 
mum. 



Mean. 



Water 

Total ash 

Water-soluble ash 

Ash insoluble in acid 

Alkalinity of ash 

Theobromine 

Caffeine 

Other nitrogenous substances 

Crude fiber 

Crude starch (acid conversion). . 
Pure starch (diastase conversion) 
Other nitrogen-free substances. . 

Fat.. 

Total nitrogen 



6-57 
20.72 

5-67 
II. 18 

5-92 

0.90 

0.28 

18.06 

19.21 

13.89 

5.16 

51.86 

5-23 

3-17 



3-71 

7.14 
2.02 
0.05 

5-02 

0.20 

0.04 

10.69 

12.93 

9.87 

3-36 

43-71 
1.66 

1-74 



4-87 
10.48 

3-67 
2-51 
5-52 
0.49 
0.16 

14-54 

16.63 

11.62 

4.14 

46.40 

2.77 

2.34 



21.97 

6. II 

11.86 

6-47 

0.97 

0.31 

19.40 

20.72 

15-42 

5-59 

55-84 

3-41 



5-63 
2.16 
0.05 

5-32 

0.22 

0.04 

11-34 

13-71 

10.47 

3-65 
47.04 

1.87 



11-33 
3-97 
2.70 

5-97 
0.52 
o. 17 

15-70 
18.01 

12.59 

4-47 

50.08 

2.54 



410 



FOOD INSPECTION AND ANALYSIS. 



Theobromine (C7H8N4O2), the chief alkaloid of cocoa, when pure, 
forms a white, crystalline powder, having a bitter taste. It is slightly 
soluble in water and alcohol, very slightly soluble in ether, insoluble 
in petroleum ether, but readily soluble in chloroform. It sublimes at 
290° to 295° C. It is a weak base, and much resembles caffeine. A small 
amount of caffeine has also been found in cocoa, but in most analyses 
is reckoned in with the theobromine. 

The Nitrogenous Substances of Cocoa, aside from the alkaloids, have 
been little studied. Stutzer has, however, separated them roughly as 
in the following analyses of four samples, of which A was manufactured 
without chemicals, B with potash, and C and D with ammonia : 



Total nitrogen 

Theobromine 

Ammonia 

Amido compounds 

Digestible albumin 

Indigestible nitrogenous substances 

Containing nitrogen 

Proportion of total nitrogen indigestible 



A. 


B. 


c. 


3.68 


3-30 


3-95 


1.92 


1-73 . 


1.98 


0.06 


0.03 


0.46 


1-43 


1-25 


0-31 


10.25 


7.68 


10.50 


7.18 


9.19 


7.68 


I-I5 


1-47 


1-23 


31.2 


44.5 


31.2 



3-57 
1.80 

0-33 
1-31 
7.81 
8.00 
1.28 
35-8 



Pentosans. — Several authors have called attention to the value of 
these substances as a means of detecting added shells in cocoa products. 

Liihrig and Segin * found in cocoa nibs from 2.51 to 4.58% of 
pentosans calculated to the dry, fat-free substance, and in the shells from 
7.59 to 11.23% calculated to the dry substance. 

Milk Chocolate, a product of comparatively recent introduction, 
consists of a mixture of chocolate, sugar, milk powder, and cocoa butter. 
It is especially prized by travelers and others who desire a concentrated, 
and at the same time palatable food. 

The following analyses by Dubois f show the composition of three 
of the leading brands on the market, and also illustrate the accuracy of 
Dubois' method of determining sucrose and lactose given on page 415. 

Various Compounds of chocolate or cocoa with other materials have 
been placed on the market. Zipperer | gives formulas or analyses of 
seventy-four such preparations, containing one or more of the following 
ingredients: oatmeal, barley meal, malt, malt extract, wheat flour, potato 



* Zeits. Unters. Nahr. Genussm., 12, 1906, p. 161. 

t Jour. Am. Chem. Soc, 29, 1907, p. 556. 

t The Manufacture of Chocolate and Cacao Preparations, 2d ed., 1902. 



TEA, COFFEE, AND COCOA. 



411 





Polarization. 


Su- 
crose, 

Per 
Cent. 


Lac- 
tose, 
Per 
Cent. 


Reich- 

ert- 
Meissl 

Num- 
ber of 
Fat. 


Approx. 
Per Cent 




Direct. 


After 
Inver- 
sion. 


Temp. 


At 86°. 


Fat in 
Total 
Fat. 


Commercial milk chocolate: 
A 


+ 21. OO 
+ 23.22 
+ 23.88 

+ 19.00 


— 2.00 

— 2.22 

— 2.20 

-1.50 


24 

23 
23 

20 


+ 1.36 
+ 1.50 
+ 1-36 

+ 1.40 


40.90 

45-73 
46.78 

35-99 
35-82 
39-84 
39.80 


8.24 
9.12 
8.24 

8.52 
8.82 
6.03 
5-88 


5-3 
5-5 
5-8 

4-83 
3-48 




B 


22.9 
24.2 


c 


Milk chocolate made in the 
laboratory: 
J-. / Found 


\ Calculated 




■p f Found 


+ 19.70 


— 2.20 


21 


+ 0.99 


14.5 


^ \ Calculated 















flour, rice, peas, peanuts, acorns, cola nuts, sago, arrowroot, Iceland 
moss, gum Arabic, salep, dried meat, meat extract, peptones, milk powder, 
plasmon (a preparation of casein), eggs, saccharin, vanilla, spices, and 
inorganic salts. Certain medicinal preparations also contain cocoa 
products. 

Cocoa Butter. — See Chapter XIII. 

METHODS OF ANALYSIS. 

Preparation of the Sample.— Cocoa is usually in a fine powder, and 
needs merely to be put through a sieve, to break up lumps, and mixed. 
Chocolate should be grated or shaved so as to permit mixing. It can- 
not be ground, as the heat of grinding reduces it to a paste. 

Determination of Moisture. — Dry 2 grams of the material to con- 
stant weight at 100° C. in a current of dry hydrogen. Somewhat lower 
results are obtained by drying in a dish in air. 

Determination of ksh..~Total, Water-soluble, and Acid-soluble. — Pro- 
ceed as described under tea (page 382), 

Alkalinity {Ewell Method^). — To the ash of 2 grams of the sample 
add 100 cc. of water, an excess of N/io sulphuric acid, and boil until 
carbon dioxide is removed. Titrate the excess of acid with N/io alkali, 
using phenolphthalein as indicator. Calculate the number of cubic 
centimeters of N/io acid required to neutralize the ash from i gram of 
the sample. 

This method was used by Winton, Silverman, and Bailey, in the 



U. S. Dept. of Agric, Div. of Chem., Bui. 13, 1892, p. 956. 



412 



FOOD INSPECTION AND ANALYSIS. 



analyses as summarized on page 409. It is essentially the same as the 
French official method* and differentiates cocoa and chocolate from 
cocoa shells more sharply than the A. O. A. C. method employing methyl 
orange as indicator. 

Determination of Protein. — Determine total nitrogen by the Kjeldahl 
or Gunning method. From the percentage of total nitrogen subtract 
the nitrogen of the theobromine and caffeine, obtained by multiplying the 
percentages found by 0.3 11 and 0.289 respectively, and multiply the 
remainder by 6.25. 




Fig. 79. — Cocoa. / entire fruit, Xi; II fruit in cross-section; 777 seed (cocoa bean) 
natural size; IV seed deprived of seed coat; V seed in longitudinal section, showing 
radicle (germ) ; VI seed in cross-section. (Winton.) 

Determination of Casein. — Hammarsten Method Modified by Baier 
and Neumann.1[ — Extract 20 grams of the sample with ether, dry at room 
temperature, and weigh. Rub up 10 grams of the dry fat-free material 
with a small quantity of 1% sodium oxalate solution, wash into a 250-cc. 
graduated flask with about 200 cc. of the oxalate solution, heat to boiling, 
and make up nearly to the mark with boiling oxalate solution. Allow to 
stand 18 hours with occasional shaking, fill to the mark with cold oxalate 
solution, and filter through a dry paper. Pipette off 100 cc. of the filtrate, 
add 5 cc. of 5% uranium acetate solution and 30% acetic acid, drop by 
drop with constant stirring until a precipitate of casein begins to form, 



* Ann. fals., 4, p. 417. 

t Zeits. Unters. Nahr. Genussm., 18, igog, p. 13. 



TEA, COFFEE, AND COCOA. 413 

then add 5 additional drops of the acid. Centrifuge, filter, wash free 
from oxalate with a solution containing in 100 cc. 5 grams of uranium 
acetate and 3 cc. of 30% acetic acid, and determine nitrogen in the filter 
and precipitate by the Kjeldahl or Gunning method. Calculate casein 
using the factor 6.37. 

Bolton and Revis * and Lythgoe f have found this method satisfactory. 

Determination of Theobromine and Cafifeine (Decker-Kunze MetJwd).X 
— This combination of the Decker and the Kunze methods was first em- 
ployed by Winton, Silverman, and Bailey, and afterwards adopted by 
the Assn. of Official x\gricultural Chemists. Boil 10 grams of the powdered 
material and 5 grams of calcined magnesia for 30 minutes with 300 cc. 
of water. Filter by the aid of suction on a Biichner funnel, using a round 
disk of filter paper. Transfer the material and paper to the same flask 
used for the first boiling, add 150 cc. of water, and boil 15 minutes. Filter 
as before, and repeat the operation of boiling with 150 cc. of water and 
filtering. Wash once or twice with hot water. Evaporate the united 
filtrates (with quartz sand if sugar be present) to complete dryness in a 
thin glass dish of about 300 cc. capacity. § 

Grind to a coarse powder in a mortar provided with a suitable cover 
to prevent loss by flying. Transfer to the inner tube of a continuous 
fat extractor, and dry thoroughly in a water oven. Extract with chloro- 
form for 8 hours, or until the theobromine and caffeine are completely 
removed, into a weighed flask. It is important that the material be 
thoroughly dry, that an extractor be used that permits of a hot extraction, 
and that a considerable volume of chloroform passes through the material. 
Distil off the chloroform, and dry at 100° C. to constant weight. 

If the material be pure chocolate or cocoa, the extract thus obtained 
is practically pure theobromine and caffeine, but if the material is cocoa 
shells or a cocoa product mixed with a large amount of shells, the extract 
may be brown in color, due to the presence of considerable amounts of 
impurities. 

In either case, separate the caffeine by treating the extract in the flask 
at the room temperature for some hours with 50 cc. of pure benzol. 

* Fatty Foods, Phila., 1913, p. 317. 

t Jour. Assn. Off. Agric. Chem., i, 1915, p. 200. 

X Schweiz. Wchschr. Phar., 40, 1902, pp. 527, 541, 553; Conn. Agric. Exp. Sta. Rep., 
1902, p. 274. 

§A "Hoffmeister Schalchen" may be used, or dishes may be made from broken flasks 
by making a scratch with a diamond and leading a crack from this scratch about the flask 
by means of a glowing springcoal. 



414 FOOD INSPECTION AND ANALYSIS. 

Filter through a small paper into a tared dish, evaporate to dryness, and 
dry to constant weight at ioo° C, thus obtaining the amount of caffeine. 

Determine theobromine by Kunze's * method, as follows: 

Add to the residue and paper 150 cc. of water, enough ammonia water 
to make the liquid slightly alkaline, and an excess of decinormal silver 
nitrate solution. Boil to half the original volume, add 75 cc. of water, 
and repeat the boiling. The solution should be perfectly neutral. If it 
contains the slightest amount of free ammonia, add water and boil until 
it is completely removed. 

Filter from the insoluble silver theobromine compound, and wash with 
hot water. In the filtrate determine the excess of silver nitrate by Vol- 
hard's f method as follows: 

Add 5 cc. of cold saturated solution of ferric ammonium sulphate 
(ferric-ammonium alum), and enough boiled nitric acid to bleach the 
liquid. Titrate with decinormal ammonium sulphocyanide solution until 
a permanent red color appears. 

One cc. of decinormal AgNOa solution is equivalent to 0.01802 gram 
of theobromine. If the mixed alkaloids were colorless, the theobromine 
obtained by subtracting the weight of caffeine from the weight of the 
mixed alkaloids will usually agree closely with that obtained by silver 
titration. 

Determination of Crude Fiber. — Proceed as in the analysis of cereal 
products, using the residue from the ether extraction. 

Determination of Reducing Matters by Acid Conversion (Crude 
Starch). — Winton, Silverman, and Bailey % proceed as follows: Weigh 
4 grams of the material into a small Wedgwood mortar, add 25 cc. of 
ether, and grind with a pestle. After the coarser material has settled 
out, decant off the ether with the fine suspended matter on an ii-cm.- 
paper. Repeat this treatment until no more coarse material remains. 
After the ether has evaporated, transfer the fat-free residue from the 
filter to the mortar by means of a jet of cold water, and rub to an even 
paste. Filter the liquid on the paper previously employed. Repeat the 
process of transferring from the filter to the mortar, grinding, and filtering, 
until all sugar is removed. In the case of sweetened cocoa products, 
at least 500 cc. of water should be used. 



* Zeits. anal. Chem., 2^, 1894. p. i. 

t Ibid., 13, i874,p. 171. 

t Conn. Agric. Exp. Sta., Rep., 1902, p. 275. 



TEA, COFFEE, AND COCOA. 415 

Transfer the residue to a 500-cc. flask by means of 200 cc. of water, 
and convert the starch into dextrose by Sachsse's method (page 292). 

Cool the acid solution, nearly neutralize with sodium hydroxide solu- 
tion, add 5 cc. of lead sub-acetate solution (page 610), make up to 250 
cc. and filter through a dry filter. To 100 cc. of the filtrate, add i cc. 
of 60% sulphuric acid, shake thoroughly, allow to settle, and filter through 
a dry filter. 

Determine reducing matters by Allihn's method (page 632). 

Dubois,"^ instead of treating with ether as above described, shakes 
4 grams of the unsweetened product or 8 grams of the sweetened with 
100 cc. of gasoline, and whirls in a centrifuge to separate from the insoluble 
matter. After decanting off the gasoline layer, sweetened products are 
treated in like manner with two portions of 100 cc. of water to remove 
the bulk of the sugar, and finally washed on the paper. 

Determination of Pure Starch. — Diastase Method. — Remove the fat 
and sugar from 4 grams of the material by treatment with ether and water, 
as described in the preceding section, and determine starch in the residue 
by the diastase method (page 292). 

Revis and Burnet ff employ a method with the following features: 
(i) taka-diastase is substituted for malt extract, (2) the solution containing 
dextrose and maltose into which the starch has been converted is cleared 
with acid mercuric nitrate, the excess being removed by sodium phosphate 
solution, (3) the copper-reducing power and polarization of the solution 
are determined without acid conversion, and (4) the dextrose and maltose 
and from these the starch are calculated by appropriate formulae. The 
authors obtain by this method lower results on cocoa shells than by the 
diastase method, which is consistent with the absence of starch as shown 
by microscopic examination. 

Determination of Pentosans.— See page 294. 

Determination of Sucrose and Lactose. — Dubois Method. % — Place 
26 grams of the material in an 8-ounce nursing bottle, add about 100 cc. 
petroleum ether and shake for 5 minutes. Whirl in a centrifuge until 
the solvent is clear, draw off the same by suction and repeat the treatment 
with petroleum ether. Keep the bottle containing the defatted residue 
in a warm place until the petroleum ether is practically expelled. Add 
ICO cc. water and shake until all the chocolate is loosened from the sides 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 214. 

t Analyst, 40, 1915, p. 429. 

X U. S. Dept. of Agric, Bur. of Chem., Circ. 66, p. 15. 



416 FOOD INSPECTION AND ANALYSIS. 

and bottom of the bottle and continue the shaking for 3 minutes longer. 
Add 10 cc. of lead subacetate solution (page 610), mix thoroughly and 
filter through a folded filter. Make the direct polariscopic reading (a) 
in a 200-mm. tube, then precipitate the excess of lead by dry potassium 
oxalate. Invert by one of the methods given on page 611, polarize, and 
multiply the invert reading by 2 to correct for dilution {b). Calculate 
the approximate percentages of sucrose (5) and lactose (L) by the follow- 
ing formulas: 

(a — b)Xiio (aXi.io)— 5 

142.60 — — 

2 

From the sum of 5 and L calculate the approximate number of grams 
of total sugar G present in the 26 grams of sample taken and determine 
the factor X thus: 

X=iio + (GXo.62), 

in which 0.62 is the volume in cc. displaced by i gram of sugar in water 
solution. Applying this correction, 

SX ^ ^ LX 

True per cent sucrose = — -. True per cent lactose = . 

^ no ^ no 

The following method of solution may be substituted for that given 
above : 

Transfer 26 grams to a flask, add 100 cc. water, cork, and heat in 
steam-bath for twenty minutes, releasing the pressure occasionally during 
the first five minutes. Twice during the twenty minutes shake thor- 
oughly so as to emulsify completely. Finally cool to room temperature, 
add 10 cc. lead subacetate solution, mix, and filter. 

Determination of Cocoa-Red. — Blyth Method.^ — Make 2-3 grams of 
the fat-free sample into a paste with hydrochloric acid, add sufficient 
silver oxide to fix the hydrochloric acid, and extract in a Soxhlet extractor 
with 100 cc. of absolute alcohol. Cool, filter the alcoholic liquid, pre- 
cipitate with an alcoholic solution of lead acetate, collect the purple-black 
precipitate on a filter, and wash well with boiling water. Transfer the 
precipitate to a small flask, add 70% alcohol, and decompose the lead 

* Blyth, Foods: Their Composition and Analysis, London, 1909, p. 368. 



TEA, COFFEE, AND COCOA. 417 

salt with hydrogen sulphide. Drive off the excess of hydrogen sulphide 
by heating, filter, evaporate the filtrate, dry, and weigh. Purify by con- 
verting again into the lead salt and decomposing with hydrogen sulphide. 

Zipperefs Method is more elaborate and requires correction for resin 
and phlobophene formed by the decomposition of the cocoa-red. 

Ulrich Method.'^ — Boil for 3 hours i gram of the dry, fat-free, finely 
powdered sample with 120 cc. acetic acid (50-51%) in a 300-cc. Erlen- 
meyer flask having a reflux condenser. Cool, make up to 150 cc. with 
water, shake, and allow to stand 12 hours. Filter through dry paper and 
boil 135 cc. of the filtrate with 5 cc. of concentrated hydrochloric acid 
and 20 cc. of a 20% ferrous chloride solution under a reflux condenser 
for 10 minutes. Cool quickly, pour into a beaker, allow to stand 6 hours, 
and filter through a weighed paper, washing with hot water until free 
from iron, dry 6 hours at 105° C, and weigh. 

ADULTERATION OF COCOA PRODUCTS AND STANDARDS OF PURITY. 

The following are the U. S. standards : f Standard chocolate should 
contain not more than 3% of ash insoluble in water, 3.5% of crude fiber, 
and 9% of starch, nor less than 45% of cocoa fat. 

Standard sweet chocolate and standard chocolate coating are plain 
chocolate mixed with sugar (sucrose), with or without the addition of 
cocoa butter, spices, or other flavoring material, containing in the sugar- 
and fat-free residue no higher percentage of either ash. fiber, or starch 
than is found in the sugar- and fat- free residue of plain chocolate. 

Standard cocoa should contain percentages of ash, crude fibe^, and 
starch corresponding to those of plain chocolate, after correcting for fat 
removed. 

Standard sweet cocoa is cocoa mixed with sugar (sucrose) containing 
not more than 60% of sugar, and in the sugar- and fat-free residue no 
higher percentage of either ash, crude fiber, or starch than is found in 
the sugar- and fat- free residue of plain chocolate. 

The removal of fat, or the addition of sugar beyond the above pre- 
scribed limits, or the addition of foreign fats, foreign starches, or other 
foreign substances, constitutes adulteration, unless plainly stated on the 
label. 



*Inaug. Dis. Detmold, 191 1; Arch. Pharm., 249, p. 524; Jour. Assn. Off. Agric. Chem., 
I, 1916, p. 550. 

t U. S. Dept. of Agric, Off. of Sec, Circ. 19. 



418 FOOD INSPECTION AND ANALYSIS. 

The most common adulterants of cocoa are sugar and various starches, 
especially those of wheat, corn, and arrowroot. Starch is sometimes 
added for the alleged purpose of diluting the cocoa fat, instead of remov- 
ing the latter by pressure, thus, it is claimed, rendering the cocoa more 
digestible and more nutritious. Unless its presence is announced on 
the label of the package, starch should be considered as an adulterant. 
Cocoa shells are also commonly employed as a substitute for, or an adul- 
terant of, cocoa. Other foreign substances found in cocoa are sand and 
ground wood fiber of various kinds. Iron oxide is occasionally used as 
a coloring matter, especially in cheap varieties. 

Such adulterants as the starches and cocoa shells are best detected by 
the microscope. The presence of any considerable admixture of sugar 
is made apparent by the taste. Mineral adulterants are sought for in 
the ash. 

Addition of Alkali. — The amount of water soluble matter in cocoa 
is very small (about 20 to 25%), and in preparing the beverage, 
the desideratum aimed at is to produce as perfect an emulsion as possible. 
The legitimate means of accomplishing this is by pulverizing the cocoa 
very fine, so that particles remain in even suspension and form a smooth 
paste. Another means sometimes resorted to for producing a so-called 
" soluble cocoa " is to add alkali in its manufacture, the effect being to 
act upon a part of the fat, and produce a more perfect emulsion with less 
separation of oil particles. Such treatment with alkali is regarded with 
disfavor, even if not considered as a form of adulteration. Cocoa thus 
treated is generally darker in color than the pure article. 

The use of alkali is usually rendered apparent by the abnormally high 
ash, and by the increased alkalinity of the ash, the latter constant being 
expressed in terms of the number of cubic centimeters of decinormal 
acid necessary to neutralize the ash of i gram of the sample. In pure, 
untreated cocoa, the ash rarely exceeds 5.5%, and the alkalinity of the 
ash is generally not more than 3.75. In cocoa treated with alkali, the 
ash sometimes reaches 8.5%, with the alkalinity running as high as 6 
or even 8. 

Microscopical Structure of Cocoa. — Fig. 80 shows elements of the 
powdered cocoa bean, both of the shell and of the kernel. The powder 
of the latter should constitute pure cocoa, with occasional fragments 
only of the shell. The irregular lobes constituting the kernel are each 
inclosed in a membrane made up of angular cells, filled with granular 
matter. (4), (5), and (6) show elements of the powdered cotyledons, 



TEA, COFFEE, AND COCOA. 



419 



or seed kernels. The polygonal tissue of the cotyledon is shown in cross- 
section at (4). In the powder one finds also dark granular matter, bits 
of debris, and fragments, with masses of yellow, reddish-brown, and 
sometimes violet coloring matter, together with numerous starch granules 
and aleurone grains. 

The starch granules are nearly circular, with rather indistinct central 
nuclei, and range in size from 0.0024 to 0.0127 mm., averaging about 
0.007 ™^- They are more often found in single detached grains, but 
sometimes in groups of two or three. Occasional ^spiral ducts, sp, are 
seen, but these are not abundant in the pure cocoa. 





Fig. 80. — Cocoa under the Microscope. 

A. Powdered Cocoa under the Microscope. X125. (After Moeller.) i, cross-section 
through shell parenchyma; 2, thick-walled cells; 3. epidermis of shell (surface section); 
4, cross-section of cotyledon tissue; 5, 6, cotyledon parenchyma; 7, starch. 

B. Cocoa Shell in Surface Section. X160. ep, epicarp; p, parenchyma of the fruit; 
qu, layer of transverse cells. (After Moeller.) 

The masses of color pigment are shown up with striking clearness, 
according to Schimper, by applying a drop of sulphuric acid to the edge 
of the cover-glass and allowing it to penetrate the tissue. The bits of 
coloring matter are for a short time colored a brilliant red, which, how- 
ever, soon fades. Ferric chloride colors them indigo blue. 

Schimper recommends mounting the powder in a drop of chloral 
hydrate, which soon renders most of the tissues transparent. It is some- 
times necessary to allow the chloral to act on the powder in a closed 



420 FOOD INSPECTION AND ANALYSIS. 

vessel for twenty-four hours, before all the elements of pure cocoa are 
rendered transparent. If after that time opaque masses are still found, 
these are due to foreign material. 

Ammonia may be used instead of chloral with even better results, 
but this reagent requires longer treatment, soaking for several days or 
a week being sometimes necessary. 

Fig. 185, PI. XVII, shows the microscopical appearance of genuine 
powdered cocoa .with its variously sized starch grains and the debris of 
the ground cotyledons. Fig. 186 shows cocoa adulterated with arrowroot. 

Cocoa Shells. — A cross-section of the shell parenchyma and the stone- 
cell layer, also some of the numerous spiral ducts, all characteristic of the 
ground shell, are shown at i. Fig. 80. 

The thick-walled stone-cells are shown in surface view at 2, and 
the spongy, outer seed-skin, composed of two layers, with elongated 
cells running crosswise to each other in striated fashion, and with the 
underlying hairs or so-called " Mitscherlich bodies," is shown at 3. 
The presence of an abnormally large number of yellow and brown frag- 
ments in the water-mounted cocoa specimen, even under small magnifi- 
cation, arouses suspicion of the presence of shells, the most distinctive 
elements of which are the spongy tissue, the stone-cells, and the abundant 
spiral ducts, the latter being scarce in pure cocoa powder. 

Cocoa shells are indicated on chemical analysis by the abnormally 
high ash, crude fiber and pentosans. 

Added Starch. — This can only be approximately determined by a 
careful examination with the microscope. Long experience will enable the 
analyst to familiarize himself with the appearance and abundance of 
starch grains of various kinds in a series of fields, so that he can roughly 
estimate the amount of each starch present in the mixture, by careful 
comparison with mixtures of known percentage composition. 

If the amount of starchy adulterant is considerable, evidence may be 
secured by determinations of starch by the diastase method and reducing 
matters by acid conversion. 

Added Sugar.— Any appreciable amount of added cane sugar is shown 
by the sweet taste. The amount of cane sugar may be determined by 
means of the polariscope, as described on page 415. 

An abnormally low ash is indicative of the addition of starch or 
sugar or both. 

Foreign Fat.— Certain mnaufacturers have found it profitable to 
remove a portion of the cocoa butter from chocolate and substitute for 



TEA, COFFEE, AND COCOA. 421 

it a cheaper fat, such as cocoanut oil, tallow or even paraffine. Such 
adulteration is detected by determination of the physcial and chemical 
constants of the fat obtained by extraction with ether. 

Dyes and Pigm3nts, such as Bismarck brown and Venetian red, have 
been employed to hide the presence of diluents. They are detected by 
dyeing tests, and by examination of the ash. 



CHAPTER XII. 
SPICES. 

These aromatic vegetable substances are classed as condiments, and 
depend for their use on the pungency which they posses in giving flavor 
or relish to food. As such seasoning or zest-giving substances, they are 
of considerable importance dietetically, but from the fact that they are 
used in comparatively insignificant amount, the determination of their 
chemical composition or actual value as nutrients per se is of little im- 
portance to the food economist. 

Adulteration. — Formerly ground spices were subject to the grossest 
forms of adulteration, all kinds of cheap material being reduced to powders 
for the purpose, the aim being to match the genuine spice in color and 
general appearance. The foreign materials were for the most part de- 
tected by microscopic examination although chemical analysis furnished 
valuable corroboratory evidence. At present such frauds have for the 
most part disappeared in the United States, and the analyst is called 
on chiefly to examine spices for an excess of shells or fibrous material, dirt, 
and similar impurities, the presence of which indicates a low grade rather 
than intentional adulteration, or for exhausted spices. 

In a few instances the substitution of the products of inferior species 
or varieties belonging to the same family as those which yield the standard 
spice is still practiced. Examples are Bombay and Macassar mace sub- 
stituted for true or Banda mace, the seed of charlock substituted for the 
seeds of the more valuable species of the mustard family, and Spanish 
red pepper or pimiento substituted for the Hungarian product known as 
paprika. 

Microscopic and chemical examination is still necessary partly to 
detect the occasional fraud of the old type, which still may be practiced, 
and partly to distinguish varieties and grades and detect an excess of 
natural impurities. 

General Methods of Proximate Analysis. — The following methods 
common to all the spices are specially designed to determine quality or 
grade, or to detect adulteration. 

Methods of analysis peculiar to individual spices will be treated 

422 



1 



SPICES. 423 

under the discussion of the spice in question. For these determinations 
the spices should be powdered fine enough to pass through a 6o-mesh 
sieve. 

Determination of Moisture. — Richardson'' s Method.^ — Two grams of the 
sample are weighed in a tared platinum dish and dried in an air-oven 
at iio° to a constant weight, which generally requires about twelve hours. 
The loss in weight includes the moisture and the volatile oil. The latter 
is determined from the ether extract, as described on page 424, and 
deducted from the total loss to obtain the moisture. 

McGill t determines the moisture by exposure of a weighed portion 
of the sample in vacuo over perfectly colorless sulphuric acid. The spice 
gives up its moisture before the volatile oil comes off, and any appreciable 
amount of the volatile oil, when absorbed by the acid, causes the latter 
to be discolored, so that by carefully observing the beginning of the dis- 
coloration, and removing the sample, the loss due to moisture may be 
obtained by weighing at the proper stage. The abstraction of the mois- 
ture in ihis manner requires about twenty-four hours. 

Determination of Ash. — Two grams of the spice are burned in a 
platinum dish heated to faint redness on a piece of asbestos paper by 
means of a Bunsen burner. The burning is best finished in a muffle 
furnace. If the ash contains an appreciable amount of carbon, it is 
exhausted on a filter with hot water, and the filter with the residue is 
burnt in the dish previously used. After adding the aqueous extract 
and a few drops of ammonium carbonate solution, the whole is evaporated 
to dryness and ignited at a faint red heat. 

The Water-soluhle Ash % is found by boiling the total ash as above 
obtained with 50 cc. of water, and filtering on a tared Gooch crucible, 
the insoluble residue being washed with hot water, dried, ignited, and 
weighed. The insoluble ash, subtracted from the total, leaves the water- 
soluble ash. 

Sand. — This is assumed to be the percentage of ash insoluble in 
hydrochloric acid. The ash from 2 grams of the substance, obtained as 
above described, is boiled with 25 cc. of 10% hydrochloric acid (specinc 
gravity 1.050) for five minutes, the insoluble residue is collected on a 
tared Gooch crucible, thoroughly washed with hot water, and finally 
dried and weighed. 

* U. S. Dept. of Agric, Div. of Chem., Bui. 13, pt. 2, p. 165. 
t Canada Dept. of Inland Rev., Bui. 73, p. 9. 
X Conn. Agric. Exp. Sta., Rep. 1898, p. 186. 



424 FOOD INSPECTION AND ANALYSIS. 

Lime is determined from the ash as directed on page 312, having first 
separated the iron and phosphates. 

The sulphuric acid due to calcium sulphate (added as an adulterant) 
is determined by precipitation with barium chloride of a very weak hydro- 
chloric acid solution of the ash, the separated barium sulphate being 
washed, dried, ignited and weighed. 

Ether Extract. — Total, Volatile, and Non-volatile* — Two grams of the 
air-dry, • powdered substance are placed in some form of continuous 
extraction apparatus, such as Soxhlet's or Johnson's (Chapter IV), 
and are subjected to extraction for sixteen hours with anhydrous, alcohol- 
free ether.t The ether solution is then transferred to a tared evaporating- 
dish, and allowed to evaporate spontaneously at the temperature of the 
room. After the disappearance of the ether, the evaporating-dish is 
placed in a desiccator over concentrated sulphuric acid and left over 
night, or for at least twelve hours, after which it is weighed, the residue 
in the dish being regarded as the total ether extract. 

The dish and its contents are then subjected to a heat of about 100° C. 
for several hours, taking a long time to bring the temperature up to that 
point so as to avoid oxidation of the oil. Finally heat at 110° C. till the 
weight is constant. The final residue is the non- volatile, and the loss 
in weight the volatile ether extract. 

Alcohol Extract. — Method 0} Winton, Ogden, and Mitchell.X — Two 
grams of the powdered sample are placed in a loo-cc. graduated flask, 
which is filled to the mark with 95% alcohol. The flask is stoppered and 
shaken at half-hour intervals during eight hours, after which it is allowed 
to stand for sixteen additional hours without shaking, and the contents 
poured upon a dry filter. Of the filtrate, 50 cc. are evaporated to dry- 
ness in a tared platinum dish on the water-bath, and heated at 110° C. 
in an air-oven to constant weight. This method, while only approxi- 
mate, is so much simpler than the tedious operation of continuous extrac- 
tion, considering the long time required, that it is regarded as preferable 
for ordinary work, and, unless great care is taken, is nearly as accurate. 

Determination of Nitrogen. — This, in spices other than pepper, is 
best done by means of the Gunning or Kjeldahl method. 



* Richardson, U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 165. 

t Petroleum ether may be used, yielding results which differ but slightly from those 
obtained with ethyl ether. As the latter has been used in the analyses of a large number 
of samples of spices, if these analyses are to be taken for standards of comparison it is evi- 
dent that the same solvent should be used. 

X Conn. Agric. Exp. Sta., Rep. 1898, p. 187. 



SPICES. 425 

Determination of Starch. — In spices like white pepper, ginger, and 
nutmeg that normally contain a high content of starch and very little 
other copper-reducing matter, the direct acid conversion process of starch 
determination is satisfactory. 

In spices normally free from starch, such as cloves, mustard, and 
cayenne, vv^here a starch determination indicates the amount of a foreign 
starch present as an adulterant, it is safer to use l^he diastase process. 

Four grams of the powdered sample are extracted on a filter-paper 
(fine enough to retain all starch particles) first with five successive por- 
tions of ID cc. of ether, then with 150 cc. of 10% alcohol. Owing to 
difficulty of filtering in the case of cassia and cinnamon, Winton recom- 
mends that all washing in the determination of starch in these substances 
be omitted. The residue is washed from the filter-paper by means of 
a stream of water into a 500-cc. flask, if the direct acid conversion method 
is used, using 200 cc. of water; 20 cc. of hydrochloric acid (specific 
gravity 1.125) are added, and the method from this point on followed^ 
as detailed on page 292. 

If the starch is to be determined by the diastase method, wash the 
residue from the filter-paper into a beaker with 100 cc. of water, and 
proceed as on page 292. 

Determine the dextrose in either case by the Defren or Allihn method* 
or volumetrically, and convert dextrose to starch by the factor 0.9. 

Determination of Crude Fiber. — Two grams of the substance are 
extracted with ordinary ether (or the residue left from the determination 
of the ether extract may be taken) and subjected to the regular method 
for determining crude fiber, by boiling successively with acid and alkali 
(page 286). 

McGill recommends the use of the centrifuge in separating the crude 
fiber, after boiling with the alkaline solution. 

Determination of Volatile Oil. — Method 0} Girard and Dupre* — 
The spice is mixed with water and subjected to distillation, receiving 
the distillate in a graduated cylinder. The volume occupied by the 
essential oil (which is immiscible with water) can be thus rea-d off and 
its content roughly determined. If the volatile oil is slightly soluble 
in water, separate out the water layer, having first read the volume of 
the oil layer, and extract the aqueous solution with petroleum ether. 
Evaporate the petroleum ether extract to dryness at room temperature 

* Analyse des Matieres Alimentaires, 2nd ed., p. 787. 



426 FOOD INSPECTION AND ANALYSIS. 

in a tared dish, and add the volume due to the weight of the residue to 
the volume read off in the graduate. 

Microscopical Examination of Powdered Spices. — As a rule few 
microscopical reagents are necessary in the routine examination of 
powdered spices for adulteration, unless a more careful study of the 
structure than is necessary to prove the presence of adulterants is desir- 
able. The simple water-mounted specimen is usually sufficient to show 
the purity or otherwise of the sample. If in doub. as to the presence oi 
starch in small quantities, iodine in potassium iodide should be apphed 
to the specimen, well rubbed out under the cover-glass. 

The tissues may be cleared by adding to the water mount a small 
drop of 5% sodium hydroxide, or by soaking a portion of the spic? for a 
day in chloral hydrate solution. A valuable means of clearing dense 
tissues is to boil about 2 grams of the material successively with dilute 
acid and alkali as in the crude fiber process (p. 286), decanting (not 
filtering) the solution after each boiling. 

The presence of occasional traces of a foreign substance, when viewed 
under the microscope, is hardly sufficient to condemn the sample as 
adulterated, since such traces are apt to be accidental. 

Composition of Miscellaneous Spice Adulterants. — The chemical 
analyses of various spice adulcerants commonly met with are given on 
page 427. 

CLOVES. 

Nature and Composition. — Cloves are the dried, undeveloped flowers 
of the clove tree {Caryophyllus aromahcus or Eugenia caryo phyllata) , 
which belongs to the myrtle family {Myrtacece). The tree is an evergreen, 
from twenty to forty feet in height, cultivated extensively in Brazil, Cey- 
lon, India, Mauritius, the West Indies, and Zanzibar. Its leaves are 
from 7.5 to 13 mm. long, and its flowers, of a purphsh color, grow in 
clusters. The green buds in the process of growlih change to a reddish 
color, at which stage they are removed from the tree, spread out in the 
sun, and allowed to dry, the color changing to a deep brown. Each 
whole clove consists of a hard, cylindrical calyx tube, having at the top 
four branching sepals, surrounding a ball-shaped casing, which consists 
of the tightly overlapping petals, and within which are the stamens and 
pistil of the flower. In taste the clove possesses a strong and pecuhar 
pungency. One of its most valuable ingredients is the volatile clove 
oil. This is composed largely of eugenol (CioHijOj), which forms 70 to 



i 



SPICES. 



427 



COMPOSITION OF SPICE' ADULTERANTS. 



English-walnut shells*. 

Brazil-nut shells * 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones f . 
Buckwheat hulls 



Ash. 



1.40 

1-59 
2.86 

0-54 
1.24 
0.23 
1.22 

5-72 
8.40 
0.70 
0.88 

1.84 



1^ 



0.77 

1.06 

2-39 
0.50 
0.76 
o. 16 
0.32 

1-74 
4.66 
0.28 
0.24 

i.r4 






0.00 
0.17 
0.05 
0.00 
0.04 
0.00 
0.02 

0-55 
0.83 
0.07 
0.44 

0.00 



Ether Extract. 



0.07 
0.16 
0.00 
0.36 
0.07 
0.07 
0.04 
1. 00 
I .21 
0.06 
0.07 



C.2 



0-55 
0-57 
0.64 
0.25 
8.38 
0.77 
C.84 
6.58 
2.99 
11.47 
0.24 
0.38 



1.84 
1. 01 
5.16 
1. 12 

16.72 
1.50 
6.25 
9.46 
4-77 

19-37 

2.17 



English-walnut shells *. 

Brazil-nut shells * 

Almond shells * 

Cocoanut shells * 

Date stones * 

Spruce sawdust * 

Oak sawdust * 

Linseed meal * 

Cocoa shells * 

Red sandalwood * 

Ground olive stones f . 
Buckwheat hulls 



Sf <n o .; 



19.30 
12.96 
22.72 
20.88 
20.88 
15.48 
17.10 
21.11; 

8.68 
6.79 



20.51 



1. 01 

0-73 
0.84 

0-73 
2.19 

1-13 

1.68 

14.06 

3-15 
1. 12 

1-73 
1.46 



56.58 
50.98 
49.89 
56.19 

5-72 
64.03 

47-79 

8.30 

14.12 

52-30 
57-46 
43-76 



1.69 
4.19 
1-75 
I -13 
5-31 
0.56 
1.63 
31.81 
16.19 
3.06 
1.06 
^.06 



a; u a> 5 
>.i? crx 



0-53 
0-33 
0.40 
0.47 
0.61 
0.30 

1. 00 
1 .26 
0-59 



S-0-? 



O' 



1.30 
1.56 
1.82 

2.34 
1. 17 
12.22 
3-90 
4-94 
2.29 



0.27 
0.67 
0.28 
C.18 
0.85 
0.09 
0.26 
5-09 

2-59 
0.49 
0.17 
0.49 



85 per cent of the oil, and a sesquiterpene known as caryophyllene. 
There are also in cloves a notable amount of fixed oil and resin, and also 
a peculiar form of tannin. 

Very few complete analyses of cloves are on record. Richardson f 
seems to have been the earliest worker in the field to give anything at 
all satisfactory in the way of a number of determinations of value. 

The following are maximum and minimum figures from the tabu- 
lated results of Richardson's analyses: 

* Winton, Ogden, and Mitchell, Conn. Exp. Sta. An. Rep., 1898, p. 210. 
t Doolittle, Mich. Dairy and Food Dcpt. Bui. 94, 1903, p. 12. 
J U. S. Dept. of Agric, Div. of Chem., Bui. 13. 



428 



FOOD INSPECTION AND ANALYSIS, 



Whole cloves (7 samples): 

Maximum 

Minimum 

Stems ( I sample) 

Ground cloves (9 samples): 

Maximum 

Minimum 



10.67 
2.90 
10. 1 



13-05 
5-50 
6.96 



9-5810.73 
5-93 5-79 



0.23 
4.40 



13-93 
3-94 



Oii 



10.24 

7- 
4-03 

7-44 
4.02 



9-75 
6.18 

13-58 

13.80 
9-38 



7- 

4-73 

5-78 

6.48 
4.20 






1. 12 
.76 
.92 

1.04 

.70 



5-43 
3.00 

5-96 
6.20 






22.13 
11.70 
23.24 

24.18 



McGill * gives tables of analyses of pure and adulterated samples of 
cloves. Analyses of upwards of twenty samples of genuine cloves, both 
whole and ground, from these tables show the following maximum and 
minimum figures: 



Moisture 

Volatile oil 

Total volatile matter 

Fixed oil 

Total extraction 

Ash 



Maxi 



Minim-iim. 



11.80 
19.63 
30.68 
10.23 

31-40 
7.00 



5-05 

9.24 
16.25 

0.94 
22.23 

5-03 



McGill also made analyses of whole cloves of several varieties, the 
fcilowing table being a summary of his results: 



No. of 
Analyses. 





Total 


Moisture. 


Volatile 




Matter. 


7-4 


24-3 


5-0 


20.7 


6.2 


22.4 


6-7 


25-9 


5-S 


23-5 


6.1 


24.6 


6.7 


23.6 


4.1 


18.6 


5-7 


21.7 



Volatile 
Oil. 



Total 
Extract- 
ive 

Matter. 



Fixed 
Oil. 



Penang cloves: Maximum 

Minimum. 

Mean 

\mboyna cloves: Maximum 

Minimum. 

Mean 

Zanzibar cloves: Maximum 

Minimum. 

Mean. 



17.2 
14.8 
16.2 
19.2 
18.0 
18.5 

18.3 
12. 1 
16.0 



28.2 
24.4 
27.0 
29.2 
26.5 

27-5 
28.1 

21.3 

25-5 



9-5 
10.8 



9-0 
10.7 
8.0 



Maximum and minimum figures of thirteen samples of unadulterated 
cloves, as purchased from retail dealers in Connecticut and analyzed 
by Winton and Mitchell,! are as follows: 

* Canada Inland Rev. Dept. Bui. 73. 

\ Conn. Exp. Sta. Rep., 1898, pp. 176-177 



SPICES. 



429 





Maximum. 


Minimum. 


Ash total . . . 


7.92 

18.25 

7.19 


5-99 

11.03 

4.87 


Ether extract, volatile ......... 







Winton, Ogden, and Mitchell * give more complete analyses of eight 
samples of whole cloves of known purity, representing Penang, Amboyna, 
and Zanzibar varieties, and two samples of clove stems, as follows: 





Moisture. 


Ash. 


Ether Extract. 






Total. 


Soluble in 
Water. 


Insoluble 
in HCl. 


Volatile. 


Non- 
volatile. 


Extract. 


Maximum 


8.26 

7-03 
7.81 

8.74 


6.22 

5.28 
5-92 
7-99 


3-75 
3-25 
3-58 
4.26 


0.13 
0.00 
0.06 
0.60 


20.53 
17.82 
19.18 

5.00 


6.67 
6.24 
6.49 
3-83 


is-58 


Minimum 


13-99 




14.87 


Clove stems, mean 


6.79 




Reducing 
Matters 
by Acid 
Conver- 
sion, as 
Starch. 


Starch by 
Diastase 
Method. 


Crude 
Fiber. 


Nitrogen, 
X6.2S. 


Oxygen 
Absorbed 
by Aque- 
ous Ex- 
tract. 


Querci- 

tannic 
Acid. 


Total 
Nitrogen. 


Maximum ............ 


9-63 
8.19 

8-99 
14-13 


3-15 
2.08 

2-74 
2.17 


9.02 

7.06 

8.10 

18.71 


7.06 
5-88 
6.18 
5.88 


2.63 
2.08 

2-33 
2.40 


20-54 
16.25 
18.19 
18.79 


I-I3 


M inimum 


0.94 


Mean 


0.99 


Clove-stems, mean 


0.94 



The Tannin Equivalent in Cloves. — The amount of tannin in cloves 
was shown by ElUs to be so constant as to be of valuable assistance as a 
guide to their purity. The actual determination of tannin is, however, 
a long and difficult proceeding, and Richardson f has pointed out that 
it is not necessary, but that simply using the first part of the Lowenthal 
tannin process, and noting the "oxygen absorbed" as expressed by the 
oxidizing power of permanganate of potash on the material after extrac- 
tion with ether, is quite as useful as determining the tannin, and is in 
effect proportional to the tannin present. The result is sometimes 
expressed as in Richardson's figures above, as the oxygen equivalent, or 
as quercitannic acid. 

Determination of Tannin Equivalent.^ — Reagents: Indigo Solution. — 
Six grams of the indigo salt § are dissolved in 500 cc. of water by heat- 

* Conn. Exp. Sta. Rep., 1898, pp. 206, 207. 

t U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 167. 

X U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 60; Bui. 107 rev., p. 164. 

§ The quality of the indigo used is of great importance since with inferior brands it is 



430 FOOD INSPECTION AND ANALYSIS. 

ing. After cooling, 50 cc. of concentrated sulphuric acid are added, 
the solution made up to a liter and filtered. 

Standard Permanganate Solution. — Dissolve 1.333 grams of pure 
potassium permanganate in a Hter of water. This should be standardized 
by titrating against 10 cc. of tenth-normal oxaHc acid (6.3 grams pure 
crystalHzed oxahc acid in 1,000 cc), diluted to 500 cc. with water, heated 
to 60° C, and mixed with 20 cc. of dilute sulphuric acid (i : 3 by volume). 
The permanganate solution is added slowly, stirring constantly, till a 
pink color appears. 

Two grams of the material are extracted for twenty hours with pure 
anhydrous ether. The residue is boiled for two hours with 300 cc. of 
water, cooled, made up to 500 cc, and filtered. 

Twenty-five cc. of the filtrate are pipetted into a 1200-cc. flask, 750 cc. 
of distilled water are added and 20 cc. of indigo solution. 

The standard permanganate solution is then run in from a burette 
a drop at a time with constant shaking, until a bright golden yellow color 
appears, which indicates the end-point. Note the number of cubic cen- 
timeters required, represented by {a). 

In a similar manner determine the number of cubic centimeters of 
standard permanganate solution consumed by 20 cc. of the indigo solu- 
tion alone, represented by (ft), and subtract this from (a). 

The oxygen equivalent, or, as it is sometimes called, the "oxygen 
absorbed," is calculated from the equivalent in tenth-normal oxalic acid 
of the number of cubic centimeters of standard permanganate repre- 
sented by a — h. 10 cc of tenth-normal oxalic acid are equivalent to 
0.008 gram of oxygen absorbed, or 0.0623 gram of quercitannic acid. 

Microscopical Examination of Cloves. — Unless the finely powdered, 
water-mounted sample is well rubbed out under the cover-glass, many 
of the masses of cellular tissue will be too dense to recognize. With a 
little care, however, it is possible to make a very satisfactory water mount, 
though by soaking for twenty-four hours in chloral hydrate solution the 
more opaque masses are rendered very translucent. 

Fig. 81, from Moeller, shows some of the characteristics of p-^wdered 
cloves. The outer skin of the calyx tube is shown at (i) with its polyg- 
onal cells and large oil spaces showing through them; (2) shows the 
epidermis of the outer part of the lobes or wings of the calyx, with stomata 

impossible to get a sharp end-point. The indigo solution should be made from the very 
best variety of sulphindigotate, which may be obtained from Grueber & Co., of Leipzig, or 
Gehe & Co., of Dresden, under the name of canniniuni cceruleum. 



SPICES. 



431 



surrounded by irregularly shaped cells; (3) represents the epidermis 
of the petals, with crystals of calcium oxalate; a cross-section of the epi- 
dermis of the calyx is shown at (4); (5) shows the parenchyma, with 
calcium oxalate crystals and with one of the slender spiral ducts; (6) 
and (7) represent in cross-section and longitudinal section respectively 
the parenchyma of the middle layers of the ovary, one of the rounded, 
triangular pollen grains being shown at (12). 




5 ' ^ KJ^-J 
Fig. 8 1 .—Powdered Cloves under the Miaroscope. X125. (After Moeller.) 

Characteristics of clove stems, which are frequently used as adulter- 
ants of cloves, are found in (8), (9), (10), and (11). Stone cells of 
the outer skin and the inner portion of the clove stem are shown 
at (8) and (9) respectively; (10) shows one of the vascular ducts, 
and (11) two of the bast fibers. Both the vascular ducts and the 
stone cells are very characteristic of clove stems. Pure cloves have no 
stone cells and comparatively few bast fibers. Stemj under the micro- 
scope show a large number of bast fibers and frequent stone cells, the 
latter being of a distinctly yellow color. 

A plain water-mounted slide rarely shows all the structural details 
depicted in Fig. 81, but is nearly always sufficiently characteristic to 



432 FOOD INSPECTION AND ANALYSIS. 

prove the purity of the sample. Fig. 220, PI. XXV, shows the actual 
appearance of powdered cloves, mounted in water and examined under 
a magnification of 130. The general appearance of the cellullar tissue 
is that of a loose, spongy mass filled with brown, granular material. 
Throughout the masses of tissue are to be seen small oil globules. 

Cloves have no starch whatever. Aside from the stems, cloves 
are sometimes adulterated with clove fruit or " mother cloves," which 
have a small amount of a sago-like starch, and also contain some stone 
cells. 

The U. S. Standard for pure cloves is as follows: Clove stems not more 
than 5%; volatile ether extract not less than 15%; quercitannic acid, 
calculated from the total oxygen absorbed by the aqueous extract, not 
less than 12%; total ash not more than 7%; ash insoluble in hydrochloric 
acid not more than 0.5%; crude fiber not more than 10%. 

Adulteration of Cloves. — Clove Stems are frequently present in cloves 
and possess considerable pungency. They are commonly identified under 
the microscope by the large number of bast fibers and stone cells. 

Allspice, being considerably cheaper than cloves, is sometimes used 
as an adulterant. It is readily recognized by the characteristics described 
on page 436. 

O titer Adulterants reported in cloves are cereal products (especially 
corn and wheat) and ginger (for the most part " exhausted"). Besides 
the above, pea starch, rice, turmeric, charcoal, sand, pepper, ground 
fruit stones, and sawdust have been found in samples of cloves examined 
in Massachusetts. 

Exhausted Cloves, both whole and in powdered form, are not infre- 
quently found on the market. These have been deprived of a portion 
of the volatile oil, and are much less pungent than the pure article, so 
that the difference in taste between the two varieties is quite marked. It 
is, however, rare that powdered cloves are sold consisting entirely of 
the exhausted variety, the more common practice being to mix from 
10 to 25% of exhausted cloves with the pure powder, so that the sophistica- 
tion is less apparent. 

A determination of the volatile oil is the only reliable means of show- 
ing whether or not the material has been wholly or in part exhausted, 
though Villiers and Collin claim that under the microscope an exhausted 
sample of cloves shows the oil glands to be nearly empty, or to inclose 
much smaller droplets of oil than the pure variety. 



SPICES. 



433 



With the exception of exhausted cloves, the presence of nearly 
every foreign ingredient is best and most quickly shown by the use of 
the microscope, though much information as to the purity of the sample 
can be gained by the ether extract, the percentage of ash, and of crude 
fiber.* 

Cocoanut Shells. — Figs. 226 and 227, PL XXVII, show samples of cloves 
adulterated with ground cocoanut shells. The long, spindle-shaped, yellow- 
brown and deeply furrowed stone cells of the adulterant with their thick 
walls and central branching pores are unmistakable. The dark-brown 
contents of the cells turn reddish brown when treated with potassium 
hydroxide. The anatomy of the cocoanut, including the shell, has been 
carefully studied by Winton.f 

Fig. 82, after Winton, shows elements of powdered cocoanut shell 
under the microscope, st are the daik, elongated, yellow, porous ston© 



-^ 




Fig. 82. — Cocoanut-shell Powder. s(, dark-yellow stone cells with brown contents; 
t, reticulated trachea; sp, spiral trachea; g, pitted trachea; w, colorless, and br, 
brown, parenchyma of mesocarp; /, bast fibres, with stegmata (ste). Xi6o. (After 
Winton.) 

cells with their brown contents, these stone cells being the most dis- 
tinctive characteristic of the ground shells. /, sp, and g are the various 
forms of trachea; w and hr are respectively colorless and brown paren- 
chyma of the mesocarp or outer coat, portions of which always adhere 
to the nutshell and are ground with it. 

* Note especially the sharp distinction between these values in the case of pure cloves 
and of clove stems in Richardson's table. 

I The Anatomy of the Fruit of the Cocoanut. Conn. Exp. Sta. Rep., 1901, p. 208. 



434 



FOOD INSPECTION AND ANALYSIS. 



Fig. 264, PI. XXXVI, shows a photomicrograph of powdered cocoanut 
shells, mounted in gelatin. The long, spindle-shaped stone cells are 
especially apparent, 

Ground cocoanut shells have been used in various spices besides 
cloves, especially allspice and pepper. In the following tabulated 
results of analyses by Winton, Ogden, and Mitchell * are shown the wide 
deviation between the chemical constants of cocoanut shells and several 
of the spices in which they appear as adulterants. 



Water 

Total ash. 

Ash soluble in water 

Ash insoluble in hydrochloric acid 

Volatile ether extract 

Non-volatile ether extract 

Alcohol extract 

Reducing matters, as starch, acid conversion 

Starch by diastase method 

Crude fiber 

Total nitrogen 

Oxygen absorbed by aqueous extract 

Quercitannic acid equivalent 



Black 
Pepper. 


Cloves. 


Allspice. 


Nutmeg. 


11.96 


7.81 


9.78 


3.63 


4.76 


5-92 


4 


47 


2.28 


2-54 


3-58 


2 


47 


0.86 


0.47 


0.06 





03 


0.00 


1. 14 


1Q.18 


4 


o.S 


3.02 


8.42 


6.49 


5 


84 


36.70 


g.62 


14.87 


II 


79 


10.77 


38.63 


8.99 


18 


03 


25-56 


34-15 


2.74 


3 


04 


23-72 


13.06 


8.10 


22 


39 


2.51 


2.26 


0.99 





92 


1.08 




2.33 


I 


24 






18.19 


9 


71 





Cocoanut 
Shells. 



7-36 
0-54 
0.50 
0.00 
0.00 
0.25 
I. 12 
20.88 

0.73 
56.19 
0.18 
0.23 
1.83 



ALLSPICE, OR PIMENTO. 

Nature and Compositicn. — Allspice is the dried fruit of the Eugenia 
pimenta, an evergreen tree belonging to the same family (MyrtncecB) 
as the clove. It is indigenous to the West Indies, and is especially cul- 
tivated in Jamaica. 

The allspice berry is grayish or reddish brown in color, and is hard 
and globular, measuring from 4 to 8 mm. in diameter, being surmounted 
by a short style. This is imbedded in a depression, and around it are 
the four lobes of the calyx, or the scars left by them after they have fallen 
off. The berry has a wrinkled, ligneous pericarp, with many small 
excrescences filled with essential oil. The pericarp is ea.sily broken 
between the fingers, showing the berry to be formed of two cells with a 
single, brown, kidney-shaped seed in each, covered with a thin, outer 
coating, inclosing an embryo rolled up in a spiral. 

The berries are gathered when they have attained their largest size, 
but before becoming fully ripe. If allowed to mature beyond this stage, 
some of the aroma is lost. 



* Conn. Ag. Exp. Sta. Rep., 1901, p. 225. 



SPICES. 



435 



Though considerably less pungent than other spices, allspice possesses 
an aroma not unlike cloves and cassia. In chemical composition it most 
resembles cloves, containing both volatile oil and tannin ; but, unhke 
cloves, it contains much starch, the starch being contained in the seeds. 
The volatile oil of allspice is very similar to clove oil. It is shghtly laevo- 
rotary. and is composed of eugenol and a sesquiterpene not determined. 
It is present in allspice to the extent of 3 to 4.5 per cent. The boiling- 
point of the oil is 255° C. 

Authoritative full analyses of allspice are even more meager than 
of cloves. Analyses of one sample of whole allspice and five samples 
of the ground spice, made by Richardson,* are thus summarized: 











































c 


■d 






< 


.5J 

|5 


1° 






k 


s 

■*-> 


Tannin 
Equival 




Whole 


6.19 


4.01 


5-15 


6.15 


59.28 


14.83 


4-38 


.70 


10.97 


2 81 


Ground: 




Maximum 


8.82 


5-53 


7>-^2 


6.92 


58.24 


18.98 


5-42 


.87 


12.74 


3-36 


Minimum 


5-51 


3-45 


2.07 


3-77 


56.86 


13-45 


4-03 


.64 


8.27 


2.12 



Seventeen samples of unadulterated allspice, as sold on the Connect- 
icut market, were analyzed by Winton and Mitchell,! with maximum 
and minimum results as follows: 



Ash. 


Maximum. 


Minimum. 


Total 


7-51 

-95 
3-50 
6.22 


4-34 
.40 

1-34 
3-78 


Insoluble in hydrochloric acid (sand) . . 
Ether extract, volatile 


Ether extract, non-volatile 





Three samples of pure whole allspice were more fully analyzed by 
Winton, Mitchell, and Ogden with the results given on page 4364 

The Tannin Equivalent in Allspice. — Tannin is present in allspice, 
though to a less extent than in cloves. The exact amount present is 
rarely determined, but rather the " oxygen equivalent," or quercitannic 
acid, as explained on page 429, the determination being carried out as 
there detailed. 



* U. S. Dept. of Agric, Div. of Chem., Bui. 13, p. 229. 
t An. Rep. Conn. Exp. Sta., 1898, pp. 178, 179. 
X Ibid., pp. 208, 209. 



436 



FOOD INSPECTION AND ANALYSIS. 





Moisture. 


Ash. 


Ether Extract. 


Alcohol 




Total. 


Soluble 
in Water. 


Insoluble 
in HCl. 


Volatile. 


Non- 
volatile. 


E.x tract. 


Maximum 


10.14 

9-45 
9.78 


4.76 
4-15 
4-47 


2.69 
2.29 
2.47 


0.06 

0.00 
0.03 


5-21 
3-38 
4-05 


7.72 
4-35 
5-84 


14.27 

7-39 
11.79 


Minimum 


Average 





Reducing 

Matters 
by Acid 
Conver- 
sion, as 
Starch. 



Starch 

. by 

Diastase. 



Crude 
P'iber. 



Nitrogen, 
X0.2S. 



Oxvgen 




Absorbed 


Querci- 


by Aque- 


tannic 


ous Ex- 


Acid. 


tract. 




1-59 


12.48 


1.03 


8.06 


1.24 


9.71 



Total 

Nitrogen. 



Maximum 
Minimum 
Average . . 



20.65 
16.56 
18.03 



3-76 
1.82 
3-04 



23-98 
20.46 
22.39 



6-37 
5-19 
5-75 



0.83 
0.92 



Microscopical Examination of Powdered Allspice. — By soaking the 
powder twenty-four hours or more in chloral hydrate, many of the harder 
portions are rendered much more transparent than would otherwise 
be possible. Fig. 83, after Moeller, shows the microscopical structure 
of various elements that go to make up allspice powder. 

The epidermis, or outer layer of the berry with its small cells, is shown 
in cross-section at (la) and in surface view at (2). Just beneath the 
outer coat are the large oil spaces (ih) and still further below the stone- 
cells (ic)- The fruit parenchyma (3) has vascular tissues running through 
it. (4) and (5) arc the inner epidermis and stone cells of the dividing 
partitions between the seeds. Small hairs connected with the outer 
epidermis arc shown at (6). (7) and (8) show in cross-section a portion 
of the seed-shell and inclosed seed or embryo, with the starch (8a) and 
the colored lumps of gum or resin (Sb) of a port- wine color. These colored 
cells exist in the seed coating, and, although only one is here shown, 
constitute a very important and striking characteristic of allspice. (9) 
represents the spongy parenchyma of the seed shell, and (10) shows its 
epidermis. In the parenchyma of the fruit and of the partitions between 
the cells arc seen, but not always plainly, minute crystals of calcium oxa- 
late (see (4) and (5)). 

These details so closely drawn by Moeller are idealized, but serve 
well to indicate what should be looked for. In practice the water- 
mounted specimen shows all the characteristics necessary to identify 
pure allspice, and most if not all its adulterants. In fact pimento is one 
of the easiest spices to identify under the microscope, by reason of its 
striking characteristics. 



SPICES. 



437 



Three distinctive features are especially typical, viz. : First, the starch 
grains, which are very uniform in size, measuring about 0.008 mm. in 
diameter, being nearly circular as a rule, and often arranged in groups 
not unlike masses of buckwheat starch. Ordinarily these masses con- 
tain fewer granules than do those of buckwheat. The granules are 




Fig. 83 — ^Powdered Allspice under the Microscope. X125. (After Moeller.) 



smaller and more inclined to the circular than to the polygonal form, 
while in many cases they have distinct central hila. The starch grains 
are very numerous and are found in nearly every field. Sec Fig. 195, PI. 
XIX. 

A second distinctive feature of allspice is the stone cells, of which there 
are many. These are more often colorless, and in most cases very large 
and plainly marked. They are sometimes seen singly and at other 
times grouped together. Frequently they are attached to pieces of brown 
parenchyma. 



438 FOOD INSPECTION AND ANALYSIS 

The third and most characteristic feature of allspice powder under 
the microscope is the striking appearance of the lumps of gum or resin, 
which are of a more or less deep port-wine or amber color and are con- 
tained in the middle layers of the seed coat. These cells are very striking, 
occurring sometimes in isolated bits, and in other cases in aggregations 
of from 2 to 4 or even 6 to 8 cells. These resinous lumps appear plainly 
in Fig. 194, PI. XIX. Droplets of oil are occasionally seen, but not in 
profusion. As a rule the oil is forced out of its large containing cells 
and into the surrounding tissue by the process of drying. 

U. S. Standards. — According to the U. S. standard for allspice, quer- 
citannic acid should not be less than 8%, total ash not more than 6%, 
ash insoluble in hydrochloric acid not more than 0.4%, crude fiber not 
more than 25%. 

Adulteration of Allspice. — The most common adulterants reported in 
powdered allspice are cocoanut shells and the cereal starches. Besides 
these the writer has found in Massachusetts, peas, pea hulls, exhausted 
ginger, cayenne, olive stones, pepper, and turmeric. To this list may 
be added clove stems, which are on record as a not uncommon adulterant 
in some localities. All of these are to be readily recognized by a care- 
ful microscopical examination. 



CASSIA AND CINNAMON. 

Nature and Composition. — The terms cassia and cinnamon are inter- 
changeable in commerce, though, strictly speaking, they represent two 
separate and distinct species of the genus Cinnamomum, belonging to 
the laurel family (JLauracecE). True cinnamon is the bark of Cinnamo- 
mum zeylanicum, a tree from 20 to 30 feet high, having horizontal or 
drooping branches, and native to the island of Ceylon, but cultivated 
also in some parts of tropical Asia, in Sumatra, and in Java. The entire 
yield of pure Ceylon cinnamon is extremely small, and but little of it 
is found in this country. It is the very thin, inner bark of the tree, and 
is of a pale, yellowish-brown color, being found on the market in long, 
cylindrical, quill-like rolls or pieces, the smaller rolls being inclosed in 
the larger. The outer surface is marked by round dark spots, corre- 
sponding to points of insertion of the leaves, and it is also furrowed length- 
wise by somewhat wa\'y, light-colored lines. The inner surface of the 
bark is darker colored, and has no lines. In thickness the bark varies 
from 1.5 to 3 mm. Both the inner and outer coatings of the bark of 
Ceylon cinnamon are usually removed in the process of preparation, so 



SPICES. 



439 



that it is of a much cleaner and more even texture than the cassia bark, which 
is thicker and heavier by reason of the outer cork layer usually left on it. 

The cheaper and more common cassia is the bark of the China- 
momum cassia, w^hich comes from China, Indo-China, and India. It is 
of a darker color than that of cinnamon, of coarser texture, and as 
a rule about four times as thick. Most varieties of cassia bark are less 
tightly rolled than cinnamon, and are not arranged one within the other 
in layers. The outer surface is marked by elHptical spots left by the 
leaves, and by small, dark-brown, wart-Hke protuberances. Cassia does 
not have the wavy, hght-colored lines found in the cinnamon. Both 
cinnamon and cassia barks are very aromatic in taste, somewhat astrin- 
gent, and slightly sweet. 

Cassia buds are the dry flower buds of China cassia, and are found 
m the market both in whole and in powdered form. Powdered cassia 
often consists of a mixture of several varieties of bark, while the cheaper 
grades sometimes contain an admixture of the ground buds. 

The best grade of cassia is that from Saigon, a much cheaper, from 
Batavia, while the cheapest is the China cassia. 

The odor of cassia and cinnamon bark is due to the volatile oil, of 
which from i to 2 per cent is usually found. Cassia and cinnamon oil 
greatly resemble each other, the principal constituent in either case being 
cinnamic aldehyde, CeH^CH: CH.CHO. Besides this, one or more esters 
of acetic acid are present. Both oils are very pungent and intensely sweet. 

Starch is present in cassia to the extent of from 16 to 30 per cent. 
A very small amount of tannin is found, as well as cinnamic acid and 
mucilaginous matters. Cassia buds are somewhat similar in com- 
position to the bark. They have, however, less starch and crude fiber, 
and higher contents of volatile oil and nitrogen than the bark. 

Richardson * has made analyses of a few samples of pure whole cinna- 
mon and cassia, from which the following are taken: 






fe 



^:2 






Ceylon cinnamon i 

Cassia bud'^ 

Cassia bark (4 samples) : 

Maximum 

Minimum 



5-40 
7-43 
4-79 

17-45 
9-32 



4-55 
3-40 
5-58 

8.23 
2.48 



1.05 

.82 

3-59 



3-51 

-55 



1.66 

1.58 
5-21 

2.38 
-74 



33-08 

25-63 
8.60 

26.29 
14-33 



3-80 
7.00 

4-55 
2-63 



51.28 
56.84 
65-23 

6^-33 
48.65 



.62 
1. 12 

•73 
.42 



* U. S. Dept. of Agric., Div. of Chem., Bui. 13, p. 221. 



440 



FOOD INSPECTION AND ANALYSIS. 



Winton, Ogden, and Mitchell's * results of analyses of whole samples 
of cinnamon, cassia, and cassia buds are thus summarized: 



Moisture. 



Ash. 



Total. 



Soluble 

in 
Water. 



Insoluble 
in HCl. 



Ether Extract. 



Volatile. 



Non- 
volatile. 



Ceylon cinnamon (6 samples) 

Maximum 

Minimum 

Average 

Cassia bark (20 samples): 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



10.48 

7-79 
8.63 



11.91 

6-53 
9.24 

7-93 



5-99 
4.16 
4.82 

6.20 
3.01 
4.73 

4-64 



2.71 
1.40 
1.87 

2.52 
0.71 



0.58 
0.02 
0.13 

2.42 
0.02 
0.56 

0.27 



1.62 
0.72 
1-39 

5-15 
0-93 
2.61 



1.68 
I-3S 
1-44 

4-13 
1.32 
2.12 

5-96 



Alcohol 
Extract. 



Reducing 

Matters 

by Acid 

Conversion, 

as Starch. 



Crude 
Fiber. 



Nitrogen, 
X6.2S. 



Total 
Nitrogen. 



Ceylon cinnamon (6 samples) : 

Maximum 

Minimum 

Average 

Cassia bark (20 samples): 

Maximum 

Minimum 

Average 

Cassia buds (2 samples): 

Average 



13.60 

9-97 
12.21 

16.74 

4.57 
8.29 



22.00 
16.65 
19.30 

32.04 
16.65 
23-32 

10.71 



38.48 

34-38 
36.20 

28.80 

17-03 
22.96 

13-35 



4.06 
3-25 
3-70 

5-44 

4-34 

7-53 



0.65 
0.52 
0-59 

0.87 

0-53 
0.69 



Structure of Powdered Cassia under the Microscope. — Fig. 84, 
from Moeller, shows various elements of cassia bark as veiwed microscop- 
ically, (i) shows in cross-section a portion of the cork and outer layer 
of the bark rind, with flat cells nearest the surface, having somewhat 
thick walls and reddish-brown contents, and, farther in, the cells s, with 
mucilaginous material. 

The stone cells of the intermediate layer of bark are shown at (2). 
Here the tendency of the stone cells is to be thicker on one side than on 
the other, as is plainly shown. (3) represents the structure of the inner 
layer of the bark, showing bast fibers b cut across, and more of the so- 
called mucilaginous cells 5 of large size, which normally contain the 
ethereal or volatile oil. The starch granules (4) are contained in great 
abundance in the polygonal cells of the parenchyma of the intermediate 



* Twenty-second Annual Report Conn. Exp. Sta., 1898, pp. 204, 205. 



SPICES. 



441 



and inner bark layers. (6) represents a fragment of a bast fiber, which 
is often shown in cassia powder with connecting parenchyma. The 
slone-cells cf the cork are shown in plan view at (7). Very small, needle- 
like crystals of oxalate of calcium are occasionally to be seen if looked for 
carefully. They occur in the parenchyma cells of the inner and inter- 
mediate layers of the bark. 

The microscopical structure of Ceylon cinnamon much resembles 
that of cassia. Cassia starch grains measure from 0.0132 to 0.0222 mm., 




Fig. 84.^— Powdered Cassia under the Microscope. X125. (After Moeller.) 



being considerably larger and more abundant that those of true cinnamon. 
As a rule the bast fibers of cassia are larger, but shorter, than those of 
cinnamon, and provided with thicker walls. 

Figs. 203 and 204, PL XXI, show various phases of pure cassia bark as 
photographed from water-mounted specimens of the powder. Cassia 
starch somewhat resembles that of allspice, but it is not as a rule found 
in masses containing as many granules as does the allspice starch. Very 
commonly two or three of the starch granules are arranged together in 



442 FOOD INSPECTION AND ANALYSIS. 

such a manner that at first sight they appear to form a single large granule, 
but on more careful examination are seen to be two- and three-lobed, 
consisting of several smaller grains. Stone cells, which are very abundant 
in the powdered cassia, do not happen to be included to any extent in 
the photographed fields. Cassia stone cells are generally more oblong 
than those of allspice, and are more often brown in color, while the all- 
spice stone cells are generally colorless. 

A distinctive feature of powdered cassia consists in the long-amber- 
colored wood fibers, some distributed in bundles, and others arranged 
singly. These are very clearly shown in Figs. 204 and 205. 

Yellow patches of cellular tissue with starch grains interspersed 
among them are very abundant in the powder. 

The U. S. Standards place limits as follows: Total ash not to exceed 
5%; sand not to exceed 2%. 

Adulteration of Cinnamon and Cassia. — The commonest adulterants 
are cereal products and foreign bark. Besides these, the writer has found, 
in samples sold in Massachusetts, leguminous starches, pea hulls, nut- 
shells, turmeric, pepper, olive stones, ginger, mustard, and sawdust. 
Much of the China cassia when imported contains an inexcusably large 
amount of dirt. In one sample Winton, Ogden, and Mitchell found 
over 15% of sand. 

Ground Bark of the Common Trees, especially that of the elm, 
resembles in physical appearance ground cassia, and is to be looked 
for as an adulterant. Fig. 265, PI. XXXVII, shows the appearance of 
ground elm bark. The fibers of cassia bark have starch granules as a 
rule interposed among them, while the foreign bark, usually of a much 
coarser texture, shows no starch connected with its structure. 

Fig. 206, PI. XXII, shows a water-mounted specimen of adulterated 
cassia powder, chosen from samples purchased in the Massachusetts 
market. Nothing but the adulterant (a foreign bark) shows in the field. 
The tissue is loose and considerably coarser than that of cassia bark. 

PEPPER. 

Nature and Composition. — Pepper is the dried berry of the pepper 
plant {Piper nigrum), a climbing shrub belonging to the family Pipe- 
racecB, native to the East Indies, but cultivated in many tropical countries. 
The height of the pepper plant is from twelve to twenty feet. When 
the fruit begins to turn red, it is gathered and then dried, by which process 
it turns black and shrivels up, forming the black peppercorns of com- 
merce. They are spherical single-seeded berries, about 5 mm. in diam- 



SPICES. 



443 



merce. They are spherical single-seeded berries, about 5 mm. in diam- 
eter, covered with a brownish-gray epicarp, and having on the under 
side the remains of a short stem. At the top of the berry is an indistinct 
trace of a style, and of a lobed stigma. 

Varieties of black pepper are named from the localities in which they 
are grown or from which they are shipped, as Singapore, Lampong, 
Sumatra, Tellicherry, Malabar, Acheen, Penang, Alleppi, Trang, Man- 
galore, etc. 

White pepper is obtained by decorticating the fully ripened black 
peppercorns, or removing the dark skin. This is accomplished by mac- 
erating them in water to loosen the skin, which is then removed readily 
by drying and rubbing between the hands. White whole pepper grains 
are grayish white, and a trifle larger than the black pepper berries. They 
are nearly spherical in shape, and have a number of light-colored lines 
that, like meridians, run from top to bottom. The common varieties 
are Siam, Singapore and Penang, the latter being coated with lime. 

The pungent taste of pepper is due in great part to its essential oil, 
a hydrocarbon of the formula CioHie, present in amounts varying from 
0.5 to 1.7 per cent. Pepper oil contains phellandrene and a terpene. 

Other important constituents of pepper are piperidine, and the crys- 
talline base piperin, C17H19NO3, insoluble in water, but soluble in ether, 
and in alcohol. Starch is present in pepper to a large extent. 

Burcker gives the following average percentage composition of black 
and white pepper: 



Black pepper . 
White pepper. 



4-57 12.45 
1.80 6.08 



12.50 
13-56 






1.36 
0.94 



6.85 
7. II 



$0. 



42.90 
56-04 



C 3 

o o 

2; C c^ 



^•sl 



7-39 

3-35 



Richardson's * analyses of three samples of whole black and two 
samples of whole white pepper, all pure, are as follows: 



Black pepper: West coast. 

Acheen. 

Singapore. , 

White pepper: West coast. 
Singapore . 



Water. 



8.91 
8.29 
9-83 
9-85 
10.60 



Ash. 



4.04 
4.70 

3-7° 
1. 41 

1-34 



Volatile 
Oil. 



.70 
1.69 
1.60 

-57 
1.26 



Piperin 

and 
Resin. 


Alcohol 
Extract. 


7-29 
7-72 
7-15 
7-24 
7-76 


6.06 

5-74 

2-57 



Starch 
(Acid Con- 
version) . 



36.52 
37-50 
37-30 
40.61 
43.10 



* U. S. Dept. of Agric, Bur. of Cham., Bui. 13, part 2, p. 206. 



444 



FOOD INSPECTION AND ANALYSIS. 



Undeter- 
mined. 



Crude 
Fiber. 



Albumin- 
oids. 



Total 

NX6.2S. 



Total N. 



Black pepper: West coast 
Acheen. . . 
Singapore . 

White pepper: West coast 
Singapore , 



24.62 

13-64 
17.66 
23.28 
19-55 



10.23 
10.02 
10.02 

7-r3 

4.20 



7.69 
10.38 

10.00 

9-31 

9.62 



9.«i 
12.60 
12.08 
11.48 
11.90 



1-57 
2.02 

1-93 
1-83 
1.90 



Richardson gives the following variations in the constituents of pure 
pepper: 





Black. 


V^hite. 


Water 


8.0 to II.O 

2.75 to 5.0 
.50 to 1.7s 
7.0 to 8.0 
32.0 to 38.0 

8.0 to II.O 

7.0 to 12.0 


8.0 to II.O 

1.0 to 2.0 
.50 to 1.75 
7.0 to 8.0 
40.0 to 44.0 
4. 1 1 to 8.0 
8.0 to 10. 


Ash 








Crude fiber 







McGill's * analyses of six samples of whole black, and five samples 
of whole white pepper, all genuine, are thus summarized: 





Moisture, 
etc., Lost 
at 100° C. 


Ash. 






Soluble 
in Hot 
Water. 


Insoluble 
in Water. 


Total. 


Insoluble 
in Hydro- 
chloric 
Acid. 


Sand 

Expressed 

as Per 

Cent of 
Total 
Ash. 


Alcohol 
Extract. 


Black: Maximum 

Minimum 

Mean 


14.10 
10.62 
12.03 
13.00 
11.30 
12.34 


2.64 
2.07 
2.41 
0.72 
0.14 
0.54 


3.06 
1.46 
2.05 
3-04 
1-50 
2.46 


5.16 
3-98 
4-47 
3-65 
1.64 
3.00 


1.08 
.06 
0.36 
0.88 
0.26 
0-55 


21 
2 
8 

42 

9 

21 


9.06 
8.28 
8.71 


White: Maximum 

Minimum 

Mean 


8.92 
7.00 
7-73 







Winton, Ogden, and Mitchell's, and Winton and Bailey's f analyses 
of whole black pepper and whole white pepper, rc] resenting the leading 
varieties imported into the United States, also of pepper shells and long 
pepper, are summarized in the following table: 

♦Canada Inl. Rev. Dept. Bui. 20, 1890. 

t An. Rep. Conn. Exp. Sta., 1898, pp. 198-199; 1903, pp. 158-164. 



SPICES. 



445 





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i46 



FOOD INSPECTION AND ANALYSIS."^ 



The following table summarizes the results of full analyses of pepper 
and pepper shells recently made by Doolittlc :* 





No. of 
Samples. 


No. of 
Varieties. 


Mois- 
ture. 


Ash. 


Starch by 
Diastase 
Method. 




Total. 


Insoluble 
in HCl. 


Soluble in 
Water. 


Black pepper: 

Maximum 

Minimum 


45 
25 

3 

4 


12 
9 


11.96 
8.09 
9-54 

13-34 
8.04 
9.87 

10.13 
8.43 

11. GI 

7.00 


8.04t 

3-43 

4-99 

4.28 
G.86 
1.69 

14.39 
6.12 

28.81 
7.82 


2-59t 

0.05 

0.58 

0.86 
0.05 
0.19 

5-92 
0.45 

22.90 
0.79 


5-32 
i-6s 
2.49 

1.16 
G.12 
0-34 

4-39 
1.72 

4.66 
1-53 


41-75 
25.09 
36.69 

63-55 
48-88 

54-37 

45-87 
28.43 

11.70 
9.28 


Average 


White pepper: 

Maximum 


Minimum 

Average 


Long pepper: 

Maximum, 


Minimum . .......... 


Pepper shells: 

Maximum 

Minimum 







Ether Extract. 


Crude 
Fiber. 


Nitrogen. 


Total N 




Volatile. 


Non-vola- 
tile. 


Total. 


In Non- 
volatile 
Ether 
Extract. 


non- vola- 
tile Ether 
Extract 
X6.2S. 


Black pepper: 

Maximum 


2.10 
0.85 
1.30 

1.66 
0.78 
1.17 

1. 01 
0.79 

1. 11 

G.89 


10.44 
6.60 
7.67 

7.26 
5-6^ 
6.46 

7-53 
5-71 

4.67 
1-51 


18.89 
10.05 
11.12 

7-65 
0.10 

4-17 

10.01 
7.19 

28.22 
21.06 


2.38 
1.86 
2.11 

2.14 
1.85 
1-97 

2.04 
2.13 

1.82 
1.72 


0-45 
0.25 


13.12 

9-25 


Minimum 


Average .............. 


White pepper: 

Maximum 


0.34 j 11.56 
0.24 9-69 
0.30 10.44 


Minimum 


Average ............... 


Long pepper: 

Maximum 


Minimum 


0.18 11.37 

0.12 ! 11.25 


Pepper shells: 

Maximum 


Minimum 









t Two samples of Acheeii C pepper had a total ash of S.00% and 8.04%, with "ash insoluble in 
HCl" jf 2.50% and 2.40% respectively. Eliminating these two samples, which were evidently 
abnormally^ high in sand and dirt, the highest total ash of the remaining 43 samples was 7.00%, 
while vhe highest ash insoluble in HCl was 1.80%. 

Determination of Nitrogen in Black and White Pepper. — Winton, 
Ogden, and Mitchell have shown that the Kjeldahl and Gunning methods 
are inapplicable in the case of pepper, owing to the presence of piperin, 
.bui that the Gunning- Arnold t method gives accurate results. In accord- 
ance with this method, i gram of the sample is mixed with a gram each of 
copper sulphate and red oxide of mercury, about i6 grams of potassium 



* Mich. Dairy and Food Comm. Bui. 94. 
t Zeits. anal. Chem., 31, 1892, p. 525. 



SPICES. 447 

sulphate, and 25 cc. of sulphuric acid in a Kjeldahl flask, for both diges- 
tion and distillation, of about 600-cc. capacity. The heating is conducted 
in the usual manner, beginning with a gentle heat till the frothing ceases, 
and gradually increasing the temperature till the mixture boils. The 
boiling is continued for three or four hours, after which the flask is 
cooled, and to it are added 300 cc of water, 50 cc. of potassium sulphide 
solution,* and enough of a saturated solution of sodium hydroxide to 
render the reaction alkaline. 

The flask is then connected to the condenser, and the distillation con- 
ducted as in the usual Gunning method, using zinc dust to prevent bump- 
ing, receiving the distillate into standard acid, and titrating against standard 
alkali. 

Nitrogen Determination in the Ether Extract.f— Ten grams of the 
sample are extracted with absolute ether for twenty hours in a con- 
tinuous-extraction apparatus, the extract being collected in a tared Kjel- 
dahl extraction- and distillation-flask, the same as used in the preceding 
section. The ether is then evaporated off, the residue dried to constant 
weight at 110° C. and its weight ascertained. The nitrogen is then 
determined in the ether extract by the Gunning- Arnold method. 

Determination of Piperin.J — Fifty grams of the sample are thoroughly 
exhausted with hot alcohol, and the alcohol extract evaporated to dry- 
ness. The dry residue is then treated with a solution of potassium 
hydroxide, and washed upon a filter. The residue is washed several 
times with the caustic alkali, which dissolves the resinous matters, and 
afterwards with water. It is then dissolved in alcohol, from which crystals 
of crude piperin separate on evaporation. These are redissolved in 
alcohol, and precipitated by the addition of water. The crystalline pre- 
cipitate is collected on a tared filter, washed with water, dried, and 
weighed. 

Piperin may be roughly estimated by multiplying the nitrogen in 
the ether extract by the factor 20.36. 

The amount of piperin varies considerably, ranging in black pepper 
from 4 to 9 per cent. * 

Microscopical Characteristics of Ground Pepper. — Moeller's repre- 
sentation of powdered black pepper shows what should be looked for 
under the microscope with the best conditions (Fig. 85). The sheU of 
the peppercorn, a cross-section of which is shown at (i), consists of the 

* Forty grams KjS in i liter or water. 

t Method of Winton, Ogden and Mitchell. 

J Villiers et Collin, Substances Alimentaires, p. 371. 



448 



FOOD INSPECTION AND ANALYSIS.] 




Fig. 85. — Powdered Black 
under the Microscope. 
(After Moeller.) 



Pepper 
X 125. 



epidermis, a, under which is a thin layer of brown parenchyma, c, 

while below this layer is shown the most characteristic portion of 

the pepper shell, viz.: the thickened, 
colored, stone cells, b. These are as a 
rule inclined to be rectangular rather 
than rounded. At d is shown a bit of 
the colorless parenchyma of the fruit 
itself. 

(2), (3), and (4) show a cross-section 
of the outer part of the berry, (2) 
representing the inner stone-cell layer, 
a single row of horseshoe-like cells, 
(3) the thin seed coat, and (4) the white 
perisperm, with its large cells. Here and 
there through the perisperm certain yellow 
contents are visible, consisting largely of 
resinous matter. A dark resin cell is 
shown at (4). The ethereal oil, starch, 
and piperin are found in this part of 
the berry. 
(5) shows in surface view the mostly rectangular stone cells of the 

pepper shell, resting upon the epidermis (6). Groups of stone cells 

are frequently thus found with portions of the epidermis. 

The inner rounded, or cup-shaped cells are shown in plan view at 

(7) and the seed skin at (8), masses of starch and separate starch granules 

are shown at (9), and crystals of piperin at (10). 

The bast -parenchyma of the pepper stem is shown at (11), 

pieces of which are commonly found in powdered pepper, and (12) 

shows a fragment of one of the many-celled hairs which grow on the 

stem. 

The rounded cup cells (7) are readily distinguished from the more 

rectangular stone cells (5). The walls of the cup cells are nearly always 

colorless, and the cells themselves empty.* 

A water-mounted specimen of finely ground, black pepper, when 

viewed microscopically, shows most of the elements above described, at 

least in fragmentary form, though, in the case of the coarser particles, 

* The harder portions of the pepper, especially of the shell, are best examined by soak- 
ing for at least twenty-four hours in chloral hydrate, and mounting in this reagent on the 
slide. 



SPICES 449 

by no means as clearly as by the use of chloral hydrate. Large polyg- 
onal masses of starch appear grouped as photographed in Fig. 256, PI. 
XXXIV, if not rubbed out too fine under the cover-glass. Starch, in- 
deed, is the most conspicuous element of pepper, being distributed more 
or less evenly throughout the mass. The powder may, however, be so 
finely reduced by abrasion under the cover-glass as to break up these 
starch masses wholly or in part, so that the granules may appear in much 
smaller groups or even singly. Fig. 255 shows such a field under a 
higher magnification. The individual granules of pepper starch average 
0.003 ^^- i^ diameter. 

Besides the starch, and next to it the most numerous, one finds in the 
water-mounted black-pepper specimen many of the dark-yellow, thick- 
walled stone cells, patches of the colored parenchyma, and epidermis of 
the shell. Other elements of the perisperm, besides the starch, are 
seen in fragments, such as bits of resin, small droplets of oil, pieces of 
stems, and occasionally the needle-shaped crystals of piperin. Some 
of the rounded, cup-shaped cells are also usually found. 

White pepper contains, of course, the same elements, but without 
the deeply colored stone cells and other characteristics of the shell, 
which has been removed from it. 

U. S. Standards for Pepper. — The following limits of constituents 
have been adopted: For white pepper, non- volatile ether extract should 
not be less than 7%; starch should not be less than 52^; total ash 
should not be more than 3.5%; ash insoluble in hydrochloric acid should 
not exceed 0.3%; crude fiber should not exceed 5%. For black pepper, 
non-volatile ether extract should not be less than 6.75%; starch should 
not be less than 30%; total ash should not exceed 7%; ash insoluble in 
hydrochloric acid should not exceed 1.5%. 

Adulterants of Pepper. — Pepper shells obtained in preparing white 
pepper, are not infrequently ground and added to the cheaper grades 
of black pepper. When a sample of black pepper is shown by the micro- 
scope to contain more shells in proportion to the other elements than 
could be possible in a ground whole berry, added shells are indicated. 
The analyst should, for comparison, grind in a mortar single berries of 
various giades, and familiarize himself with the appearance of the ground 
powder under the microscope, when the maximum amount of shells pos- 
sible under natural conditions are present, noting especially the appar- 
ent number of stone cells of the outer coating. The familiar title of P. D. 
(pepper dust) originally given to ground pepper shells, stems, and " sweep- 



450j FOOD INSPECTION AND ANALYSIS. 

ings " is now applied in the trade not only to almost any cheap and appro- 
priate material for admixture with pepper, but also, in a broader sense, 
to ground powder suitable as an adulterant for any spice. 

The presence of pepper shells is indicated by an excess of ash, sand, 
and crude fiber, and a deficiency of starch. 

Hilger and Bauer, also Hanus and Bien, advocate the determination 
of pentosans as a means of detecting pepper shells. 

Ground Olive-stones constitute one of the most commonly found foreign 
materials used as an adulterant of pepper. The powder, sometimes 
called " poivrette," is very like white pepper in appearance, is whojly 
inert in taste, and thus forms an admirable adulterant. While best 
detected by their characteristic appearance under the microscope, their 
presence may be shown by various color tests, although these do not 
differentiate olive stones from nutshells and similar woody materials. 

Pabst has adopted for this purpose a test first suggested by Wurster 
for the detection of wood pulp in paper. The reagent is prepared as 
follows: In a porcelain capsule lo grams of commercial dimethyl anilin 
are mixed with 20 grams of pure concentrated hydrochloric acid, and 
at least 100 grams of cracked ice are added. Then, while stirring, a 
solution of 8 grams of nitrite of soda in 100 cc. of water are added little by 
little, and the mixture allowed to remain for half an hour, after which 
30 or 40 cc. of hydrochloric acid are added , and 20 grams of lin-foil. 
The reduction is allowed to go on for half an hour, heating on the water- 
bath, if necessary. The tin is then precipitated by granulated zinc, the 
liquid is filtered, and the filtrate neutralized with carbonate of potassium 
or sodium to the point of forming a precipitate, the precipitate being 
dissolved by a few drops of acetic acid. Finally the volume is made up 
with water to 2 liters, adding, before doing so, 3 or 4 cc. of a concentrated 
solution of sodium bisulphite, to prevent oxidation. The reagent thus 
prepared will keep for several years in a brown, tightly stoppered bottle. 

If a pinch of pepper, which contains ground olive stones, be heated 
gently with a little of the above reagent in a test-tube, the stone cells 
of the adulterant will be colored a bright red brown, and the colored 
particles will be seen to settle to the bottom of the tube, after shaking, 
more quickly than the rest of the powder. Or, if the whole is poured 
from the test-tube into a porcelain dish,. the color is more marked. Pure 
pepper is not colored under this treatment with the reagent. 

Jumeau uses for a color reagent 5 grams of iodine in 100 cc. of a mix- 
ture of equal parts of ether and alcohol. Enough of the finely ground 
pepper to be examined is placed in a porcelain capsule to cover the 



"spices. 461 

bottomof the dish, and sufficient iodine reagent is added to wet the entire 
mass, carefully avoiding excess. The thick paste is first mixed till homo- 
geneous, and then allowed to dry in the air, after which it is broken up 
by a pestle, and the powder examined, either under the microscope, or 
by the naked eye. With pure pepper, a more or less deep-brown color 
is produced uniformly through the powder, but if olive stones are present, 
particles of these are colored yellow. With the naked eye as small an 
admixture as 2% of olive stones can thus be detected. 

A solution of anilin acetate colors olive stones yelloviish brown, 
while pure pepper appears grayish, or white. 

Under the microscope olive stones are readily apparent, since the 
stone cells differ in size, form, and mode of grouping from those of pepper. 
Fig. 263, PI. XXXVI, is a photograph of a water- mounted specimen of 
olive stones. They are for the most part entirely devoid of color, being 
long and narrow. In shape and manner of grouping they much resemble 
cocoanut shells (p. 433), but are distinguished from the latter from their 
lack of color. 

Fig. 261 shows under low magnification a sample of pepper, bought 
on the market in Massachusetts, highly adulterated with olive stones. 
A large mass of the stone cells of the adulterant appears in the center of 
the field. Many of the stone cells are shown arranged end to end, so 
that what at first sight appear to be single, very long cells are in reality 
made up of several shorter ones. In ground oHve stones one frequently 
finds, besides the stone cells, bits of the outer tegument of the seed, show- 
ing large cells with sinuous, rather thick walls; also bits of parenchyma, 
crossed frequently by fibro-vascular duct bundles. 

Buckwheat Products. — Both the hulls and the middlings have been 
added to black pepper, and the middlings to white pepper. The starch 
of buckwheat possesses the added advantage, from the point of view 
of the spice-grinder, that it somewhat resembles pepper starch in micro- 
scopical appearance, not only in the shape of the starch granules, but also 
in the manner of grouping into masses. Compare Figs. 128 and 129, 
Plates II and III, showing buckwheat starch, with Figs. 255 and 256, 
PI. XXXIV, respectively, showing pepper starch made under similar 
conditions of magnification, etc. The starch granules and masses are 
coarser in the case of buckwheat than of pepper. 

Fig. 260, PI. XXXV, shows a photograph of a pepper sample adulterated 
with buckwheat, masses of both starches appearing in the same field. 

Other Adulterants found in Massachusetts samples of pepper have 
been wheat and corn products, nutshells, cayenne, charcoal, turmeric, rice, 



452 



FOOD INSPECTION AND ANALYSIS. 



sand, and sawdust. Charred cocoanut shells were at one time extensively 

use J (see pp. 433 ^^^ 434)- 

Long Pepper, according to English analysts, has been used to a con- 
siderable extent as an adulterant. This is the fruit of the Piper longiim 
and P. officimrum, both oriental species. The fruit, as its name implies, 
is long and cylindrical, while of about the same diameter as the spherical 
true peppercorns. Long pepper contains, as a rule, less than half the 
amount of piperin that true pepper does, and rather more starch than 
bhck pepper. Its taste is much less pungent than that of true pepper. 

From its method of growth, long pepper is found with considerable 
dirt and sand adhering to the outer surface of the dried grains. This 
is due to the fact that the fruit often trails on the ground, and in gather- 
ing it the natives are not particular about removing the adhering soil. 
The surface of the fruit grains being very rough and irregular, much 
of the dirt remains dried thereon. The presence of long pepper thus 
materially increases the ash. 

Long pepper possesses a very disagreeable, but peculiar odor, devel- 
oped more especially when slightly warmed. For this reason, if for 
no other, it is not an ideal adulterant, since pepper containing it would 
not be palatable with warm food. At the present time it costs more than 
black pepper, and is used chiefly in mixed whole spices for pickles. 

Brown gives the following analyses of samples of long pepper: 



Total 
Ash. 



8.91 
8.98 
9.61 



Sand and 
Ash Insol- 
uble in 
Hydrochlo- 
ric Acid. 



1-5 



Starch and 
Matters 
Converti- 
ble into 
Sugar. 



44.04 

49-34 
44.61 



Albumin 

ous Matter 

Soluble in 

AlkaH. 



15-47 
17.42 

15-51 



Cellulose. 



15-7 
10.5 

10-37 



Alcoholic 
Extract. 



7-7 

7-6 

10-5 



Ether 
Extract. 



5-5 
4-9 
8.6 



Total 
Nitrogen. 



2-3 



According to Brown and Heisch, the granules of long pepper starch 
under the microscope are larger than those of true pepper, and more 
angular. Stokes,* however, finds no such marked difiference in the size 
of starch granules and his experience is shared by the writer. When 
the two specimens (long and true pepper) are viewed side by side in 
water mounts under the microscope, the average size of the long pepper- 
starch grains is a trifle larger than those of true pepper, though, unless 
compared directly, the difference is not readily apparent. Stokes sug- 
gests a method of distinguishing the two by polarized light. With crossed 



* Analyst 13, p. 109. 



SPICES. 453 

Nicols, so that a dark field is given, and with the specimen mounted 
in glycerin, true pepper starch shows an evenly dark appearance, using 
a low power, while with long pepper a " ghostly white " image is shown. 
Long pepper, when present in true pepper powder, may generally be 
rendered apparent by the development of the characteristic odor on 
heating. Bits of fluffy fiber from the catkin of the long pepper will 
always be found in the ground powder, and will be apparent under the 
magnifying-glass. 

Microscopic examination of the crude fiber discloses the highly char- 
acteristic, large, beaded cells of the endocarp, also elements of the spindle. 

RED PEPPER. 

Nature and Varieties. — According to the U. S. Standards red pepper 
is the red, dried, ripe fruit of any species of Capsicum, a genus of the 
nightshade family {SolanacecB) , indigenous to the American tropics, but 
now cultivated in nearly all warm and temperate countries, and is of 
two distinct kinds: cayenne pepper or cayenne, the dried ripe fruit of 
C.frutescens, C. haccatum, or some other small fruited species of Capsicum, 
and paprika, the dried ripe fruit of C. annuum, or some other large-fruited 
species of the genus, excluding seeds and stems. 

Boyles * states that in the trade, the larger podded varieties are usually 
called capsicums and the smaller, chillies, the term cayenne being applied 
only to the ground product made from either or both capsicum and chillies. 

Chillies are characterized by their extreme pungency and the small 
size of the pods, which seldom exceed 2 cm. in length. The leading 
commercial varieties come from Africa and Japan, the latter being the 
more brilliant in color. Zanzibar chillies, formerly the leading African 
variety, have given place in the market to Mombassa. 

Capsicums formerly denoted low grade peppers of a brown color with 
pods 2 to 3 cm. in length, or even longer, produced in Africa, especially 
in the vicinity of the river Niger, also in Japan, Korea, and India, but 
now is used in a broader sense as noted above. 

Paprika is a variety of C. annuum grown in Hungary. The powder 
is of a deep red color and has a sweetish, mildly pungent flavor. 

Tolman and Mitchell f state that of the five grades of ground Hun- 
garian paprika, named by Csonka and Varadi,| only three enter the 

* Jour. Ind. End. Chem., 9, 1917, p. 301. 

t Ibid., 5, 1913, p. 747. 

t Der Szegeder Paprika und der Szegeder Paprikahandel, 1907. 



454 FOOD INSPECTION AND ANALYSIS. 

United States: Rosen paprika, prepared from selected pods with removal of 
placentae, stalks, and stems, Konigs paprika, ground whole with the stems, 
and Merkanlil paprika, produced from spotted pods separated from better 
grades without removing stalks, stems, and other waste. 

Pimiento is a large-fruited pepper, a variety of C. annuum, grown in 
Spain. This has come to be known as Spanish paprika, which leads to 
its sale under the simple name paprika, thus eliminating the distinction 
from true paprika. The succulent pericarp is much used for stuffing 
olives, while the dried pod is ground as a spice, often being substituted 
for the more valuable Hungarian varieties. Its coloring properties are 
more pronounced than its flavor. 

The kitchen garden peppers, of which over thirty varieties are cul- 
tivated in the United States, also belong to the species C. annuum. 

The species of Capsicum have solitary flowers, with a five-cleft corolla, 
and the fruit is of an elongated, conical form. The surface of the fresh 
fruit is smooth and bright red or yellow, but it loses in brilliancy on dry- 
ing, and becomes shriveled. The pericarp is thin and tough, and at its 
base is a five-lobed calyx, greenish brown in color, terminating in a thick 
stem. The fruit proper is divided into two or three cells, which are 
separate and distinct at the lower portion, but which unite and form one 
at the top. The cells inclose a large number of yellow, wrinkled, kidney- 
shaped seeds, containing a fleshly endosperm, and a curved embryo. 

Constituents. — Red peppers contain a fixed, bland oil, found in both 
pod and seed, but more abundantly in the latter, considerable resinous 
and mucilaginous material, a red coloring matter confined to the pod, and 
the active principle capsaicin, a crystalline alkaloid, to which much of the 
pungency is due. 

Capsaicin is present in both seeds and pods, but is more abundant 
in the latter, particularly in the placentae, being dissolved in the oil. Thresh* 
first obtained the substance in an impure form, but Micko t prepared 
the pure substance and determined its formlua, C18H28NO3. According 
to Micko it forms white glistening plates, very soluble in alcohol, ether, 
chloroform, and benzol, less soluble in petroleum ether, difficultly soluble 
in hot, and insoluble in cold water; it is a weakly acid phenol-like sub- 
stance with an intensely biting taste, a drop of a weak alkaline solution 
containing only 0.00005 mg. when placed on the tongue giving a burning 



* Pharm. Jour. Trans., Nos. 315, 337, 376; Jahrb. Pharmakog., 1877. 
t Zeits Unters. Nahr. Genussm., i, 1898, p. 818. 



SPICES. 



455 



sensation lasting some time. Nelson * has corroborated Micko's findings 
and developed a test for capsaicin. 

The Red Coloring Matter is soluble in ether, petroleum ether, carbon 
bisulphide, and chloroform, but sparingly soluble in alcohol. 

Composition of Red Pepper.— Winton, Ogden, and Mitchell f analyzed 
eight samples of whole chillies, representing three varieties, namely Zan- 
zibar, Japan, and Bombay, the summarized results being as follows: 





Moisture. 


Ash. 


Ether Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl. 


Volatile. 


Non-vola- 
tile. 


Maximum 


7.08 
367 
5-73 


5 96 
5-o8 
5-43 


4-93 
3 30 
398 


0. 23 
0.05 
015 


2.57 
0.73 
1-35 


21 8r 


Minimum 


17.17 
20.15 


Average 





Maximum 
Minimum 
Average . . 



Alcohol 
Extract. 



27.61 
21.52 
24 -35 



Reducing 

Matters as 
starch, 

Acid Con- 
version. 



9 31 
715 
8.47 



Starch by 
Diastase 
Method. 



1.46 
0.80 



Crude 
Fiber. 



24.91 
20.3s 
22.35 



Nitrogen, 
X6.2S. 



14 63 
13 31 
1367 



Total 
Nitrogen. 



2.34 
2.13 
2.18 



The percentages of " starch by the diastase method " given in the 
above table represent errors of the process as neither cayenne nor paprika 
contain an appreciable amount of starch. 

Doolittle and Ogden| have made exhaustive analyses of known samples 
of Hungarian and Spanish red pepper, including determinations of non- 
volatile ether extract, and iodine number of this extract, which are of 
especial value in detecting added oil. A summary of their results is given 
on page 456. 

Tolman and Mitchell § have analyzed samples of whole chillies, paprika, 
and pimiento obtained through official channels with [results given on 
p. 457. They found that by sifting the total ash of African and Japan 
chillies could be lowered to a maximum of 6.16% and 5.82% and the 
sand to 0.85% and 0.53% respectively. In their examination of paprika 



* Jour. Ind. Eng. Chem., 2, 1910, p. 419. 
t Ann. Rep. Conn. Exp. Sta., 1898, pp. 200-201. 
t Jour. Am. Chem. Soc, 30, 1908, p. 1481. 
§ Loc. cit. 



456 



FOOD INSPECTION AND ANALYSIS. 







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NO'^tO'^'^-4- ni^OOnoO 


On m O 1 


p 






tH MM 




C) M (N M M 


M 




y, 














< 






to t^ to 00 oc 


on 


0'*00mio OtoO to nC 


H 


00 On 


.C 


•sn^^PA 


N M 00 M M 


M 


MTfoO'^toON OnOniomioOn •*« 1 


Pi 


w 




M O M M 


M 


mOOmOO mQmWm 


M 


O 


3 

< 


«4-l 




O J^ rt- 





OtoroOOto OOmOO 


rO NO O 







NO O O t^ M 


On MOOtoONt^ro OQtot^OOC 


ro 'to 


^* 


-aa^B^ 


m Tt Tt to •^ 


Tf NO -^ to NO to NO ro M c^ ro M 


M 


00 M 


Ph^ 


















N to O O 


O 


OONQtoto OOtoOO 


r^ t-- 


Ci^ 


^ 


•l^^ox 


O CI O On M 





nOOnOnO\no-* OO'^oO'^Onm 


M 


w 


<; 




00 NO t^ f>.NO 


t^ OOtONOOOt^OO NOrO'^rtro'* •*■<*■ | 


Ph 














M M 


Ph 






NtoONQi^to oOfOtootoM ONtor^MTj-NO 


Tj-NO 




'lOH 


N O M O c 


c 


000<N0m OOOmC 


C 


t M 


l-tH 




m sjqnjosuj 


O O O O 





oooooo ooooo 





o o 


P 




























w 






OOI-^NOnOnOn Of^'toOON NNioirtror^ nOOn I 


fV| 


•S 


•ja^BjVi 


NO NO M t^ to M 


MoO'^NOt^N t^t^oomcN 


rO rO 


W 


< 


u; aiqniog 


to'ttoiO'^to NO'S- lONO tONO fi M M Tt P 


rO 00 CO 


C/J 












1 








NO rooO On ■* P 


OOfOOOrOJ^ rONOOOM 




N o 


^ 




•F?ox 


O NO M J^ M 


o 


ONtoONONM OnOOnN'*'* roio 






t~- 10\0 NO lONO 


NOtONOt^NOt^ TtfOrotocOTf MIO 


Mh 














M M 


W 


















On NO Tl- 00 00 


ro NOtot^lONOON NOOOOOON-<t tOfO 1 


w 


•Q oOoi ^B ssoq 


fO ^ to to 01 


^ OO-^rorOMNO TfOOCtOM 


t^ to t^ 


^ 




On t^ 00 00 OC 


00 


OONOONOt^ NOiotoNQtoto NO-* i 


-rf 








M MM 






< 


•saiduiBg jo jaqiun^ 


^ M 




t^ (NT) i~» ro 




t^ <N 


Pi 
< 


























































o 














































^ 
















^3 






























;::) 
















1) 






























w 
















8 






























fe 
















1) 






























o 
















in 






























m 
















E 






























W 
















0) 






























(/) 
















in 






























;^ 
















T3 






























< 
< 




% 6 








See 








% e 
















~ D lU -■ 


a 


llV^ii 


a 


^ 3 IJ J 

.. E P SP E E 


0. 










ds: 

ian: Maj 
Min 
Ave 

: Maxim 


b 
t 

% 
< 


ds, place 

ian: Ma: 

Min 

Ave 

: Maxim 

Minim 

Ave rag 

Placent 

ian: Ma: 

Min 

Ave 

: Maxim 


a; 
I- 

4 


fe bC 

> a 

< fe 
^ > 






OH -G 




lu b X. -Ob -c 




I- -C 






hole P 
Hunga 

Spanis 




oj rt \fi c cu ^ 












ds (S 
Hung 

Spani 

eds a 
Hung 

Spani 












1^ 












Cu 
























rn 




1 



SPICES. 



and pimiento they determined the percentage of the different part 
follows: 



457 

;s as 





Paprika (21 Samples). 


Pimiento (18 Samples). 




Shells. 


Seeds and 
Placentae. 


Stems. 


Shells. 


Seeds and 
Placentae. 


Stems. 


Maximum 


63.7 
50.5 
56.4 


43-2 
28.1 
36.1 


9-4 
6.0 

7-5 


58.1 
531 
55-3 


37-4 
34-9 
36.0 


10.9 
6 


Minimum 


Average 


8.7 





Analyses were reported of each of the above separately as well as of 
the whole product and of the whole product less the stems as follows: 

COMPOSITION OF RED PEPPER (TOLMAN AND MITCHELL). 











Ash 




Ether Extract 


Non-vol. Ether Ext. 






*M W 


d 

6 








(Cont 


Ext.). 


(Shaking Method). 















ji 






d 






















c 

•5 








Xi to 

3< 


1^ a 





c 


u 

•d 
c 






> 

c 












2 


J 


H 


w 


> 


Z 


eu 




oi 


fe 


Mombassa Chillies 


26 






















Maximum 






8.41 


3.03 


6.41 


1.72 


19.00 








28.70 


Minimum 






S 34 


0.44 


4-73 


0.28 


15.88 








24.98 


Average 






6 31 


1.24 


5 07 


0.81 


17 26 








26.86 


Japan Chillies. . . . 


17 






















Maximum 






6. 20 


1.07 


5-50 


I 59 


23 21 








25.96 


Minimum 






5-08 


0.31 


4-52 


0.09 


17.10 








22.82 


Average 






5. 52 


0.53 


4.99 


0.56 


19.94 








24.25 


Cherry Chillies . . 


I 




6.62 


1.23 


5-39 


1. 18 


16.17 








26.20 


Hungarian Papriks 


i 






















With stems . . . 


7 






















Maximum. . . 




3.76 


6.03 


0.33 


5-73 


0.89 


16.43 


15.00 


134-0 


1.4854 


22.76 


Minimum . . . 




3 29 


5.08 


0.24 


4.82 


0.08 


12.21 


10.86 


129 8 


1-4758 


20.69 


Average 




3-47 


S 63 


0.28 


5. 36 


0.42 


14.04 


12.61 


132-6 


I .4806 


21.93 


Without stems. 


7 






















Maximum. . . 




4. 16 


5.56 


0.31 


5.2s 


0.90 


17-35 


15.08 


133.2 


1-4834 


23.18 


Minimum . . . 




3. II 


4.66 


0.20 


4.41 


0.07 


13-94 


12.64 


129.0 


I -4756 


20.47 


Average 




3 SI 


5.22 


0.26 


4.96 


0.34 


15-28 


13.91 


131-9 


1-4799 


21.56 


Spanish Pimiento: 
























With stems. . . . 


7 






















Maximum . . . 




S.98 


7.86 


0.48 


7.54 


0.69 


12.58 


10.81 


137.3 


I. 4818 


20.59 


Minimum . . 




4 31 


6.98 


29 


6.69 


0. 10 


11.30 


9.81 


136.0 


1-4776 


19.53 


Average 




5 06 


7-39 


35 


7.04 


0.47 


11.87 


10.34 


136.7 


I -4805 


20.13 


Without stems. 


8 






















Maximum . . . 




5-09 


7 35 


0.40 


6.98 


0.60 


13.34 


11.30 


137.2 


I. 4810 


20.34 


Minimum. . . 




452 


6.60 


0.24 


6.26 


0.2s 


11.58 


9.80 


134-5 


1.4792 


18.76 


Average 




4-83 


6.98 


0.32 


6.66 


0.44 


12.47 


10.67 


136 -I 


I. 4801 


19.49 



Boyles' * analyses of red peppers appear in the following table. South 
Carolina capsicums were grown under the indirect supervision of the Bureau 
of Plant Industry from Hungarian paprika seed, but in that climate be- 



* Loc. cit. 



458 



FOOD INSPECTION AND ANALYSIS. 



came so hot as to be classed, when ground, with cayenne. He believes 
that the United States standards for cayenne should be revised as follows: 
Total ash increased to 7.5%, ash insoluble in 10% hydrochloric acid 
(sand) to 1.0%, fiber to 20%, and non-volatile ether extract lowered 
to 14%. 

COMPOSITION OF RED PEPPER (BOYLES). 



Number of 
Analyses. 



Mombassa Chillies. . 

Maximum 

Minimum 

Average 

Japan Chillies 

So. Carolina Capsi- 
cums 

Maximum 

Minimum 

Average 

Bombay Capsicums 

Maximum 

Minimum 

Average 

Japan Capsicums. . . 

Maximum 

Minimum 

Average 

Korean Capsicums. . 

Maximum 

Minimum 

Average 

Niger Capsicums . . . 

Maximum 

Minimum 

Average 

African Capsicums. . 
Bombay Cherries. . . 

Maximum 

Minimum 

Average 



Ash. 



17 



35 



19 



Total. 



9 


40 


4 


36 


6 


08 


4 


63 



7- 


75 


4- 


82 


5- 


98 


9 


35 


5 


56 


6 


95 


6 


84 


4 


90 


6 


05 


7 


70 


6 


20 


6 


94 


6 


17 


S 


27 


5 


72 


5 


05 


5 


.67 


5 


■35 


5 


•51 



Insol. in 
HCl (Sand). 



1.77 

0-3S 
I .06 
0.18 



0.25 
0.78 

1-75 
o. 14 
0.76 

1.17 
o. 14 

0.39 
0.75 

0. 20 
0-5I 

1 . 27 
0.60 
0.83 
0.95 

0.82 
0.65 
0.74 



Ether Extract. 



Volatile.* 



(3) 
0.32 

0.15 
0.23 



I. 85 
0.15 
0.60 

(7) 
o. 72 
0.25 
0.45 

(3) 
0.40 
0.30 
0.35 

(2) 
0.60 
0.45 
0.53 

(2) 
0.85 
0.25 
O.S5 

(i) 
0.30 
0.30 
0.30 



Non-vol."* 



(6) 
25-49 
1575 
20.06 
22.50 



15-70 
10.75 
13.92 
(12) 
20.40 
12.35 
16.57 

(5) 
17.03 
12.80 
15-56 

(2) 
22.25 
19.77 
21.01 

21.96 
18.22 
19-53 
19-45 

17-55 
15.60 

16.57 



Fiber.* 



(6) 

30.45 
22.63 
26.25 
24.02 



30.48 
20.07 
25.48 

(8) 
32.30 
25.00 
28.08 

(5) 
26.64 
22.50 
23.84 

(2) 
26.02 
25-85 
25-94 

27.77 
22.82 

24-93 
28.76 

29. 20 
27-45 
28.33 



* Figures in parentheses are number of samples. 



Microscopical Structure of Red Pepper.— Fig. 86, from Moeller, 
shows the appearance under the microscope of various elements of powdered 
red pepper, (i) is a sectional view through the outer portion of the fruit 



SPICES. 



459 



shell or pod, showing the epidermis (a), and beneath this the collenchyma 
layer. The inner epidermis is shown at (2) with its cells thick-walled 
in places and inclosing brilliant, red oil drops of coloring matter, (3) 
represents the outer and (4) and (5) the inner epidermis in surface view. 
The outer epidermis of cayenne, which is the element of chief value in 
distinguishing this from paprika, is shown at (6). 




Fig. 86. — Powdered Red Pepper under the Microscope. Xi2s. (After Moeller.) 

A cross-section through the seed shell is shown at (7); a being the 
epidermis of the seed, b the parenchyma layer directly beneath, and c 
the tissues of the endosperm. (8) shows in surface view the peculiar 
seed epidermis, the appearance of which Moeller compares with that 
of intestines. At (9) is shown one of the isolated cells of this epidermis 
more highly magnified, while (10) shows the epidermis of the calyx. 

Figs. 211 and 212, PI. XXIII, show photomicrographs of powdered 
cayenne. In Fig. 211 is shown a large bit of the outer epidermis of the 
fruit pod, while in Fig. 212 appears a smaller portion of this same kind 



460 FOOD INSPECTION AND ANALYSIS. 

of epidermis, and next to this the characteristic skin of the seed shell, 
with its striking markings suggestive of the convolutions of the intestines. 
Yellow or yellowish-red droplets of oily coloring matter are distributed 
through the field. Starch grains are absent. 

U. S. Standards. — Cayenne: Non-volatile ether extract, not less than 
15%; total ash, not more than 7%; ash insoluble in hydrochloric acid, 
not more than 1%; starch, not more than 1.5%; and crude fiber, not 
more than 28%. 

Paprika: Total ash, not more than 8.5%; ash insoluble in hydro- 
chloric acid not more than 1%; iodine number of extracted oil, between 
125 and 136. Rosenpaprika : Non- volatile ether extract, not more than 
18%; total ash not more than 6%; ash insoluble in hydrochloric acid, 
not more than 0.4%; crude fiber, not more than 23%. Konigspaprika : 
same as rosenpaprika in limits, except that for total ash is 6.5%, and 
for ash insoluble in hydrochloric acid is 0.5%. Pimiento: non- volatile 
ether extract, not more than 18%; total ash, not more than 8.5%; ash 
insoluble in hydrochloric acid, not more than 1%; crude fiber, not more 
than 21%. 

The most common adulterants ot cayenne are the starches of the 
cereal grain?, corn and wheat. Ground pilot bread and crackers are 
especially common. Besides these the writer has found in the routine 
examination of cayenne samples in Massachusetts, ginger, nutshells, 
turmeric, rice, gypsum, buckwheat, olive stones, mustard hulls, ground 
redwood, red ocher, and coal-tar dyes. Fig. 213, PI. XXIV, shows a 
sample adulterated with wheat, corn, and cocoanut shells. 

Mineral Adulterants, such as gypsum, ^nd red ocher and other pigments, 
are all to be looked for in the ash by methods of qualitative analysis. 
An abnormally high ash is suggestive of adulteration. According to 
Vedrodi, the ash of genuine cayenne should not exceed 5.96. The presence 
of red ocher is rendered apparent by the high content of iron. 

Salts of lead and mercury are rarely if ever now used for color. 

Ground Redwood. — Numerous varieties of redwood are commonly 
used to intensify the color of cayenne, especially when otherwise highly 
adulterated with colorless materials, such as the starches. The redwood 
is sometimes used alone, and sometimes in mixture with turmeric. Both 
redwood and turmeric are readily recognized under the microscope. 

Fig. 214, PI. XXIV, shows a cayenne sample adulterated with corn 
starch and red sandalwood, a mass of the latter filling the center of the 
field. The wood fibers of the dyestuff, even when finely ground, are 
very striking under the microscope, showing a brick-red color. 



SPICES, 461 

Detection of Coal-tar and Vegetable Colors.— Oil-soluble coal-tar 
and vegetable colors may be tested for in cayenne and paprika by an 
adaptation of Martin's butter-color method, shaking the ether extract 
of the sample with the alcohol and carbon bisulphide mixture, page 557. 
The carbon bisulphide dissolves the oil and natural color, while the over- 
lying alcohol layer holds in solution many of the artificial coloring matters 
that may be employed. 

The natural colors of cayenne and paprika are sparingly soluble in 
alcohol, but readily soluble in carbon bisulphide. The separated alcohol 
is examined for colors by methods given elsewhere. 

Tests for coal-tar dyes should also be made by Sostegni and Carpen- 
tieri's, or Arata's method (Chapter XVII). 

Szigeti * treats the suspected sample with water acidified with acetic 
acid, and boils in this solution a bit of wool, which, if carotin or a coal-tar 
dye be present, is colored red. If the color is carotin, it will be removed 
from the wool by treatment with petroleum ether, or by heating at 100° 
C. for some hours, but if a coal-tar dye, it will still remain fixed thereon. 

Detection of Olive Oil in Red Pepper.— The color of paprika and 
pimiento is sometimes intensified by grinding with olive oil. This form 
of adulteration is detected by determination of the iodine number of the 
non-volatile ether extract. The usual method of determining the non- 
volatile ether extract having been found unsatisfactory for the purpose, 
Wintont suggested a method analogous to that employed by him and 
co-workers in determining alcohol in water extracts. The following 
details of the process, elaborated by Seeker,f have been adopted by the 
Association of Official Agricultural Chemists: 

Dry 5 grams on a watch-glass over sulphuric acid for at least twelve 
hours. Measure 250 cc. of anhydrous alcohol-free ether into a dry 
graduated flask with the mark near the lower end of the neck, and brush 
the paprika into it. Place a mark on the neck of the flask at the meniscus, 
and allow to stand for one hour, shaking at twenty-minute intervals 
during that time. Bring the meniscus back to the mark either by cooling 
if the level has risen, or by adding absolute ether if it has fallen, and let 
settle. Pipette off 100 cc. of the supernatant liquid, filter through an 
ii-cm. close-textured paper into a tared, air-dry glass-stoppered 250-cc. 
Erlenmeyer flask previously counterpoised against a similar flask, wash 

* Zeits. landw. Versuchs. Oesterreich, 5, 1902, pp. 1208, 1222. 
t U. S. Dept. of Agric, Br. of Chem., Bui. 122, 1909, p. 38. 
X Ibid., Bui. 132, 1910, p. 114; 137, 1911, p. 81. 



462 FOOD INSPECTION AND ANALYSIS. 

with a little absolute ether, and distil off the solvent until the ether ceases 
to come over. Lay the flask on its side in a water-oven, heat for thirty 
minutes, cool the open flask for at least thirty minutes in the air and 
weigh. Repeat this heating and weighing until the weight is constant 
to within i milligram, two heatings usually being sufficient, and calculate 
the per cent of ether extract. If more than il hours' heating is required 
to obtain constant weight or if the ether extract becomes colorless it 
should be rejected, and a new determination started with freshly purified 
ether. 

Dissolve the ether extract in the flask in lo cc. of chloroform, add 
30 cc. of Hanus solution, and proceed as described for the Hanus 
method. The iodine number thus determined should not be less than 125. 

GINGER. 

Nature and Composition. — Ginger as a spice is the ground root- 
stock of the Zingiber officiiiale, an annual herb of the family Zingiber- 
acecB, growing to a height of from 3 to 4 feet. It is a native of India and 
China, but is cultivated quite extensively in tropical America, Africa, 
and Australia. 

The root is dug when the plant is a year old, and when the stem has 
withered. If the root, when freshly dug and scalded to prevent sprout- 
ing, is dried at once, it forms the so-called black ginger, of which Calcutta 
and African are the common varieties. When decorticated, the product 
is known in commerce as white ginger, the chief varieties being Jamaica, 
Cochin, and Japan. The best variety is Jamaica ginger. The scraped 
root is sometimes bleached to make it still whiter, or sprinkled with 
carbonate of lime. 

In commerce whole or black ginger appears in " hands " 4 to 10 cm. 
long, and from 10 to 15 mm. in diameter. These usually have three or 
four various-sized, irregular branches, some short and thick, others 
elongated. The epidermis is gray or yellowish gray in color, more or 
less wrinkled, and beneath it is a reddish-brown layer. The inner portion 
of the dried root is white or yellowish. The root is hard, and of a com- 
pact, horny structure. 

White or decorticated ginger appears in " hands " of smaller diameter 
than the black, and yields a lighter colored powder on grinding. Preserved 
ginger root is prepared by boiling the root in water, and curing with sugar 
or honey. Much of the preserved ginger comes from Canton. 



SPICES. 



463 



The distinguishing features of ginger are its large content of starch, 
its volatile oil, and its resinous matter. Inasmuch as the epidermis con- 
tains a large amount of pungent resin, it is easy to see how the peeled or 
decorticated variety is inferior. 

Oil of ginger is very aromatic, and of a greenish- yellow color. Its 
specific gravity ranges from 0.875 '-O 0-885. It is slightly soluble in alco- 
hol. Of its composition little is known. 

Richardson's analyses in full of five samples of whole ginger-root are 
as follows: 



.- a! 









Calcutta 

Cochin 

Unbleached Jamaica 

Bleached Jamaica, London. . 
" " American 



9.60 

9.41 

10.49 

II .00 

10. II 



7.02 
3-39 
3-44 
4-54 

5-58 



2.27 
1.84 
2.0:5 
1.89 

2-54 



4-58 
4.07 
2.29 

3-04 
2.69 



49-34 
53-33 
50-58 
49-34 
50.67 



7-45 
•05 
74 
70 

65 



6.3c 

7.00 

10.85 

9.28 

9- 



13-44 
18.91 

15-58 
19.21 
11.66 



1. 01 
1. 12 

1-74 
1.48 
1.46 



Summaries of Winton, Ogden, and Mitchell's analyses of eighteen 
samples of whole ginger, representing the common white and black 
varieties, as well as of two samples of exhausted ginger, are as follows; 







Ash. 



u 

g 
'►J 


Ether Extract. 











> 


h 

"o 
> 

1- 


Ginger: Maximum 


11.72 

8.71 

10.44 

10.61 
8.02 


9-35 
3.61 

5-27 

2.12 

5-05 


4.09 

1-73 
2.71 

0-59 
3-55 


2.29 
0.02 
0.44 

0.18 
1.50 


3-53 
0.20 
0.80 


3-09 

0.96 

1.97 

1. 61 
0.13 


5-42 
2 82 


Minimum 


Average 


4.10 

3-86 
0-54 


Exhausted ginger from English ginger- 
ale works 


E.xhausted ginger from extract works . . 



Ginger: Maximum 

Minimum 

Average 

Exhausted ginger from English gin- 
ger-ale works. 

Exhausted ginger from extract works. 



6.58 

5.18 

4.88 
1-52 



Reducing 
Matters by 
Acid Con- 
version, as 
Starch. 


Starch by 
Diastase. 

Method. 


il 

urr, 



62.42 

53-43 

57-45 
59.86 



60. 31 1 5.50 
49-05' 2.37 
54-53' 3-91 

54-57. 5-17 



9-75 
4.81 

7-74 
6.94 



2T^ 



17-55, 1-55 
10.92 0.77 

13-42, 1.23 



6-15' 
16.42J 



I. II 



464 



FOOD INSPECTION AND ANALYSIS. 



McGill * records the analyses of ninety-eight samples of ground ginger 
as sold in the Canadian market. Of thirty-two of these, pronounced 
pure on analyses, the following is a summary: 





Moisture 
or Loss 
on Dry- 
ing at 

IOO°. 


Petro- 
leum- 
ether 
Extract. 


Cold- 
water 
Extract. 


Ash. 




Total. 


Soluble. 


Insoluble. 


Alkalin- 
ity of 
Soluble 
Ash as 
K2O. 


Maximum 


12.00 
9-50 


6.13 

2.78 


15-48 
14.04 


7.84 
3-67 


3-15 
2.28 


3-99 
1.96 


•133 
.103 


Minimum 





According to Vogl, the proportion of ginger ash varies quite widely 
according to the kind, but should never exceed 8%. 

Exhausted Ginger and Methods of Detection. — There are two kinds 
of exhausted ginger commercially available for admixture with ground 
spice, as an adulterant. One is the product left after extraction with strong 
alcohol in the making of extract of Jamaica ginger, and the other the 
residue from extraction with either very dilute alcohol, or with water, 
in the manufacture of ginger ale. Ground, exhausted ginger is rarely 
substituted wholly for the pure variety, since, from its lack of pungency, 
the sophistication would be too apparent. It is rather used to mix with 
the latter in varying proportions, and as an adulterant of other spices. 
Ginger that has been exhausted by extraction with alcohol has been 
deprived of most of its volatile oil, which is found in the "extract," while 
for the manufacture of ginger ale, a water extract, or at most a very dilute 
alcoholic extract is best adapted. Such a water extract does, as a matter 
of fact, remove much of the valued pungency, so that the residue, or 
exhausted ginger, is rather inert. 

Either the alcohol- or the water-extracted variety of exhausted ginger, 
when present in considerable amount, would be apparent, one by the 
alcohol and ether extract, and the other by the abnormally low cold- 
water extract, and water-soluble ash. 

Dyer and Gilhard f first called attention to the water-soluble ash as 
a reliable means of indicating exhausted ginger. Six samples of ginger 
of known purity were analyzed by them, their results being summarized 
as follows: 



* Dept. Inl. Rev. Canada Bui. 
t Analyst, 18, 1893, p. 197. 



pp. 10, II. 



SPICES. 



465 



Pure ginger (6 samples): Highest 

Lowest. 

Average 
Exhausted ginger (6 samples) : Highest 

Lowest. 

Average 





Water- 


Total Ash. 


soluble 




Ash. 


4-1 


3- 


3-1 


1.9 


3-8 


2-7 


2-3 


o-S 


I.I 


0.2 


1.8 


0.35 



Alcohol 

Extract, 

after Ether 

Extract. 

3-8 
2.1 

2.8 

1-5 
0.8 



Allen and Moor* pointed out the value of the cold-water extract 
as a help in detecting exhausted ginger, especially when taken in con- 
nection with the soluble ash, showing that the presence of this adulterant 
is assured, when the soluble ash is as low as i% and the cold-water extract 
is less than 8%. 

Determination of Cold-water Extract. — Winton, Ogden, and MitcheWs 
Melhod.-f — Four grams of the ground sample are placed in a 200-cc. 
graduated flask, and the latter is filled to the mark with water, and shaken 
at half-hour intervals during eight hours, after which it is allowed to 
stand at rest for sixteen hours in addition. The contents are then filtered, 
and 50 cc. of the filtrate evaporated to dryness in a platinum dish. It 
is then dried at ico° to constant weight and weighed. 

Microscopical Structure of Ground Ginger. — Fig. 87, from Moeller, 
shows elements of ginger root, from which the epidermis has not been 
removed. A bit of the large-celled cork (or dead protective tissue of 
the epidermis) is shown in surface view at (i); at (2) is shown in cross- 
section the parenchyma in which the starch is contained, h being an oil- 
cell; (3) shows the parenchyma in longitudinal section, with bast fibers. 
Fragments of spiral ducts are shown at (4), and starch grains at (5). (6) 
is a cross-section in the extreme interior of the root. 

The most prominent feature of powdered ginger is the starch grains 
(5), which Moeller compares#in shape to tied sacks. 

Fig. 228, PI. XXVII, is a photomicrograph of pure, ground ginger, 
mounted in water, showing the starch grains inclosed in the cells of the 
parenchyma. Fig. 231 shows the starch grains alone. The granules of 
ginger starch are ellipsoidal, and as a rule very clear and transparent, 
being for the most part entirely devoid of either hilum or concentric rings. 
Occasionally granules are to be found, however, with faint concentric 

* Analyst, 19, 1894, p. 194. 

t Conn. Agric. Exp. Sta. Rep., 1898, 190. 



466 



FOOD INSPECTION AND ANALYSIS. 



markings, and even with an apparent hilum. The characteristic form of 
the ginger starch granule is more or less egg-shaped, with a small protu- 
berance near one end. This protuberance serves to readily distinguish 
the starch granules of ginger from those of wheat, with which ginger 




Fig. 87. — Powdered Ginger under the Microscope. X125. (After Moeller.) 



is frequently adulterated. While wheat granules are of various sizes, 
the grains of ginger starch are as a rule much more uniform. 

U. S. Standards. — Ginger: Starch, not less than 42%; crude fiber, 
not more than 8%; lime (CaOj, not more than 1%; cold-water extract, 
not less than 12%; total ash, not more than 7%; ash insoluble in hydro- 
chloric acid, not more than 2%; ash soluble in cold water, not less than 
2%. Jamaica ginger: cold-water extract, not less than 15%, other- 
wise as for ginger. Limed ginger: calcium carbonate, not more than 
4% ; total ash, not more than 10% ; otherwise as for ginger. 

Adulteration. — Besides exhausted ginger, the common adulterants re- 
ported in powdered ginger are turmeric, wheat, corn, rice, and sawdust. 
Sawdust of soft wood was a not uncommon adulterant, and care should 
be taken to distinguish between the wood fiber natural to the ginger 
root, and that of the foreign variety. A careful study should be made 
of finely ground, soft-wood sawdust, with its long spindle cells and lateral 



SPICES. 



467 



pores, as shown in Fig. 266, PI. XXXVII, and the wood fiber of the genuine 
ginger root. A large admixture of sawdust would materially increase the 
percentage of crude fiber. 

Fig. 234, PI. XXIX, shows a sample of ginger adulterated with corn 
and wheat. Fig. 232 shows a mass of wheat bran in an adulterated 
sample. 

Fig. 233 shows ginger adulterated with turmeric* 



TURMERIC. 

Nature and Composition. — Turmeric, while largely used as an adul- 
terant of other spices (especially of ginger and mustard), possesses some 
value as a condiment in itself, forming, for instance, the chief ingredient 
of curry powder, f Turmeric {Curcuma Ion go) belongs to the same 
family {Zingiberacece) as ginger, having a perennial rootstock, and an 
annual stem. It is a native of the East Indies and Cochin-China. Its 
chief ingredients are starch, a volatile oil, a yellow coloring matter (cur- 
cumin), cellulose, and gum. 

Curcumin (C14H14O4) is insoluble in cold water, but readily soluble 
in alcohol. It is extracted from powdered turmeric by boiling the latter 
with water, filtering, and extracting the residue with boiling alcohol. 
The alcohol solution is filtered, evaporated, and the residue extracted 
with ether. The ether extract contains the curcumin, together with a 
small amount of volatile oil. 

Curcuma oil is an orange-yellow, slightly fluorescent liquid, its specific 
gravity being 0.942. 

The following analyses of turmeric were made in the writer's labo- 
ratory : 



Variety. 



China. . 
Pubna. . 
Alleppi. 

Average 



Mois- 
ture. 



9-03 
9.08 
8.07 

8.73 



Total 
Ash. 



6.72 
8.52 
5-99 

7.07 



Ash 
Soluble 
inWater. 



5.20 
6.14 
4-74 

5-3^ 



Ash 

Insoluble 

in HCl. 



Total 
Nitrogen. 



1-73 
0.97 

1.56 
1.42 



Protein. 
NX6.2S. 



10.81 
6.06 

9-75 



Total 

Ether 

Extract. 



10.86 
12.01 
10.66 

11.17 



* This photomicrograph is very disappointing, in that it fails to show the intense yellow 
of the central mass of turmeric. 

t Curry powder consists of a mixture of turmeric, cayenne, and various pungent spices. 



468 



FOOD INSPECTION AND ANALYSIS. 



Variety. 



Volatile 

Ether 

Extract. 



Non-vol- 
atile 
Ether 
Extract. 



Alcohol 
Extract. 



Crude 
Fiber. 



Reducing 
Matter by 
Acid Con- 
version , as 
Starch. 



Starch by 
Diastase 
Method. 



China. . 
Pubna. . 
Alleppi. 

Average 



2.0I 

4.42 
3.16 

3-19 



8.84 
7.60 
7-51 

7.98 



9.22 
7.28 
4-37 

6.96 



4-45 
5-84 
5-83 

5-37 



48.69 
50.08 
50-44 

49-73 



40.05 
29.56 
33-03 

34.21 



Microscopical Structure of Turmeric. — Moeller's representation of 
characteristics of powdered turmeric is reproduced in Fig. 88. The 




Fig. 



■Powdered Turmeric under the Microscope. X125. (After Moeller.) 



epidermis is shown at (i) with one of the numerous, one-celled hairs that 
grow from it, also the scar left after one of the hairs has been removed; 
(2) shows in plan view the cork immediately under the epidermis. The 
tender-celled parenchyma is shown in cross-section at (3), and in longi- 
tudinal section at (4). In some of the cells of the parenchyma are found 
dark-yellow lumps of resin {h), and vascular ducts (g), but by far the most 
numerous and striking contents of the parenchyma-cells are the bright- 



SPICES. 469 

yellow masses of " paste balls " (^a) and the starch granules, one of which 
is shown in (3). See also Plate XIII. The starch grains in the water- 
mounted powder show under the microscope in masses, usually of a deep- 
yellow color, unless very finely rubbed out, when they appear for the most 
part in fragments. 

The whole starch granule appears somewhat in the form of a clam-shell, 
with very distinct markings. When fragments of the starch granules are 
carefully examined, these distinct markings are so strongly characteristic, 
even in the smallest pieces commonly found in the powdered sample, 
as to nearly always serve to identify them. See Fig. 171, Plate XIII. 

Turmeric as an Adulterant. — Turmeric is a material especially adapted 
by its deep-yellow color to intensify mustard and ginger, especially when 
these spices are adulterated with the lighter-colored cereal starches, hence 
formerly it was used in these spices, both with and without other adulterants. 

It was also frequently used in small quantities in adulterated cayenne, 
mace, and various -spices, to counteract the colors of other dyestuffs, 
such as ground redwood, which in itself would sometimes be too intense 
if used alone. 

MUSTARD. 

Nature and Composition. — Mustard is the seed of the mustard plant, 
an annual belonging to the family CrucifercB, and to the genus Sinapis, 
or Brassica, as it is now generally known. The mustards include wild 
and cultivated species all with yellow flowers and Ijn-ate leaves. 

The common species are black, sometimes called brown, mustard 
(B. nigra), brown or Serepta mustard (B. Besseriana), white or yellow 
mustard, {B. alba), and Indian mustard {B. jimcea). The seeds of char- 
lock {B. arvensis), growing wild in the grain and flax fields of the North- 
west, together with brown mustard, are separated from the grain by in- 
genious machines and constitute the so-called wild mustard of commerce.* 

The seeds of all varieties are globular, those of the black mustard 
being smaller than those of brown, and both smaller than those of white 
mustard. As seen under the lens the surface of black, brown, and Indian 
mustard is reticulated, while that of white mustard and charlock is smooth. 
Most of the seeds of charlock are of a deep black color. 

Both black and white mustard contain from 27 to 38% of fixed oil, 
a soluble ferment known as myrosin, and a sulphocyanate of sinapin. 
Mustard seeds contain no starch, and very little volatile oil as such. Black 

* Jour. Ind. Eng. Chem., 7, 1915, p. 684. 



470 FOOD INSPECTION AND ANALYSIS. 

mustard seed contains sinigrin, or myronate of potash (not found in the 
white seed), which, when moistened with water, forms by hydrolysis 
the volatile oil of black mustard, otherwise known as allyl isothiocyanate, 
in accordance with the following equation: 

KC10H16NS2O9 +H2O = CeHisOe +C3H5CNS +KHSO4. 

Potassium Glucose Mustard Potassium 

myronate oil bisulphate 

Mustard Oil (volatile) is a colorless, or slightly yellow, highly refrac- 
tive liquid of a very strong odor, and capable of blistering the skin when 
brought in contact with it. It is optically inactive. Its specific gravity 
varies between 1.016 and 1.030. It boils between 148° and 156°. It 
turns reddish brown by exposure to light. 

Volatile oil of black mustard forms thiosinamine with ammonia, as 
follows : 

CaH.CNS +NH3= CS.NH2.NH.C3H5. 

Thiosinamine is soluble in hot water, from which it crystallizes in 
tufts of monoclinic crystals, having a melting-point of 74° C. It is pre- 
cipitated by silver nitrate, mercuric chloride, and Mayer's solution. 

White mustard differs from the black in containing a sulphur com- 
pound, sinalbin, C30H42N2S2O15. This is a glucoside. Sinalbin by hy- 
drolysis forms an oil of white mustard, in a somewhat similar manner 
to the potassium myronate of black mustard, and according to the follow- 
ing equation: 

C3oH,2N2S30i5+ H,0 = C,H,ONCS + CeH^^O^ + C.eH^.NO.HSO,. 

Sinalbin Sinalbin Glucose Sinapinacid 

mustard oil sulphate 

Sinalbin Mustard Oil cannot be obtained by the distillation of white 
mustard, being sparingly volatile with steam. 

Sinalbin mustard oil somewhat resembles that from black mustard, 
being quite as pungent, but less strong in odor when cold. It is soluble 
in dilute alkali. 

Fixed oil of mustard is a bland, tasteless, and nearly odorless oil, its 
specific gravity at 15° varying between the hmits of 0.914 to 0.918. It 
is said to be used to some extent as an adulterant of table oils, being 
separated by pressure from the crushed mustard seeds before the latter 
are ground into "flour." The chief use of mustard oil is in mixture 
with other oils as an illuminant. 

MUSTARD Flour. — In the process of preparing the ground spice com- 
monly known as mustard "flour," the seeds are first crushed and sepa- 



SPICES. 



471 



rated by winnowing from the hulls, the latter being incapable of the fine 
grinding necessary to produce a smooth flour. The yellow hulls are, 
however, found in the cheaper grades of ground mustard, and both 
varieties of hull are frequently used in the wet mustard preparations, 
sold in bottled form. In order to produce an even, dry powder, free from 
lumps, it is necessary to remove a large portion of the fixed oil, which 
is indeed of no value in the final product, and this is done by subjecting 
the crushed material to hydraulic pressure, during which process the 
mustard is molded together into thin, hard plates, called "mustard 
cake." This is then broken up and reduced to fine powder by pounding. 
Richardson's* analyses of whole-seed flour, prepared by himself 
without the removal of the fixed oil, are as follows: 



c4^ 





.d 


<a M 




1;^ 1" 








M 


•S.S 


fe 


W 





< 





33-56 


.00 


S-40 


28.88 


21-33 


34 -«3 


.00 


9-05 


25-56 


20.16 


28.12 


.00 


9-50 


23-44 


27.23 


31.96 


.00 


8-50 


31-13 


16.35 


36.63 


.00 


16.18 


24.69 


12.16 


31-51 


.00 


6.90 


30-25 


22.10 


39-55 


.00 


10.84 


25.88 


18.87 



White seed 

White flour 

Seed husk 

CaHfornia yellow, 
California brown, 
English yellow . . 
Trieste brown. .. 



5-57 
3-23 
6.17 

4-83 
4. II 

3-11 
4.62 



4-29 
5-23 
4-99 
5-96 
4.88 
4.07 
5-6i 



-97 
1.84 

-55 
1.27 

1-35 
2.06 

-63 



4.62 
4.09 

3-75 
4.98 
3-95 
4.84 
4.14 



Winton and Mitchell made no full analyses of mustard seed of known 
purity, but the following is a summary of analyses of 18 samples of com- 
mercial mustards, sold in packages in Connecticut, and not found to be 
adulterated: 



Total 

Ash. 



Ether Extract. 



Volatile. 



Non-vol- 
atile. 



Reducing 






Matters 


Starch 




by Acid 


by 


Crude 


Con ver- 


Diastase 


Fiber. 


sion, as 


Method. 




Starch. 






6.12 


2.08 


4.87 


1.85 


0.28 


1.58 


4-33 


1.07 


2.58 



Nitrogen 
X6.25. 



Maximum 
Minimum 
Average.. 



7-35 
4.81 

5-99 



1.90 
0.00 
0.56 



28.10 
17.14 
20.61 



43-56 
35-63 
39-57 



The following analyses of 5 samples of mustard flour, 6 samples of 
mustard hulls, and 6 samples of whole mustard, were made in the author's 
laboratory in 1903: 



U. S. Dept of Agric. Div of Chem.. Bui. 13, part 2. 



472 



FOOD INSPECTION AND ANALYSIS. 





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Mustard "flour" as pre- 
pared commercially: * 

English brown 

California brown 


Av. of brown flours. . 

German yellow 

California yellow 

Av. of yellow fi9urs. . 
Average of all varieties 

of flonr. . . 


>y • 

•d S'M 


3 

a 

> 
>■ •■ 

<<: 

2 


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alls 
Top 


English yellow 

California yellow 

Av. of yellow seeds. . 

Average of all six sam- 
ples of seeds 





SPICES. 473 

Piesse and Stansell give the following composition of mustard ash: 





White Seeds. 


Brown Seeds. 


Yorkshire. 


Cambridge. 


Cambridge. 


Potash 


21.29 
0.18 

13-46 
8.17 
1. 18 
7.06 
O.II 

32-74 

1. 00 

1.82 
12.82 


18.88 
0.21 

9-34 
10.49 

1-03 
7.16 
0.12 
35-00 
1. 12 

1-95 
15-14 


21 .41 
0-35 

13-57 

10.04 
1.06 
5 -56 
0.15 

37.20 
1. 41 
1.38 
7-57 


Soda 


Lime 


Magnesia 


I ron oxide 


Sulphuric acid 


Chlorine 


Phosphoric acid 


Silica 


Sand 


Charcoal 




99-85 


100.48 


99.70 



Determination of Potassium Myronate, Sinapin Thiocyanate, and 
Myrosin. — Leeds and Everhart Method.^ — Dry 10 grams of the sample 
at 105° C, remove the fat with absolute ether, and extract the potassium 
myronate and sinapin sulphocyanate from the residue in a continuous 
extractor with a mixture of equal parts of alcohol and water. Evaporate 
the extract in a tared dish, and dry the combined sulphur compounds 
at 105° C. to constant weight. Incinerate at a temperature sufhciently 
ligh to transform the potassium bisulphate, resulting from the decom- 
position of the myronate, into the neutral sulphate. Multiply the weight 
of the ash by 4.77, thus obtaining the weight of potassium myronate. 
This, deducted from the total weight of the dried alcoholic residue, gives 
that of the sinapin sulphocyanate. 

Remove the alcohol from the residue after the alcoholic extraction, 
as above described, and treat with 0.5% sodium hydroxide solution, thus 
dissolving the myrosin. Filter, nearly neutralize the filtrate with dilute 
hydrochloric acid, add 50 cc. of Ritthausen's copper sulphate solution, 
and nearly neutralize with dilute sodium hydroxide solution. Collect the 
heavy green precipitate of copper myrosin on a tared filter, dry at 110° 
C, and weigh. Ignite, weigh again, and deduct the weight of the ash 
from the total weight, thus obtaining the weight of the myrosin. 

Determination of Volatile Mustard Oil. — Roeser Method.f — Mix 5 
grams of the sample with 60 cc. of water and 15 cc. of 60% alcohol, and 

*Zeits. anal. Chem., 21, 1882, p. 389. 
t Jour, pharm. chim, [6], 15, 1902, p. 361. 



474 FOOD INSPECTION AND ANALYSIS. 

let stand for 2 hours. Distil into a flask containing 10 cc. of ammonia, 
and, after about two-thirds of the solution have been distilled off, mix 
the ammoniacal distillate with 10 cc. of tenth-normal silver nitrate solu- 
tion, and allow the mixture to stand for 24 hours, after which make up 
with water to 100 cc. Filter, and treat 50 cc. of the filtrate with 5 cc. 
of tenth-normal potassium cyanide solution. Titrate the excess of cyanide 
with the tenth-normal silver nitrate, using as an indicator a 5% solution 
of potassium iodide, made slightly ammoniacal. 

Calculate the percentage of mustard oil, containing 93% of allyl iso- 
thiocyanate, (P), by the following formula: * 

^^^Xo.oo4957X2Xioo^^^^^ 
0.93X5 "* 

in which A = t\ie number of cc. of N/io silver nitrate required for the 
final titration and 0.004957 = the weight of allyl isothiocyanate corre- 
sponding to I cc. of N/io silver nitrate. 

To obtain the results in terms of allyl isothiocyanate, as recommended 
by Boutron,t omit 0.93 from the above formula or employ the factor 
0.1983 instead of 0.2132. 

The Kimtze Method, like that of Godamer and others, employs am- 
monium thiocyanate for the titration. The method, as applied to mus- 
tard oil, J was adopted by the committee on the ninth revision of the 
United States Pharmacopoeia and, as applied to mustard seed, by the 
Bureau of Chemistry. § In details of distillation, it is the same as the 
Roeser method, except that 5 grams of the sample are macerated for 
2 hours at 37° C. with 100 cc. of water, 20 cc. of 95% alcohol are used, 
and the distillation is begun at once and continued until 60 cc. have passed 
over. To the distillate 20 cc. of N/io silver nitrate are added and, after 
standing over night, the mixture is heated to boiling to cause the silver 

• * The conversion factor given in former editions of this work, taken from an abstract 
of Roeser's paper published in the Analyst (27, 1902, p. 197), was nearly three times too high. 
Attention to this error was directed by Mr. M. C. Albrech, chemist of the R. T. French 
Co., mustard makers, Rochester, N. Y., and Mr. A. E. Paul, of the U. S. Food Laboratory, 
Chicago. This same erroneous factor is given in the fourth edition of Allen's Commercial 
Organic Analysis and other works, and appears to have vitiated the results of several in- 
vestigations. In the present edition the analytical results by Leach and by Winton and 
Bornmann, as well as the factor itself, have been corrected. A. L. W. 

t Bui. sci. pharm., July, 191 2; Ann. chim. anal., 18, 1913, p. 61. 

X Arch, pharm., 246, 1908, p. 58; Allen's Coml. Org. Anal., 4 ed., 7, 1913, p. no. 

§ Service and Regulatory Announcements, 20, 1907, p. 59. 



SPICES. 



475 



sulphide to flock, cooled, made up to loo cc, shaken, and filtered. Fifty 
cc. of the filtrate are mixed with 5 cc. of concentrated nitric acid, titrated 
with N/io ammonium thiocyanate solution, using 5 cc. of 10% ferric 
ammonium sulphate solution as indicator. 

Microscopical Characteristics of Powdered Mustard.— The principal 
features of powdered black mustard are represented in Fig. 89- The 

seed shell or hull is shown in cross-section 
at (i), a being the polygonal-celled epi- 
dermis, h a layer of palisade-shaped cells, 
and c a thin pigment layer, the brown 
coloring matter of which is colored blue by 
iron salts; d is the aleurone layer and ob- 
scure parenchyma, and e the small-celled 
tissue of the cotyledons, containing fixed oil 
and albumen. 

(2) shows in surface view the various 
layers of the seed shell, the letters of 
reference corresponding to those of (i). 

(3) shows in surface view a bit of the 
extreme outer mucilaginous layer of the seed- 
hull. 

Fig. 247, PI XXXII, shows the ap- 
pearance in water- mount of pure ground 
mustard. This is a photomicrograph of the ground hulled seed with- 
out the extraction of the oil, and should not be taken as a standard 
for commercial mustard "flour," from which, as a rule, a large por- 
tion of the oil has been removed. The cellular tissue of the mustard 
shows in the form of granular masses of loose, fine gray texture; the 
globular bodies are oil drops. Here and there through the field of 
ordinary ground mustard are to be seen patches of the yellowish layer 
3f the seed skin of the brown mustard, a mass of which is shown in 
Fig. 248, with dark-brown spots distributed regularly through it. This 
is the layer shown at (2) h, Fig. 89. The hull of the yellow seed, also 
common in powdered mustard, is similar in appearance, having dark- 
brown spots, but with nearly colorless or gray cell walls, instead of yellow. 
Patches of the outer hull layer represented by (3) in Fig. 89 are also 
very common in the commercial mustard flour. Mustard contains no 
starch. 




Fig. 89. — Powdered Mustard 
under the Microscope. X12S. 
(After Moeller.) 



476 FOOD INSPECTION AND ANALYSIS. 

U. S. Standards for mustard flour are as follows: Starch, by diastase 
method, should not exceed 1.5%, and total ash should not exceed 6%. 
Mustard seed should not contain more than 5% of total ash nor more 
than 1.5% of ash insoluble in hydrochloric acid; black mustard seed 
and related types yield not less than 0.6% of volatile mustard oil. 

Adulteration of Mustard. — It is difficult to draw the line between the 
amount of mustard hulls which may naturally occur in ground mustard, 
and the excess amount which is sometimes added as an adulterant. 

In determining starch in mustard, it should be borne in mind that 
mustard hulls have considerable reducing matter by the diastase process, 
although no true starch is evident by microscopic examination or the 
iodine tests. 

At one time much of the mustard in the American market contained 
cereal flour, gypsum, or other makeweights, artificial colors, notably 
turmeric, being used to cover the fraud. Pure uncolored mustard is now 
everywhere obtainable. 

Wild Mustard, consisting of charlock and brown mustard, grows 
luxuriantly in the grain fields of the Northwest and the seed is a common 
impurity of the uncleaned wheat from that region. It is an important 
constituent of wheat screenings, from which it is separated and placed on 
the market under such names as " Dakota mustard," " Domestic mustard," 
etc. The brown mustard has been shown by Kate Barber Winton * to 
be B. Besseriana and not as has been generally believed B. juncea. The 
product also contains other weed seeds, notably those of the mustard 
family, and also a certain amount of broken wheat. 

The following table by Winton and Bornmann f gives botanical anal- 
yses and results of determinations of volatile mustard oil in samples of 
pure mustards and wild mustard separated from screenings. In addition 
to percentages of volatile oil by Roeser's method are given figures obtained 
by calculation from the botanical analyses by the following formula: 

F = 0.00825 4- 0.0005C, 

in which V is percentage of volatile oil, B is percentage of brown mustard, 
and C is percentage of charlock. 



* Winton's Microscopy of Vegetable Foods, 2 ed., New York, 1916, 183. 
t Jour, Ind. Eng. Chem., 7, 1915, p. 684. 



SPICES. 



477 



BOTANICAL ANALYSES AND VOLATILE OIL CONTENT OF CULTIVATED 
AND WILD MUSTARD SEED. 



As Separated. 



Botanical Analysis. 



Calculated Free of Foreign Seeds. 



Botanical Analysis. Volatile Oil. 



Charlock. 



Brown 
Mustard. 



Foreign 
Seeds. 



Charlock. 



Brown 

Mustard. 



Actual 
Deter- 
mination. 



Calc. 

from 

Botanical 

Analysis. 



Pure charlock. 



Pure brown mustard 
Pure black mustard . 
Pure white mustard. 
Commercial wild mustard 
Separated from— 

Flaxseed 

Barley 



Wheat. 



Unknown . 



ICO 
I CO 



o 

IOC 



99-5 
4-7 

10.7 
9.0 

12.9 

8-5 
18.2 
35-8 
27.6 
24-5 

2-5 

9.0 
28.5 
18. 1 



4.8 

1-3 

5-8 
50 
4.0 
6.1 
16.4 

iS-i 
2.0 

10.9 
2.0 

5-3 
0.8 



100 

100 

o 



o.S 
95 I 
89.1 
90.4 
86.4 
91 . 2 
80.6 
57-3 
67-5 
75-0 
97.2 
90.8 
69.9 



99- 5 

4-9 

10.9 

9.6 

13.6 

8.8 

19.4 

42.7 

32.5 

25.0 

2.8 

9.2 

30.1 

II. 9 



0.05 
0.09 
0.98 

1-57 
0.05 



0.82 
0.08 
0.13 
o. 12 
o. 14 

O. II 

o. 19 

0-39 
0.32 
0.31 
0.06 

015 
0,31 
o. 16 



0.09 
o. 14 

0.13 
0.16 

O. 12 
0.20 
0.38 
0.30 
0.24 
0.07 
0.12 
0.28 
0.14 



Mustard flour is often made from wild mustard or a mixture of mustard 
seeds containing wild mustard. If the latter consists in large part of 
charlock, the product is doubtless inferior, since this seed has a rank 
flavor; on the other hand, if wild mustard shows a preponderance of 
brown mustard, it is well adapted for use as a spice. 

Charlock is identified by the presence in the palisade cells of a black 
substance which on heating in various acid reagents (such as chloral 
hydrate, glycerine, or zinc chloride, acidified with hydrochloric acid, 
syrupy phosphoric or citric acid), becomes bright carmine. A satisfactory 
reagent is a solution of 16 grams of chloral hydrate in 10 cc. of water and 
I cc. of concentrated hydrochloric acid. Mount 10 mg. of the material 
in a drop of the reagent, heat gently and examine under a lens. 



478 



FOOD INSPECTION AND ANALYSIS. 



Detection of Coloring Matter. — Turmeric is best detected by the 
microscope (see pages 468 and 469). Oil-soluble coal-tar dyes should be 
tested for as in the case of cayenne. Nitro colors, such as naphthol yellow 
(Martius yellow) and naphthol yellow S, are detected by dyeing tests, with 
subsequent examination of dyed fabric according to directions given in 
Chapter XVII. 

Prepared Mustard. — This product consists of a mixture of ground 
mustard seed or mustard flour with salt, spices, and vinegar. The U. S. 
standards require that it should contain not more than 24% of carbo- 
hydrates calculated as starch, not more than 12% of crude fiber, and not 
less than 5.6% of nitrogen. 

Most of the product consumed in the United States is of domestic 
manufacture, although until the passage of the federal food law it was 
customary to designate it German or French mustard, or label it in a foreign 
language. 

Composition and Adulteration. — The common admixtures are wheat 
flour, maize flour, and other starchy matter, mustard hulls, sugar, chemical 
preservatives, and artificial colors. 

Of 28 brands examined in Connecticut in 1905 by Winton and 
Andrew,* 13 contained cereal flour (wheat or corn), 4 salicylic acid, 
and 25 artificial color (turmeric, nitro-color or azo-color). A summary 
of the analyses of those brands free from cereal flour and those containing 
it follows: 



In the Material as Sold. 



Water. 



Acid- 
ity 
Calcu- 
lated 

as 
Acetic 
Acid. 



Total 
Solids. 



Total 
Ash. 



Com- 
mon 
Salt. 



Ash 
other 
than) 
Salt 



Pro- 
tein. 



Crude 
Fiber. 



Reduc- 
ing 
Matters 
by Acid 
Conver 
sion, as 
Starch. 



Nitro- 
gen- 
free 
Ex- 
tract. 



Fat. 



Prepared mustard free 
from cereal flour ; 

Maximum 

Minimum 

Average 

Prepared mustard con- 
taining cereal flour : 

Maximum , 

Minimum , 



83.68 
73-OI 
78.59 



85.63 
70.44 



3.66 
2.74 
3.05 



3 54 
1.86 



23.67 
13-32 
18.36 



37 . 70 
9.89 



4-79 
2.60 
3.38 



3 69 
1.78 
2.32 



3-39 
1.51 



1-31 
0.82 
1 .06 



I. 16 
0.48 



6. 12 
3.62 

4.71 



6.38 
I 53 



1.68 

0.77 
I. 17 



1-59 
o. 22 



2 .92 
1.83 
2 . 40 



13.69 



15.35 
3.82 



7.23 
2 . 12 
4 . 12 



3.2s 
o. 76 



Ann. Rep. Conn. Exp. Sta., 1905, p. 123. 



SPICES. 



479 



In the Dry, Fat, and Salt-free Material. 



Ash. 



Protein. 



Crude 
Fiber. 



Reducing 
Matters 
by Acid 
Conver- 



Nitrogen- 

free 
Extract. 



Prepared mustard free from cereal flour: 

Maximum 

Minimum 

Average 

Prepared mustard containing cereal flour: 

Maximum 

Minimum 

Whole mustard sood (analyses by the author 
See page 472): 

Maximum 

Minimum 

Average 



10. 66 
7-3S 
8.94 



0.68 
4.84 



7.64 
6.28 
6.83 



43-94 
32 .01 
39-44 



33-89 
21-37 



48.31 
37.50 
44>3I 



14.12 

7-77 
9-89 



18.44 
0.4S 



IO-33 
7.24 
S.Oj 



24-37 
16.82 
20. 1 1 



59-22 

24-51 



IS-9I 

11-94 
13-82 



44 76 
34.98 
41-73 



66.42 
41.79 



48. ss 

37.84 

40.81 



The following methods for the analysis of prepared mustard were 
used by Winton and Andrew, and afterwards adopted by the Association 
of Official Agricultural Chemists: 

Determination of Solids, Ash, and Salt is carried out in one portion of 
5 grams of the thoroughly mixed material, following the usual methods. 
The salt is calculated from the percentage of chlorine. 

Determination of Ether Extract.— Place lo grams of the material and 
about 30 grams of sand in a capsule, and dry on a water bath with stir- 
ring. Grind the dried residue and extract with anhydrous ether in the 
usual manner. 

Determination of Reducing Matters by Acid Conversion. — Treat 
the material directly, without previously washing, as described on page 

425- 

Determination of Fiber. — Treat 8 grams of the material (equivalent 
to about 2 grams of dry matter) as described on page 286, except that (i) 
the boiling 1.25% acid is added directly to the material without previous 
extraction, taking care to introduce it in small portions and shake thoroughly 
until all lumps are broken up, and (2) the fiber after collecting on the 
weighed paper is washed twice with alcohol and finally with ether until 
all fat is removed. If these precautions are not followed the results will 
be high. 

Determination of Protein. — Nitrogen is determined by the Kjeldahl 
or Gunning method, and the result multiplied by 6.25. 

Detection of Dyes and Preservatives. — See chapters XVII and 
XVIII. 



480 FOOD INSPECTION AND ANALYSIS. 



NUTMEG AND MACE. 

Nature and Production. — Both nutmeg and mace occur in the fruit 
of several varieties of trees of the genus Myristica, especially of Myris- 
tica fragrans or Myristica moschata, belonging to the family Myristi- 
cacecE. The nutmeg tree is a native of the Malay archipelago, and grows 
from 20 to 30 feet high, somewhat resembling the orange tree in appear- 
ance. It does not produce flowers till its eighth or ninth year, after which 
it bears fruit constantly for many years. The fruit is a globular, pendant 
drupe, about 5 cm. in diameter, of a yellowish-green color, the pericarp 
of which, when ripe, splits in two, showing within it the seed, completely 
surrounded by a fleshy, fibrous aril, or covering of a crimson color. This 
covering, when dried, furnishes the mace of commerce, while the kernel 
of the hard, brown seed is the nutmeg. 

The seed as separated from the fruit is surrounded by a thick tegu- 
ment, marked with depressions corresponding to the lobes of the aril or 
mace, and by a second thin, inner envelope, closely adhering to the seed. 
The whole seed is dried in the sun for about two months, or by the aid of 
heat, the tegument becoming separated from the kernel, and, by breaking 
with a hammer, is readily removed. The kernels are then commonly 
washed in milk of lime, and again dried, or they are sometimes treated 
with dry, powdered, air-slaked lime. Liming is alleged to prevent sprouting 
and ward off the attacks of insects. The so-called brown nutmegs of 
commerce are those which have not been treated or coated with lime. 

Nutmegs. — True nutmegs, the seed kernel of M. fragrans, are spher- 
oidal, sometimes nearly spherical, from 20 to 25 mm. long and 15 to 18 
mm. in diameter. The outer surface is somewhat furrowed. A cross- 
section of the kernel shows the grayish-brown, starchy endosperm, mottled 
with the dark-brown, resinous veins of the perisperm. These veins on 
pressure with the finger nail present an oily appearance. Near the end 
of the nutmeg which is attached to the stem, is a small cavity, in which 
is the undeveloped embryo with two cotyledons. 

Macassar, or long nutmegs, the seed kernel of M. argentea, are more 
elongated than true nutmegs and are inferior in flavor. 

Nutmeg contains a considerable amount of fixed oil, a volatile oil, 
starch, and albuminous matter. Its volatile oil is colorless, and is soluble 
in three parts of strong alcohol. The specific gravity of nutmeg oil 
varies between 0.865 and 0.920,, and its specific rotary power (a')z)= 14 
to 28. 



SPICES. 481 

Richardson's analyses of three samples of nutmeg are as follows: 





Water. 


Ash. 


Volatile 
Oil. 


Fixed 
Oil or 
Fat. 


Starch, 

etc. 


Crude 
Fiber. 


Albu- 
minoids. 


Nitro- 
gen. 


Whole limed , , 


6.08 
4.19 
6.40 


3-27 
2.22 

3-15 


2.84 

3-97 
2.90 


34-37 
37-30 
30.98 


36.98 
40.12 
41-77 


11.30 
6.78 
9-55 


S-16 
S-42 
5-25 


•83 
.87 
.84 


Ground limed 


Ground 





Konig gives the following minimum and maximum composition of 
nutmeg : 





Minimum, 


Maximum. 


Water 


4.2 
5-2 
2-5 
31.0 
29.9 
6.8 
2.2 


12.2 
6.1 
4.0 

37.3 

41.8 

12.0 

3-3 


Albuminoids 


Volatile oil 


Fat 


Carbohydrates 


Cellulose 


Ash 





Winton, Ogden, and Mitchell analyzed four samples of nutmeg of 
known purity, the following being maximum and minimum results: 





Moisture. 


Ash. 


Ether Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl. 


Volatile. 


Non-vola- 
tile. 


Maximum 


10.83 
5-79 


3.26 
2.13 


1.46 
0.82 


O.OI 

0.00 


6.94 
2.56 


36-94 
28.73 


Minimum 







Alcohol 
Extract. 


Reducing 
Matters by 
Acid Con- 
version , as 
Starch. 


Starch by 
Diastase. 


Crude 
Fiber. 


Nitrogen 
X6.2S. 


Total 
Nitrogen. 


Maximum , 


17-38 
10.42 


25.60 
17.19 


24.20 
14.62 


3-72 
2.38 


7.00 
6.56 




Minimum .............. 


1.05 





Microscopical Structure of Nutmeg. (Fig. 90.)— The thin- walled 
cells of the parenchyma of the endosperm or albumen are shown at 
(i), with starch grains. Simple and compound granules of the starch are 
shown at (2). Aleurone grains appear as shown at (3), and (4) represents 
in surface view the epidermis, or brown seed coat, with its numerous 
layers of flat cells. Powdered nutmeg under the microscope in water- 
mount shows most commonly a sponge-like, loose meshwork of bruised 



482 



FOOD INSPECTION AND ANALYSIS. 




Fig. go. — Powdered Nutmeg 
under the Microscope. X 1 25 . 
(After Moeller.) 



or broken cellular tissue, with many starch granules, and occasional 
fragments of the epidermis. 

Fig. 240, PI. XXX, is a photomicrograph 
of a water-mounted sample of pure nutmeg. 
The starch granules of nutmeg are different 
from other starches in appearance, being 
almost circular as a rule, quite uniform in 
size (averaging 0.006 mm. in diameter), and 
having very distinct central hyla. 

The U. S. Standards for nutmegs are 
as follows: Non- volatile ether extract should 
be not less than 25%; total ash should not 
exceed 5%; ash insoluble in hydrochloric acid 
should not exceed 0.5%; crude fiber should not exceed 10%. 

Adulteration of Nutmeg. — Nutmegs are usually sold whole, since the 
housewife much prefers to grate the whole nutmeg, rather than to use 
the ground material. It is hence less liable to adulteration than the 
other spices, though of late more of the ground nutmeg is being sold 
in packages. Samples of ground nutmeg have been found in Massa- 
chusetts adulterated with wheat and nutshells. One sample was found 
to contain at least 25% of ground cocoanut shells. 

Nutmegs which have become mouldy, or have been eaten out by 

insects, have been imported for grinding, as sound nutmegs are not readily 

reduced to a powder. Such a product is obviously unfit for consumption. 

An inferior variety is known as the Macassar nutmeg. This lacks 

much of the agreeable pungency of the better grades. 

Mace. — The crimson-colored aril that surrounds the nutmeg kernel 
within the pericarp, as above described (p. 480), has many narrow, 
flattened lobes. In the process of drying to form the mace of commerce, it 
loses its brilliant red color, and turns a yellowish brown. When dried, it is 
brittle, somewhat translucent, and of a pungent odor. Whole mace appear 
on the market in the form of flat membranous masses, 3 to 4 cm. long. 

Macassar mace has a characteristic wintergreen taste. Bombay mace 
is lacking in spicy flavor. 

Mace contains no starch as such, but a modified form of starch known 
as amylodextrin. This is a carbohydrate, C36H62O31 +H2O, which pro- 
duces with iodine a red coloration. Mace has a large amount of fixed 
oil, as well as considerable resinous and albuminous matter, and a vola- 
tile oil which much resembles that of nutmeg. 



SPICES. 



483 



The specific gravity of volatile oil of mace is rather higher than that 
of nutmeg oil. Its specific rotary power, («)o= lo to 20. 
Konig's figures for the composition of mace are as follows: 



Water 

Protein (iVX6.25) 

Volatile oil 

Fat 

Carbohydrates . .. 

Cellulose 

Ash 

Alcoholic extract . 



Minimum. 


Maximum. 


4-9 


17.6 


4-6 


6.1 


4.0 


8.7 


18.6 


29.1 


41.2 


44-1 


4-5 


8.9 


1.6 


4-1 


45-1 


55-7 



Richardson gives the following as the results of analyses of three 
samples made by him : 



Water. 



Ash. 



Volatile 
Oil. 



Resin. 



Unde- 
ter- 
mined. 



Crude 
Fiber. 



Protein 
(ATX 
6.25). 



Nitro- 
gen. 



Whole mace . 
Ground mace, 
Ground mace. 



5-67 

4-86 

10-47 



4-IO 
2.65 
2.20 



4.04 
8.66 
8-68 



27.50 
29.08 
23-33 



41.17 

35-50 
34-68 



8.93 
4-48 
6.88 



4-55 
6.13 
5.08 



•73 
.98 
.81 



Winton, Ogden, and Mitchell's analyses of four samples of pure Banda 
or Penang mace, as well as of Bombay and Macassar mace, are sum- 
marized as follows : 





Moisture. 


Ash. 


Ether Extract. 




Total. 


Soluble in 
Water. 


Insoluble 
in HCl 


Volatile. h^°"J°.'^" 


True mace : Maximum 

Minimum 

Average 

Macassar 


12.04 
9-78 

II-O^ 

4.18 
0-32 


2-54 
1. 81 

2-01 
2-OI 
1.98 


^■33 
1.06 

1-13 
I- II 

1-37 


0,-2 1 
0.00 
0.07 
0.03 
0.07 


8-65 
6.27 
7-58 
5-89 
4-65 


23-72 
21.63 
22-48 

53-54 
59-81 


Bombay (adulterant) 





Alcohol 
Extract. 


Reducing 
Matters by 
Acid Con- 
version, as 
Starch. 


Starch by 
Diastase.* 


Crude 
Fiber 


Nitrogen 
X6.25. 


Total 
Nitrogen. 


True mace : Maximum 

Minimum 

Average 

Macassar 


24-76 
22-07 
23.11 
32.89 
44-27 


34-42 
26-77 

31-73 
10-39 
16-20 


30-43 
23.12 
27-87 
8-78 
14-51 


3-85 
2.94 
3-20 

4-57 
3.21 


7.00 
6.25 

6-47 
7.00 
5.06 


I-I2 
1. 00 
1.03 
I . 12 


Bombay (adulterant) 


0.81 



* The figures in this column do not express starch, but amylo-dextrin, which like starch may be 
determined by the diastase method. 



484 



FOOD INSPECTION AND ANALYSIS. 




Fig. 

the Microscope. 

Moeller.) 



' Microscopical Structure of Mace. — Fig. 91 shows characteristics of 
mace, (i) being a cross-section through it, (2) a surface view of the 

epidermis, showing its elongated, often 
nearly rectangular cells, and (3) the large- 
celled parenchyma, in which are numerous 
oil globules. The contents of the paren- 
chyma cells are for the most part color- 
less, consisting of protein, fat, and 
granules of amylodextrin, which are shown 
at (4). At (5) are shown fragments of 
vascular tissue. 

The water-mounted powder of pure 
mace shows no highly colored fragments, 
9i-^Po^fiered Mace under \fxxt as a mass, is white or grayish, and 
X125. ( ter ^£ loose texture. Occasional pale, yel- 
lowish, lumpy masses appear, and pale- 
brown fragments of the seed coating. The amylodextrin granules 
(which are colored red-brown by solution of iodine) are very 
small. 

U. S. Standards. — Mace should contain not less than 20 nor more 
than 30% of non- volatile ether extract; nor more than 3% of total ash; 
nor more than 0.5% ash insoluble in hydrochloric acid; nor more than 
10% of crude fiber. 

Adulteration. — Turmeric and cereal starches have been detected in 
mace, but by far the most common adulterant is the so-called false, or 
wild mace, otherwise known as Bombay mace. 

The non-volatile ether extract of both Bombay and Macassar mace 
is twice as high as that of true mace, and at room temperature the fixed 
oil of Bombay mace is a thick and viscous fat, while that of true and other 
maces is a thin oil. 

The refractive indices of the fixed oils of various species of pure, as 
well as of Bombay mace, as determined by Lythgoe follow : 



SPICES. 485 

iiD at 35° C. 
Banda Mace (i) i .4848 

" " (2) 1.4747 

(3) 1-4829 

Batavia Mace (i) 1-4893 

(2) 1-4975 

Papua Mace (i) i .4816 

(2) 1.4795 

West Indian Mace (i) 1.4766 

Bombay Mace (i) 1.4615 

(2) 1-4633 

The microscope indicates at once when Bombay mace is present in 
a sample. The oil glands situated in the outer layers of Bombay mace 
are strongly colored and contain a reddish resinous substance, while the 
glands of the more interior layers have balsam-like contents of bright 
yellow color. Both the red and yellow lumps are visible in water mounts, 
but a 5% potassium hydroxide solution colors them a brilliant blood-red, 
making possible an approximate percentage* estimation of Bombay mace 
in true mace. 

Hefelmann's Test for Bombay Mace * consists in saturating a strip 
of filter-paper with an alcoholic solution of the mace, and removing the 
excess of liquid by pressure between filter-paper. On treating with a 
drop of dilute sodium or potassium hydroxide solution, a red color is 
produced in presence of the wild mace. 

Waage's Test.'f — One part of the mace is extracted with ten parts of 
alcohol, and potassium chromate solution is added to the extract. If 
Bombay mace is present, the solution becomes red, and the precipitate, 
which is at first yellow, becomes red on standing. True mace gives a 
yellow solution and precipitate, and the latter does not change greatly on 
standing. 

* Pharm. Zeit., 36, 1891, p. 122. 
t Pliarm. Centbl., 33, 1892, p. 372. 



CHAPTER XIII. 
OILS AND FATS. 

Constituents. — The oils and fats are essentially the glycerol salts or 
triglycerides of the fatty acids. Free fatty acids, lecithin (page 35), and 
sterols (cholesterol and phytosterol, page 521) are among the minor con- 
stituents. Vegetable oils owe their yellow color to carotin or related 
substances. Butter fat also contains carotin derived indirectly from feeds. 
The greenish color of certain grades of olive and other oils is due to chlor- 
ophyl. 

Mono- and di-glycerides are prepared synthetically, but do not exist 
in natural oils or fats. 

Solubilities of Oils and Fats. — The edible members of the group are 
insoluble in water, and are almost insoluble in cold 95% alcohol, though 
they are somewhat soluble in absolute alcohol. They are readily soluble 
in ether, petroleum ether, chloroform, carbon tetrachloride, various chloro- 
compounds of ethylene and ethane (especially trichloro-ethylene) , acetone, 
amyl alcohol, oil of turpentine, and carbon bisulphide. 

Fatty Acids. — Following, compiled from Lewkowitsch,* are the fatty 
acids whose glycerides occur in edible oils and fats, together with their 
melting- and boiling-points so far as these have been determined. 





ACIDS OF 


EDIBLE 


OILS AND FATS. 


Name. 


Formula. 


Melting- 
point. 


Boiling- 
point. 


Occurrence in Oils and Fats. 


Acetic Series 

Butyric 


CnH2re02 

C4H8O2 

C6H12O2 

C8H16O2 

C10H20O2 

Cl2H2402 
C14H28O2 

Cl6H32C)2 


-6.5° 

16. 5 
31 3 

43 6 
53.8 

62.6 


162.3° 
202-203 
236-237 
268-270 

176 

196.5 

215 


Butter 


Caproic 

Caprylic 


Butter, cocoanut, palm nut. 
Butter, cocoanut, palm nut. 
Butter, cocoanut, palm nut. 
Cocoanut, palm nut. 
Cocoanut, palm nut, sesame, 

butter. 
Nearly all oils and fats. 


Capric 


Laurie 


Myristic 


Palmitic 





* Chemical Technology and Analysis of Oils, Fats, and Waxes, sth ed., London, I, 1913, 
p. 348. 

483 



OILS AND FATS. 



487 



Name. 



Stearic 

Arachidic 

Behenic 

Lignoceric 

Oleic Series 

Hypogaeic 

Oleic 

Iso-oleic 

Rapic 

Erucic 

Linolic Series 

Linolic 

Linolenic series 

Linolenic 

Clupanodonic Series. 

Clupanodonic . . . . 



Formula. 



C18H36O2 

C20H40O2 

C22H44O2 

C24H48O2 

CnH27j— 2O2 

C16H30O2 

C18H34O2 

C18H34O2 

C18H34O2 

C22H42O2 

^nH2n — 4O2 

C18H32O2 



C0H20— eOa 
C18H30O2 
CnH2o— 8O2 

C18H28O2 



Melting- 


Boiling- 


pomt. 


pomt. 


69 -3° 


232.5 


77 




83-84 




81 




33 


236 


14 


232.5 


44-45 




33-34 


264 


under —18 





Occurrence in Oils and Fats. 

Fats, most oils, except olive and 

maize. 
Peanut, butter (trace), rape, 

cocoa. 

Peanut. 

Peanut. 

Nearly all fats and oils. 

Rape, mustard. 
Rape, mustard. 

Linseed, olive, cottonseed, pea- 
nut, sesame, maize, cocoa, pop- 
py seed, soy bean, sunflower. 

Linseed, poppy seed, soy bean. 

Whale, cod-liver, fish. 



Saponification of Fats and Oils. — By this term is meant the decom- 
position of the glycerides composing the fats or oils, whereby the tri- 
atomic alcohol glycerol and the fatty acids or their alkali soaps are sep- 
arated. The saponification process is commonly applied in carrying out 
many determinations of value on fats and oils, such as those of the soluble 
and insoluble fatty acids, the Reichert value, etc. As commonly carried 
out, the tri-glycerides are first split up into glycerol and the soluble soaps 
of the fatty acids by the action of caustic alkali, usually in solution in 
alcohol. This part of the process in the case of a given oil, composed, 
for example, of stearin, olein, and palmitin, is illustrated as follows: 

(1) C3H5(Ci8H3502)3+3KOH = C3H5(OH)3+3K(Ci8H3502) 

Stearin or Glycerol Potassium 

triglyceryl stearate 

stearate 

(2) C3H.5(Ci6H3i02)3+3KOH = C3H5(OH)3+3K(C,6H3i02) 

Palmitin or Potassium 

triglyceryl p»lmitate 

palmitate 



(3) C.3H,5(C,sn3302)+3KOH =C3H5(OH)3+3K(Ci8H3302) 

Olein or tri- J- Potassium 

glyceryl oleate oleate 



488 FOOD INSPECTION AND ANALYSIS. 

These " soaps," or potassium salts of the fatty acids, are further de- 
composed by the action of sulphuric acid into the free fatty acids and 
potassium sulphate, in the case of potassium stearate, as follows : 

2K(Ci8H3502)+H2S04 = K2S04+2H(CikH3502) 

Potassium stearate Stearic acid 

The result obtained in the determination of saponification number — 
the number of milligrams of potassium hydroxide required to saponify 
I gram of fat — is inversely proportional to the average molecular weight 
of the glycerides present. 

Hydrogenation of Oils. — Recently the hardening of oils by hydro- 
genation, employing nickel (or less often platinum or palladium) as a 
catalyst, has become of commercial importance. By this process olein 
and other unsaturated glycerides are more or less completely converted 
into stearin as is shown by the lowering of the iodine number and the 
change of the physical constants. Not only are vegetable oils hardened 
by hydrogenation but also whale oil and other fish oils which may be 
transformed from inedible products into bland and tasteless fats. Hardened 
oils are used in lard substitutes in place of natural stearin. 

Various oxides and salts of nickel have been used in place of the metal 
in hydrogenation, but the actual catalyst in all such cases, although for 
some years a matter of dispute, has been shown without question to be 
the metal. 

The treatment, unless slight, renders useless the Halphen test for cotton- 
seed oil and the hexabromide test for fish oils, but does not usually inter- 
fere with the Baudouin test for sesame oil. Bomer* finds that neither 
cholesterol nor phytosterol is changed. 

The table of results by Bomer * on page 489 shows the effects of 
hydrogenation on the chemical and physical constants of certain oils. 

ANALYSIS OF EDIBLE OILS AND FATS. 

Judgment of Purity of fats and oils presents numerous difficulties 
owing partly to the variation of the physical and chemical constants. 
Among the influences affecting the constants are, in the case of vegetable 
oils, the large number of varieties and species of fruits or seeds from which 
each oil in different localities is obtained, in the case of animal fats, the 
breed and feed, and in both cases the method of refining, age, and con- 
ditions of storage. Hydrogenation has added further to the difficulties. 

* Zeits. Unters. Nahr. Genussm., 24, 191 2, p. 107. 



OILS AND FATS. 489 

EFFECTS OF HYDROGENATION ON THE CONSTANTS OF OILS. 





Hardness. 


.Color. 


Melting 

Point. 

Deg. C. 


Solidi- 
fying 
Point. 
Deg. C. 


Refract- 

ometer 

Reading 

at 40° C. 


Acid 

Number 

(Mgs. 

KOH 

per 

gram). 


Saponi- 
fication 
Number. 


Iodine 

Number. 


Peanut oil 

Natural 


Fluid 

Soft 

Medium * 

Hardf 

Hardt 

Medium * 

Soft 
Medium * 

Hard t 


Yellow 
White 
White 
White 

White 

Yellow 

White 
White 

Yellow 


44.2 
46.1 
53-5 

62.1 

38.5 

25.6 
44-5 

45-4 


30.2 
32.1 
38.8 

45-3 
25 4 

20.4 
27.7 

33-7 


56.8 
52.3 
50-5 
49 

38. 4t 

53-8 

37-4 
35-9 

49.1 


I.I 

1-3 
0.9 
1.2 

4-7 
0.6 

0-3 
0.4 

1 .1 


191 .1 
188.3 

188.4 
189.0 

188.9 
19s 7 

255-6 
254-1 

193.0 


84.4 
56.5 
54-1 
42.2 

25-4 

69,7 

11.8 

I.O 

46.8 


Hardened 

Sesame oil 

Hardened 

Cottonseed oil 

Hardened 

Cocoanut oil 

Natural 


Hardened 

Whale oil 
Hardened 



•*■ 



* Consistence of lard. 



t Consistence of tallow. 



t Determined at 50° C. 



It is often difficult to name the adulterant or estimate the "xtent of 
adulteration. In some cases a large number of tests must be made before 
one can intelligently form an opinion. It should be borne in mind that 
skilful manufacturers may adulterate the edible oils and fats with mix- 
tures intended to confuse the chemist, and yield on analysis constants 
that are entirely misleading. Information may often be gained by care- 
fully noting the color, taste, odor, and appearance of the sample. 

Rancidity should not be confounded with acidity, although rancid oils 
usually are high in acids. Lewkowitsch holds that fatty acids are liberated 
by the action of moisture in the presence of enzymes. If in addition the 
oil is exposed to air and light, the fatty acids are acted on, causing rancidity, 
which is detected by taste and smell, although chemically little understood. 
As a rule rancidity develops more readily in liquid oils in which olein 
predominates than in solid fats. To avoid changes samples should be 
kept in a dark, cool place in tight containers. 

Filtering, Measuring, and Weighing of Fats. — A steam- or hot- water- 
jacketed funnel as represented in Fig. 92 is convenient for filtering fats, 
or, in the absence of this contrivance for keeping the fat in a molten con- 
dition, a hot funnel may be employed, the filtering being best conducted 
in a warm closet or oven. 

Portions of the fat for the various determinations may be measured 
off with a pipette while still hot, or, after cooling (over ice if necessary), 
the desired amounts may be removed in the solid state. 



490 



FOOD INSPECTION AND ANALYSIS. 



Specific Gravity. — The specific gravity of liquid oils is most con- 
veniently taken either at room temperature or at 15.5°, being always 
best referred to the latter. Either the hydrometer, Westphal balance, 
Sprengel tube, or pycnometer is employed, according to the degree of 
accuracy required. If taken at any other temperature than 15.5°, say 




Fig. 92. — Jacketed Funnel for Hot Filtration, 
at room temperature, T, the specific gravity may be computed at 15.5° 

by the formula /-, , t^z-t- \ ± 

^ G=G' + KiT-is.s),* 

in which G is the specific gravity at 15.5°, G' the specific gravity at T°, 
and K a factor varying with the different oils as follows: 

FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Oil. 


Correction 
for 1° C. 


Observer. 


Cod-liver oil 


0.000646 
.000658 
.000629 
.000655 
.000620 
.000624 
.000629 


A. H. Allen 
C. M. WetheriU 
C. M. Stillvvell 
A. H. AUen 

<< 










Sesame oil 







* Allen, Com. Org. Anal., 4 Ed.; Vol. II, p. 49- 



OILS AND FATS. 



491 



Unless the most accurate work is necessary, it is sufficient to assume 
in all cases A" ---0.00064, in which case the formula becomes G=G' + 
o.oco64(r-i5.5). 

In the case of solid fats, it is most convenient to take the specific 
gravity of the melted fat. This may be done at any temperature above 
the melting-point by either of the instruments above described, or at the 
temperature of boiling water by the Westphal balance or pycnometer. 
The figures thus obtained may be compared with those for water de- 
termined in the same apparatus, either at the same temperature or at 15.5°. 

When the pycnometer is used, it is immersed in a water-bath, the 
temperature of which is well above the melting-point of the fat, say 35° 
or 40° or 100°. While still immersed nearly to the neck, it is carefully 
filled with the melted fat and kept in the bath till the fat has acquired 
the same temperature, usually about 15 minutes. If the pycnometer is 
provided with a thermometer stopper, this will serve to indicate the tem- 
perature; otherwise a separate thermometer is inserted in the bath. 
The pycnometer is then removed, cleaned, dried, and cooled to the room 
temperature, at which it is weighed. The factors employed in the above 
formula for calculation of specific gravity of solid fats at 15.5° are as follows: 

FACTORS FOR CALCULATING SPECIFIC GRAVITY. 



Fat. 


Correction 
for 1° C. 


Cocoa butter 


0.000717 
.000673 
. 000650 
.000617 
. 000674 
. 000642 
.000657 


Tallow 


Lard 


Butter fat 


Cocoanut stearin 


Cocoanut oil 


Palm nut oil 





Either the Westphal balance or the hydrometer may be used directly 
on the melted fat, carefully recording the temperature and calculating 
as above. 

For making the determination with the Westphal balance at the 
temperature of boiling water, the melted fat is contained in a vessel im- 
mersed in a boiling water-bath, and kept sufficiently long to acquire that 
temperature, which is carefully noted. 

Calculation of Proportions of Two Known Oils in Mixture.* — This 
may be roughly accomplished from the specific gravity of the mixture 
and of the oils known to compose it. 

* Villiers et Collin, Les Substances Alimentaires, Paris, 1900, p. 646. 



492 



FOOD INSPECTION AND ANALYSIS. 



Then 



Let G = specific gravity of mixture, 
D and D' = specific gravity of the two oils, 
and X = % oil of specific gravity D. 
ioo{G-D') 
D-D' ' 

SPECIFIC GRAVITY OF EDIBLE OILS AND FATS. 



Oil. 



Rape oil 

Olive oil 

Lard oil 

Mustard oil. . . 
Sesame oil. . . . 
Peanut oil ... . 
Cottonseed oil 
Sunflower oil. . 

Maize oil 

Poppyseed oil. 

Soy oil 

Linseed oil 



Specific Gravity, 
15-5° 
15. 5°' 



0.913-0. 917 
0.915-0. 918 
0.915-0. 918 
0.914-0. 919 
0.921-0.924 
0.917-0.926 
0.922-0.926 
0.924-0.926 
0.921-0.927 
0.924-0.927 
0.922-0.928 
0.931-0. 941 



Fat. 


Specific Gravity, 
100° 

15.5°' 


Mutton tallow 


0.858-0.860 

0.858 
0.858-0.862 
. 860-0 . 863 
0.860-0.863 
0.859-0.864 
0.864-0.868 

0.870 

0.870 
0.865-0.870 
0.859-0.873 
0.863-0.874 


Cacao butter 


Oleo stearin 


Beef tallow 


Oleo oil ... •. 


Lard 


Cottonseed stearin 


Cocoanut stearin 


Palm kernel stearin 


Butter fat 


Palm kernel oil 


Cocoanut oil 





Determination of Viscosity in the case of edible oils, is of less im- 
portance than in the case of lubricating oils, and gives little insight into the 
nature or purity of the sample. Its application in the detection of oleo- 
margarine in butter is discussed by Lewkowitsch.* Descriptions of viscosi- 
meters are given by the same author. 



Loc. cit., p. 348. 



OILS AND FATS. 



493 



Determination of Refractive Index, and the reading on the arbitrary 
scale of the butyro-refractometcr, express in two different and interchange- 
able terms the refraction value, a useful and easily determined constant of 
fats and oils. 

For the routine examination of fats and oils the butyro-refractometer 
is more convenient than the Abbe refractometer, and the readings obtained 
by the former instrument are less cumbersome than refractive indices. 

These instruments and details with regard to their manipulation are 
described in Chapter VI. 

The readings on the scale of the butyro-refractometer may be readily 
transformed into refractive indices and vice versa by table or by means of 
the Leach and Lythgoe slide rule (page 93). Lythgoe's * table on 
pages 494 and 495 is useful as showing readings on the butyro-refractometer 
of edible oils and fats at various temperatures. 



REFRACTION OF EDIBLE OILS AND FATS. 



Oil. 




Refractive Index, 25°. 



Lard oil 

Olive oil 

Peanut oil ... . 
Cottonseed oil . 

Rape oil 

Mustard oil . . . 
Sesame oil ... . 

Maize oil 

Sunflower oil . . 

Soy oil 

Poppy seed oil . 
Linseed oil 



4620-1 . 4660 
4659-1.4680 
4691-1.4707 
4698-1.4723 
4708-1.4723 
4688-1.4729 
4710-1.4729 
4729-1.4734 

I • 4735 
4729-1,4742 
4723-1.4754 
4789-1.4824 



Fat. 


Butyro Scale, 40°. 


Refractive Index, 40°. 


Cocoanut stearin 


33-36 

36-39 
40.5-46* 
40-48 
46-48 
46-49 
49 

47-50 X; 
48.5-52.5 




Cocoanut oil 


I. 4474-1. 4495 


Palm kernel stearin 


Palm kernel oil 


I. 4495-1. 45 I 7 
1.4527-1.4566! 
I. 45 24-1. 4580 
1.4566-1.4580 
I . 4566-1 . 4586 

1.4586 
I. 45 73-1. 4593 § 
1.4583-1.4609 


Butter fat 


Oleo stearin 


Cacao butter 


Beef tallow 


Mutton tallow 


Oleo oil 


Lard 


Cottonseed stearin 







.7-54.2 at 25°. 1 1.4582-1.4621 at 25° 



X 55.2-58.2 at 25'= 



§ 1.4627-1.4647 at 25° 



Tech. Quart., 16, 1903, p. 222. 



494 



FOOD INSPECTION AND ANALYSIS. 



CALCULATED READINGS ON BUTYRO-REFRACTOMETER OF EDIBLE 

OILS AND FATS. 



Temp. 
C. 



45-0 

44-5 
44.0 

4S-5 
43-0 
42.5 

42.0 

41-S 
41.0 

40-5 
40.0 

39-5 
39-0 
38-5 
38.0 

37-5 

37-0 
36.5 
36.0 

35-5 
35-0 

34-5 
34-0 
33-5 
33-0 
32 5 

32.0 

31-S 
31.0 

30-5 
30.0 

29-5 
29.0 
28.5 
28.0 

27-5 

27.0 
26.5 
26.0 

25-5 
25.0 



Cocoanut 
Oil. 



31- 

31 
32 
32 
32 
52 

35 
33 
33 
34 
34 

34 
34 
35 
35 
35 

35 
36 
36 
36 
36 

37 
37 
37 
37 
38 

38 
38 
38 
39 
39 

39 
40 
40 
40 
40 

41 
41 
41 
41 
42 



Butter.* 



41 

41 
42 
42 
42 
42 

43 
43 

43 
43 
44 

44 
44 
45 
45 
45 

45 
46 
46 
46 

47 

47 

47 
47 



B ef 

Stearin. 



41.9 

42.2 

42.4 
42.6 
42.9 

43-2 

43-5 
43-7 
44.0 
44.2 
44-5 



Cacao 
Butter. 



43-7 

44.0 
44-2 

44-5 
44-8 

45-0 



45-3 
45-6 

45-9 
46. 1 
46.4 

46.6 
46.8 
47-1 
47-4 
47-6 

47-9 
48.2 

48-5 
48.7 
49.0 



B f 
Talli)W. 



44-1 

44-3 
44.6 
44-8 
45-1 

45-4 

45-6 
45-8 
46. 1 

46-3 
46.6 

46.8 
47-1 
47-4 
.17.6 

47-8 



48. 
48. 
48. 
48- 
49- 



Lard 

StLarin. 



44-9 

45-1 

45-5 
45-7 
46.0 

46.3 

46.5 
46.8 
47.0 

47-3 
47-6 



47- 
48. 
48. 
48. 
48. 



49-2 
49.4 

49-7 
50.0 
50.2 



Beef 

Oleo. 



45-0 



45- 
45- 
45- 
46. 
46. 

46. 
47' 
47- 
47- 
47- 

48. 
48. 
48. 
48. 
49- 

49. 

49. 

50- 
50. 

50- 

50- 
51- 
5T- 
51- 

52- 

52. 
52- 
52. 

53- 
S3- 



53- 
54- 
54- 
54- 

55- 

55- 

5: 

65. 

66. 



Lard.t 



•3 


48. 


.6 


48. 


-9 


49- 


). r 


49- 


>-4 


49- 


>-7 


49- 


.0 


50. 


-3 


■;o. 


.6 


50- 


.8 


51- 


.1 


51- 


-4 


51- 


-7 


51- 


-9 


52- 


.2 


52- 


.5 


52- 


.8 


53- 


.0 


53- 


-3 


53- 


.6 


53- 


-9 


54- 


.2 


54- 


. t; 


54- 


-7 


55- 


.0 


55- 


-3 


55- 


.6 


55 -< 


.8 


=;6. 


.1 


S6.. 


-4 


56- 


- 7 


57-c 


-9 


57-. 


.1 


57-' 


-4 


57-J 


-7 


58- 


.0 


58- 


.2 


58. 


- ■> 


59 -c 


.8 


59-, 


. I 


59-< 



* Butter readings by Zeiss. 
t Lard readings by Hefelmarm, 



OILS AND FATS. 



495 









CALCU 


LATED 


READINGS— {ContinMcT). 






Temp. 
C. 


Olive 
Oil. 


Peanut 
OU. 


Cotton- 
seed 
Oil. 


Rape- 
seed 
Oil. 


Sesame 
Oil. 


Yellow 

Mustard 

Oil. 


Black 

Mustard 

Oil. 


Sun- 
flower 
Oil. 


Corn 
Oil. 


Poppy- 
seed 
Oil. 


35-0 


57-0 


59-8 


61.8 


62.1 


62.3 


63.0 


64.2 


64-5 


65.0 


-5-5 


34-5 


57-2 


60.0 


62.1 


62.4 


62.5 


63-3 


64.5 


64.8 


65-3 


6s. 8 


34 o 


57-4 


60.3 


62.3 


62.7 


62.8 


63.6 


64.8 


65-1 


65.6 


66.1 


33-5 


57-7 


60.6 


62. 5 


63.0 


63.1 


63-9 


65.1 


65-4 


65-9 


66.4 


33-0 


58.0 


60.9 


62.8 


63-3 


63-4 


64.1 


65-3 


65-7 


66.2 


66.7 


3^-5 


58-3 


61. 1 


63.0 


63.6 


63-7 


64.4 


65.6 


66.0 


66.5 


67.0 


32.0 


58.5 


61.4 


63.2 


63.8 


64.0 


64.7 


65-9 


66.3 


66.8 


67-3 


31-5 


59-0 


61.7 


63.6 


64.1 


64-3 


65.0 


66.2 


66.6 


67.1 


67.6 


31.0 


59-2 


62.0 


64.0 


64.4 


64.6 


65-3 


66.5 


66.9 


67.4 


67.9 


30-5 


59-5 


62.2 


64.2 


64.7 


64.9 


65.6 


66.8 


67.2 


67-7 


68.2 


30.0 


59-9 


62.5 


64-5 


65.0 


65.1 


65.8 


67.0 


67-5 


68.0 


68.5 


29-5 


60.1 


62.8 


64.9 


65-3 


65-4 


66.1 


67-3 


47-7 


68.2 


68.7 


29.0 


60.3 


63.1 


65.1 


65.6 


65-7 


66.4 


67.6 


68.0 


68.5 


69.0 


28.5 


60.6 


63-3 


65-3 


65-9 


66.0 


66.7 


67.9 


68.3 


68.8 


69-3 


28.0 


60.9 


63.6 


65-7 


66.1 


66.2 


66.9 


68.1 


68.6 


69.1 


69.6 


27-5 


61. 1 


63-9 


66.0 


66.4 


66.5 


67.2 


68.4 


68.9 


69.4 


69.9 


27.0 


61-S 


64.2 


66.5 


66.7 


66.8 


67-5 


68.7 


69.2 


69.7 


70.2 


26.5 


62.0 


64-4 


67.0 


67.0 


67.1 


67.8 


69.0 


69-5 


70.0 


70-S 


26.0 


62.2 


64-7 


67-3 


67-3 


67.0 


68.0 


69.2 


69.8 


70-3 


70.8 


25-5 


62.4 


65.0 


67-5 


67.6 


67.7 


68.3 


69-5 


70.1 


70.6 


71. 1 


25.0 


63.0 


65-3 


67.9 


67.8 


67.9 


68.6 


69.8 


70.4 


70.9 


71-4 


24-5 


63-3 


65-5 


68.2 


68.1 


68.2 


68.9 


70.1 


70.7 


71.2 


71.7 


24.0 


63.6 


65.8 


68.'? 


68.4 


68.5 


69.2 


70.4 


71.0 


71-5 


72.0 


23-5 


63-9 


66.1 


68.8 


68.7 


68.8 


69-5 


70.7 


71-3 


71.8 


72-3 


23.0 


64.2 


66.4 


69.1 


69.0 


69.1 


69.7 


70.9 


71.6 


72.1 


72.6 


22.5 


64-5 


66.6 


69.4 


69-3 


69.4 


70.0 


71.2 


71.9 


72.4 


72-9 


22.0 


64.8 


66.9 


69.7 


69.7 


69.7 


70-3 


71-5 


72.2 


72.7 


73-2 


21-5 


65.1 


67.1 


70.0 


70.0 


70.0 


70.6 


71.8 


72-5 


73-0 


73-5 


21.0 


65-4 


67.4 


70-3 


70.3 


70.3 


70.9 


72.1 


72.8 


73-3 


73-8 


20.5 


65-7 


67.7 


70.6 


70.6 


70-5 


71.2 


72.4 


73-1 


73-6 


74-1 


20.0 


66.0 


68.0 


70.9 


70.8 


70.8 


71.4 


72.6 


73-4 


73-9 


74-4 


19-5 


66.3 


68.2 


71.2 


71. 1 


71. 1 


71.7 


72-9 


73-6 


74-1 


74-6 


19-0 


66.6 


68. c; 


71-5 


71.4 


71.4 


72.0 


73-2 


73-9 


74-4 


74-9 


18.5 


66.9 


68.8 


71.8 


71.7 


71.7 


72-3 


73-5 


74-2 


74-7 


75-2 


18.0 


67.2 


69.1 


72.1 


72.0 


72.0 


72.6 


73-8 


74-5 


75-0 


75-5 


17-5 


67-5 


69-3 


72-4 


72-3 


72-3 


72.9 


74-1 


74-8 


75-3 


75-8 


17.0 


67.8 


69.6 


72.7 


72.6 


72-5 


73-1 


74-3 


75-1 


75-6 


76.1 


16.5 


68.1 


69.9 


73-0 


72.9 


72.8 


73-4 


74-6 


75-4 


75-9 


76-4 


16.0 


68.4 


70.2 


73-3 


73-2 


73-1 


73-7 


74-9 


75-7 


76.2 


76-7 


15-5 


68.7 


70-5 


73-6 


73-5 


73-4 


74.0 


75-2 


76.0 


76-S 


77.0 


15.0 


68.9 


70.8 


73-8 


73-8 


73-7 


74-3 


75-5 


76.3 


76.8 


77-3 



496 



FOOD INSPECTION AND ANALYSIS. 



Determination of Melting-point and Solidifying Point. — A piece of 
small glass tubing is drawn out to a capillary open at both ends, and 
this is inserted into a beaker of the fat, melted at a temperature slightly 
above its fusing-point. A portion of the melted fat being drawn up into 
the capillary, the latter is removed and the fat allowed to solidify spon- 
taneously. After an interval of not less than twelve hours, the capillary 
is attached by a rubber band to the stem of a delicate thermometer (pref- 
erably capable of being read to tenths of a degree) , the portion of solidified 
fat being opposite the thermometer bulb. A test-tube containing water 
is held in the neck of a flask in such a manner as to be immersed in 
water contained in the flask, as shown in Fig. 93, the flask being held 
on the ring of a stand, with wire gauge interposed between flask and 
flame. The thermometer with attached capillary is then held immersed 





Fig. 93. Fig. 94. 

Fig. 93. — Apparatus for Determining Melting-point. Capillary tube with enclosed 
fat shown on the right, enlarged. 

Fig. 94.— Reichert Flask with Card Inserted for Quick Evaporation. 

in the water of the test-tube and below the level of the water in the flask, 
as shown. The water in the flask is then heated very gradually, so that 
the rise of temperature as shown by the thermometer does not exceed 
0.5° C. per minute, the exact temperature at which fusion of the fat occurs 
being recorded as the melting-point. 



OILS AND FATS. 



497 



The flame is then removed, and the temperature at which the fat 
solidifies is noted as the solidifying-point. 



MELTING AND SOLIDIFYING-POINTS OF EDIBLE OILS AND FATS. 



Oil. 


Melting-point. 


Solidifying-point. 


Linseed oil 




-25° 
— 18 


Poppy seed oil 




Sunflower oil 




— 19 to —16 
-17 to -15 


Mustard oil 




Maize oil 




Soy oil 




-15 to - 8 

— 5 too 

— 6 to — 4 
oto -f 3 

— 10 to +10 

— 6 to +10 


Cottonseed oil 




Sesame oil 




Peanut oil 




Rape oil 




Olive oil 




Lard oil 









Fat. 


Melting-point. 


Solidifying-point. 


Cocoanut oil 


20-28° 
28-36 

29 
23-30 
28-35 
31-32 
30-39 
36-46 
26-40 
42-49 
44-49 
44-54 


14-23° 
19-24 


Butter fat 


Cocoanut stearin 


Palm kernel oil 


20-27 

21-27 

28 


Cacao butter 


Palm kernel stearin 


Oleo oil 




Lard 


27-30 
16-33 
27-35 
32-41 
40-50 


Cottonseed stearin 


Beef tallow 


Mutton tallow 


Oleo stearin 





The mean of two or three determinations is usually taken as the true 
melting and solidifying-points. 

Reichert-Meissl Process for Volatile Fatty Acids. — This process 
has undergone various modifications from time to time. Reichert origi- 
nally used 2.5 grams of fat, but Meissl, who improved the process, used 
5 grams, so that the Reichert-Meissl number is now expressed on the 
basis of 5 grams of fat. The method is conveniently carried out as 
follows : 

Five grams of the fat are transferred to a dry, clean Erlenmeyer flask 
of about 300 cc. capacity, 10 cc. of 95% alcohol are added, and 2 cc. of 



498 



' FOOD INSPECTION AND ANALYSIS. 



sodium hydroxide solution (prepared by dissolving loo grams of sodium 
hydroxide in loo cc, of water). The flask with its contents is then heated 
on a water-bath with a funnel in the neck, which satisfactorily replaces 
the return-flow condenser originally prescribed. The heating is con- 
tinued with occasional shaking till saponification is complete. This 




Fig. 05. — Apparatus for Reichert-Meissl and Polenske Distillation. 



Stage of the process is indicated by the appearance of the solution, which 
is then perfectly clear and free from fat globules. 

The condenser-funnel being removed, the contents of the flask are 
next evaporated by continued heating over the bath to dryness. This 
may be hastened by inserting a card in the neck of the flask, as shown in 
Fig. 94, thus starting a circulatory movement to the air through the flask. 

The dry soap thus formed is then dissolved by warming on the water- 
bath with i.:?q cc. of added water, shaking the flask occasionally. After 



OILS AND FATS. 499 

cooling, 5 cc. of dilute sulphuric acid (200 parts sulphuric acid in i liter 
of water) are added, and the fatty acid emulsion formed is melted by 
heating the flask on the water -bath, the flask being corked during the 
heating. The fatty acids are completely mehed when they form an oily 
layer on the surface of the solution. 

Scraps of pumice stone joined by platinum wires are next placed in 
the flask to prevent bumping, and the flask is properly connected with 
the condenser for distilling, as shown in Fig. 95. A flask graduated at 
no cc. is used as a receiver, the funnel placed therein being provided 
with a loose tuft of absorbent cotton to serve as a filter. The distilla- 
tion is conducted by so grading the heat that the receiving flask is 
filled with the distillate in about thirty minutes. 

Finally the entire distillate is titrated with decinormal sodium hydrox- 
ide, using 0.5 cc. of a solution of phenolphthalein as an indicator. The 
number of cubic centimeters of decinormal alkali required to neutralize 
the acidity of the distillate from 5 grams of the fat in the manner described 
expresses what is known as the Reichert-Meissl number. 

Lejjmann and Beam's Modification.'^ — Five grams of the fat placed in 
the flask are treated with 20 cc. of a solution of soda in glycerin (20 cc. 
of a 50% solution of sodium hydroxide in 180 cc. of glycerin), heating the 
flask till the contents are completely saponified. The solution becomes 
perfectly clear, showing complete saponification in about five minutes, 
after which 135 cc. of water are added to the clear soap solution, at first 
drop by drop to prevent foaming; 5 cc. of the dilute sulphuric acid are 
then added, and the distillation conducted at once without first melting 
the fatty acids. 

Polenske Number.! — This number represents the volatile fatty acids 
insoluble in water, and is of value in detecting cocoanut and palm kernel 
oils in butter and other fats. The details of apparatus and manipulation 
here described should be closely adhered to in order to secure comparable 
results. The Reichert-Meissl, Polenske, and Jensen- Kirschner numbers 
may be determined in one weighed portion of the fat. The method of 
saponification is that devised by Leffmann and Beam. 

Place 5 grams of the clear filtered fat in a 300-cc. Jena flask, add 20 
grams of glycerine and 2 cc. of a 50% solution of sodium hydroxide. 
Heat the flask on a wire gauze until the contents are completely saponified, 
which requires about 5 minutes, and is indicated by the clearing up of the 
liquid. While still hot add 90 cc. of boiled water, at first drop by drop 

* Analyst 16, 1891, p. 153. 

t Polenske, Zeits. Unters. Nahr. Genussm., 7, 1904, p. 274. Fritsche, ibid., p. 193. 



500 FOOD INSPECTION AND ANALYSIS. 

to prevent foaming, and shake until the soap is dissolved. The solution 
should be completely clear and almost colorless. Rancid or oxidized 
fats that yield a brown soap solution should not be examined. 

To the soap solution, warmed to 50°, add 50 cc. of dilute sulphuric 
acid (25 cc. : i liter) and 0.5 gram of granulated pumice stone with grains 
I mm. in diameter, then connect with the distilling apparatus shown in 
Fig. 95. Distil over a 0.5-mm. mesh copper gauze,* using a Bunsen 
flame so regulated as to give a distillate of no cc. in 19-20 minutes, and 
a stream of water that will cool the distillate to about 20-23°. The room 
should have a temperature of about 18-22°. As soon as no cc. have 
come over, replace the flask by a 25-cc. measuring cylinder. 

Without mixing the distillate place the flask for 10 minutes in water 
at 15°, so that the iio-cc. mark is about 3 cm. below the surface of the 
water. After the first 5 minutes, gently "move the neck of the flask in 
the water so that the fatty acids floating on the surface come in contact 
with the glass, noting at the end of 10 minutes the condition of these 
acids. If the butter is pure, the floating acids are either solid or form a 
half solid turbid mass, according as the Reichert-Meissl number is high 
or low; if it is adulterated with 10% or more of cocoanut oil, they form 
transparent oil drops. Stopper the iio-cc. flask, mix by inverting 4 or 5 
times, avoiding violent shaking, filter through an 8-cm. dry filter fitted close 
to the funnel, titrate 100 cc. of the liquid with N/io barium hydroxide 
solution, and multiply by i.i, thus obtaining the Reichert-Meissl number. 

After the last drop of distillate has passed through the filter, wash 
with three 15-cc. portions of water, each of which has previously been 
used to rinse the condenser tube, the measuring cylinder, and the iio-cc. 
flask. Then repeat this treatment, using 15-cc. portions of neutral 90% 
alcohol. Titrate the united alcoholic washings with tenth-normal barium 
hydroxide solution, using phenolphthalein as indicator. The number of 
cc. required is the Polenske number. 

The following results illustrate the value of the method: 

Reichert-Meissl Polenske 

Number. Number. 

31 samples of butter (Polenske) 23 . 3-30. i i . 5-3.0 

4 samples of cocoanut oil (Polenske). 6.8-7.7 16. 8-17. 8 

Oleomargarine (Arnold) 0.5 o. 53 

Lard (Arnold) 0.35 0.5 

Tallow (.\rnold) o. 55 o. 56 

* Lewkowitsch recommends a circular piece of asbestos 12 cm. in diameter with a hole 
in the center 5 cm. in diameter and warns against overheating. He was unable to secure 
uniform heating with gauze. 



OILS AND FATS. 501 

Jensen-Kirschner Number.* — This number (" Kirschner value "), 
which is a measure of the butyric acid content, is recommended by Bolton 
and Revis f as the only available means of detecting butter in oleomargarine 
containing cocoanut oil. They give tentatively Jensen-Kirschner num- 
bers 20-26 for butter as corresponding to Polenske numbers 1.6-3.2, 
also Jensen-Kirschner numbers 1.6-1.9 for cocoanut oil and i.i for palm 
oil. 

Add to the 100 cc. of distillate, neutralized for the determination of the 
Reichert-Meissl number (page 500), 0.5 gram of powdered silver sulphate, 
allow to stand for an hour with occasional shaking, filter, pipette 100 cc. 
of the filtrate into a distillation flask, add 35 cc. of water, 10 cc. of 2,5% 
sulphuric acid, and a long piece of aluminum wire, then distil as in the 
Reichert-Meissl-Polenske method, collecting no cc. of distillate in 20 
minutes. Titrate 100 cc, correct for a blank determination, and cal- 
culate the Jensen-Kirschner number by the following formula: 

i2iA"(ioo + F) 
10,000 

in which Z = cc. of N/io alkali used in the Jensen-Kirschner titration, 
corrected for blanks, and Y the cc. of N/io alkali used in the Reichert- 
Meissl titration. 

Determination of Soluble and Insoluble Fatty Acids. — Jones Method. t 
— Soluble Acids. — Five grams are weighed out and transferred to an 
Erlenmeyer flask of the same size and in the same manner as that used 
for the Reichert-Meissl process. Fifty cc. of alcoholic potash solution 
are added (40 grams of potassium hydroxide in i liter of 95% redistilled 
alcohol) and the flask, provided with a return-flow condenser, is heated 
on the water-bath till saponification is complete, as evidenced by the clear 
solution free from fat globules. The alcoholic solution of potash is pref- 
erably measured from a pipette, from which it is allowed to drain for a 
noted interval of time, say thirty seconds. 

After complete saponification, the condenser is removed and the 
alcohol is evaporated by further heating. One or more blanks are pre- 
pared at the same time, using the same 50-cc. pipette for measuring, and 



* Zeits. Unters. Nahr. Genussm., 9, 1905, p. 65. 

t Analyst, 36, 191 1, p. 333; 37, 1912, p. 183. Fatty Foods, Phila., 1913, p. 120. 

t Analyst, 3, 1878, p. 19. 



502 FOOD INSPECTION AND ANALYSIS. 

applying the same time limit for draining the pipette. The blanks are 
first titrated, after evaporation, with half-normal hydrochloric acid, 
using phenolphthalein as an indicator. Then add to the flask contain- 
ing the fatty acids i cc. more of the half-normal acid than is found neces- 
sary to neutralize the alkali in the blanks, after which heat the flask again 
with a funnel in the neck till the fatty acids have completely separated 
in a layer on top of the solution. Then cool the flask in ice water 
till the fatty acids are solidified, after which decant the liquid portion 
through a filter, previously dried in the oven and weighed, into a liter 
flask, keeping the solid mass of fatty acids intact. Next add 200 or 300 
cc. of hot water to the flask containing the fatty acids, and again melt 
over the water-bath till they collect as before on top, having again inserted 
the funnel to act as a condenser, and occasionally shaking the contents 
of the flask during heating. Cool as before in ice water, after which 
again decant the liquid from the solid mass through the same filter into 
the liter flask. Repeat this process of washing, melting, cooling, and 
decanting three times, receiving all the wash water through the same 
filter in the same flask. Make up the washings with water to the liter 
mark, and, after mixing, two portions of 100 cc. each are titrated with 
tenth-normal sodium hydroxide, using phenolphthalein for an indicator. 
Each reading is multiplied by ten to represent the total volume, and the 
figure thus obtained represents the number of cubic centimeters of tenth- 
normal alkali necessary to neutralize the acidity of the soluble fatty acids, 
together with the excess of half-normal acid used, amounting to i cc. 
This I cc. of half-normal acid corresponds to 5 cc. of tenth-normal alkali, 
hence 5 cc. are to be deducted from the total number of cubic centimeters 
required for the titration, the corrected figure thus obtained being multi- 
plied by the factor 0.0088, which gives the weight of soluble fat acids in 
the 5 grams of the sample, calculated as butyric acid. 

Hehner Method."^ — Insoluble Acids. — Transfer the fatty acids left in 
a cake in the flask from the separation of the soluble acids, to a weighed 
glass evaporating dish, using strong alcohol to wash them out thoroughly. 
Dry the filter used in the separation, transfer it to an Erlenmeyer flask, 
and thoroughly wash it with strong alcohol, transferring all the washings to 
the dish. The alcohol is then evaporated by placing the dish on the water- 
bath, after which it is dried for 2 hours in the air-oven at 100°, cooled 



Zeits. anal. Chem., 16, iSyy^j). 145. 



OILS AND FATS. 503 

i.i the desiccator, and weighed. After once heating for 2 hours, cooUng 
and weighing, heat again for half an hour, cool, and weigh. If a con- 
siderable loss in weight is found, heat for an additional half-hour. It is 
best, however, to avoid too prolonged heating, lest oxidation of the fatty 
acids should produce an increase in weight. 

INSOLUBLE FATTY ACIDS OF EDIBLE OILS AND FATS. 

Mustard oil gg 2-95 i 

Cottonseed oil g6 _g^ 

Corn oil g6 -g^ 

Lard g5 _g^ 

Peanut oil gj 8 

Sesame oil g^ _ 7 

Beef tallow g^ 6 

Mutton tallow g5 . 5 

Poppyseed oil 95 . 2-94. 9 

Rape oil 95 . i 

Sunflower oil 95 

Olive oil gj 

Cocoa butter g4.6 

Cocoanut oil go -88 . 6 

Butter 89 . 8-86 . s 

Saponification Number.— Koettstorfer's Method.— By the saponifica- 
tion number is meant the number of milligrams of potassium hydroxide 
necessary to completely saponify i gram of the fat. Between i and 2 
grams of the fat are transferred in the usual manner (see p. 489) to an 
Erlenmeyer flask, and 25 cc. of the alcoholic potash solution (40 grams of 
potassium hydroxide free from carbonates in i liter of 95% alcohol 
redistilled after standing for some time with potassium hydroxide) are 
added with a graduated pipette, which is allowed to drain for a noted 
period of time, say 30 seconds. The determination should preferably 
be made in duplicate. Conduct the saponification as in the case of the 
soluble fatty acids by heating on the water-bath. After saponification, 
remove from the bath, cool, and titrate with half-normal hydrochloric 
acid, using phenolphthalein as an indicator. Titrate also several blanks 
in which 25 cc. of the alcoholic potash solution are measured out with 
the same pipette as before, and allow to drain for the same amount of 
time. Subtract the number of cubic centimeters of half-normal acid 
necessary to neutralize the alkali in the case of the saponified fat from 
that necessary to neutralize the blank, multiply the result by 28.06, and 
divide the product by the number of grams of fat taken. 



504 



FOOD INSPECTION AND ANALYSIS. 



SAPONIFICATION NUMBER OF EDIBLE OILS AND FATS. 



Oil. 


Saponification No. 


Mustard oil 


170-178 
168-179 
188-193 
188-194 
189-194 
189-194 
191-19S 
185-196 
186-196 
190-196 
189-197 
190-198 


Rape oil 


Sesame oil 


Sunflower oil 


Maize oil 


Soy oil 


Cottonseed oil 


Olive oil 


Peanut oil 


Linseed oil 


Poppyseed oil 


Lard oil 





Fat. 


Saponification No. 


Mutton tallow 


192-195 

195 
192-197 
193-200 
192-202 
198-202 
193-203 
220-241 

242 
242-255 

251-257 
246-268 


Cottonseed stearin 


Oleo stearin 


Beef tallow 


Cacao butter 


Oleo oil 


Lard 


Butter 


Palm kernel stearin 


Palm kernel oil 


Cocoanut stearin 


Cocoanut oil 





The Iodine Absorption Number. — This determination is based on 
the well-known property of the unsaturated fatty acids to absorb a fixed 
amount of iodine under given conditions of time, strength of reagent^ etc. 

HiibVs Method.^ — The following reagents are necessary: 

(i) Iodine Solution, made by dissolving 26 grams of pure iodine in 
500 cc. of 95% alcohol, and, separately, 30 grams of mercuric chloride 
in 500 cc. of the same strength of alcohol. Filter the latter solution, 
if necessary, and mix the two together, allowing the mixture to stand 
at least 12 hours before using. As the solution loses strength rapidly, 
it should not be used in accurate work after it is 24 hours old. 

(2) Decinormal Thiosulphate Solution, made by dissolving 24.8 grams 
of the freshly powdered, chemically pure salt in water, and making 'up 
to I liter. 



Dingler's Polyt. Jour., 25, li 



p. 281. 



OILS AND FATS. 505 

(3) Starch paste, prepared by boiling i gram of starch in 200 cc. of 
water for ten minutes, then cooling. 

(4) Potassium Iodide Solution, made by dissolving 150 grams of the 
salt in water, and making up the volume to i liter. 

(5) Potassium Bichromate Solution for standardizing the thiosulphate, 
made by dissolving 3.874 grams of chemically pure potassium bichromate 
in distilled water, and making up the volume to i liter. 

The sodium thiosulphate solution is standardized as follows: 20 cc. 
of the potassium bichromate solution are introduced into a glass-stoppered 
flask together with 10 cc. of potassium iodide and 5 cc. of strong hydro- 
chloric acid. Then slowly add from a burette the sodium thiosulphate 
solution, till the yellow color of the solution has nearly disappeared, after 
which a little of the starch paste is added, and the titration carefully con- 
tinued to just the point of disappearance of the blue color. The reaction 
which takes place is as follows: 

K2Cr207+i4HCl+6KI = 2CrCl3+8KCl+6I+7H20. 

The equivalent of i gram of iodine in terms of the thiosulphate solu- 
tion is found by multiplying the number of cubic centimeters of the latter 
solution required for the above titration by 5. 

If, for example, 16.4 cc. of the thiosulphate solution are required 
for 20 cc. of the bichromate solution, then i gram of iodine is equivalent 
to 16.4X5 = 82.0 cc. of sodium thiosulphate solution, or i cc. of the thio- 
sulphate solution =^^^ = 0.0122 gram of iodine, i cc. of exactly deci- 
normal thiosulphate is theoretically equivalent to 0.0127 gram of iodine. 

The thiosulphate solution may also be standardized by means of 
iodine. A short tube closed at one end is tared, together with another 
tube of such a size as to fit over the first. Into the inner tube are 
introduced about 0.2 gram of resublimed iodine and the tube heated 
until the iodine melts, after which it is closed by the second tube and the 
whole cooled in a desiccator and weighed. The iodine is dissolved in 
10 cc. of 10% potassium iodide solution, the solution diluted with water, 
and the thiosulphate solution added with constant stirring until only a 
yellow color remains. Starch paste is then added, and the titration con- 
tinued until the blue color disappears. 

Manipulation. — Place 0.4 to i gram of the solid fat, or from 0.2 to 
0.4 gram of oil, in a glass-stoppered flask or bottle of 300 cc. capacity. 



506 FOOD INSPECTION AND ANALYSIS. 

In the case of oils, this may conveniently be done by difference, weigh- 
ing first a small quantity of the oil in a beaker with a short piece of glass 
tubing to serve as a pipette, transferring a number of drops of the oil 
from the beaker to the bottle, and again weighing the beaker and contents. 
The number of drops of oil required for the desired weight is first ascer- 
tained experimentally. 

The material may also be conveniently and accurately weighed in 
small, flat bottomed cylinders of glass about lo mm. in diameter and 15 
mm. high, which may be made by cutting off so-called " shell vials." 
Fats are introduced while melted, the weight being taken after cooling. 
The cylinder and fat are transferred together by means of forceps to 
the glass-stoppered bottle. 

Dissolve the oil in 10 cc. of chloroform, and after solution has taken 
place, add 30 cc. of the iodine solution, shake, and set in a dark place 
for three hours, shaking occasionally. The excess of iodine should be at 
least as much as is absorbed. When ready for the titration, add 20 cc. 
of the potassium iodide solution (the purpose of which is to keep in 
solution the mercuric iodide formed, which would otherwise precipitate 
on dilution) and 100 cc. of distilled water. Titrate the excess of iodine 
by the thiosulphate solution, which is slowly added from a burette till 
the yellow color has nearly disappeared, then add a little starch paste, 
and finally thiosulphate solution drop by drop until the blue color of 
the iodized starch is dispelled. Near the end of the reaction the flask 
should be stoppered and vigorously shaken, in order that all the iodine 
may be taken up, and sufficient thiosulphate should be added to prevent 
a reappearance of any blue color in five minutes. 

Two blanks are conducted at the same time and in similar flasks or 
bottles, in exactly the same manner as in the case of the above titration, 
except that the fat is omitted. This is to get the true value of the iodine 
solution in terms of the thiosulphate solution. 

Suppose, for example, in the case of the blanks, 30 cc. of the iodine 
solution required in one instance, 46.2 cc. of sodium thiosulphate solution 
and in the other 46.4 cc. The mean is 46.3. Suppose 30.7 cc. of thio- 
sulphate solution were required for the excess of iodine remaining over 
and above that absorbed by 0.5 gram of the fat in the above process. 
Then the thiosulphate equivalent to the iodine absorbed by the fat would 
be 46.3 — 30.7 = 15.6 cc, and the per cent of iodine absorbed would be 

11^.6X0.0122X100 „ ^ 
— = 38.06. 



OILS AND FATS. 



507 



IODINE NUMBER OF EDIBLE OILS AND FATS. 



Oil. 


Iodine No. 


Lard oil 


67- 88 

77- 95 

83-105 

94-105 

103-117 

104-117 

92-122 

I 16-130 

120-135 

121-143 

132-143 
170-202 


Olive oil 


Peanut oil 


Rape oil 


Sesame oil 


Cottonseed oil 


Mustard oil 


Maize oil 


Sunflower oil 


Soy oil 


Poppyseed oil 


Linseed oil 





Fat. 


Iodine No. 


Cocoanut stearin 


4- 6.6 
8 

8- 95 
13- 18 

8- 27 
26- 38 
32- 41 
35- 45 
32- 50 
40- so 
54- 70 
88-104 


Palm kernel stearin 


Cocoanut oil 


Palm kernel oil 


Oleo stearin 


Butter fat 


Cacao butter 


Beef tallow 


Mutton tallow 


Oleo oil 


Lard 


Cottonseed stearin 





The Hijbl method was long almost universally used for estimating 
the per cent of iodine absorbed, but is open to serious objections, chief 
of which are the tendency of the iodine solution to lose strength, and 
the length of time requu-ed to insure saturation of the oil with the iodine. 

The Wijs and Hanus modifications obviate these defects, the former 
being quite generally used in Europe and to a considerable extent in 
America, and the latter being the official method of the A, O. A. C. 

Tolman and Munson * have shown that with oils and fats having 
iodine numbers below 100, the three methods give practically identical 
figures, while with oils having high iodine numbers, the Wijs and Hanus 
modifications give higher results than the Hiibl method, but are doubt- 
less more nearly correct. Their results follow: 



'Jour. Am. Chem. Soc, 25, 1903, p. 244. 



508 



FOOD INSPECTION AND ANALYSIS. 



E 2 
2:< 



t-, M 






" r^ C 

3 E ^ 

C 3 O 

015, f^ 






o C c! 

C " m 



I 
2 

I 

4 

2 

36 

3 

S 

2 

I 
3 

I 
3 



Cocoanut oil 

Butter — minimum 

maximum, 

Oleo oil 

Oleomargarine — minimum 

maximum, 
Lard oil — minimum 

maximum, 
Olive oil — minimum 

maximum, 

average . . 
Peanut oil — minimum 

maximum 
Mustard oil — minimum 

maximum 
Rape oil — minimum 

maximum 

Sunflower oil 

Cottonseed oil — minimum 

maximum 

Sesame oil 

Corn oil — minimum 

maximum 
Poppyseed oil — minimum 

maximum 



34 

35 
42 

52 
66 
69 
73 
79 
89 
84 
94 
107 
98 

113 
100 

lOI 

106 
103 
106 
106 
119 
123 

134 



93 



9-05 
35-9 
36.2 

43-5 
52-9 
66.0 

70-5 
74-5 
79-9 
91.4 

8'5-3 

95-2 

109.5 

104-3 
118. 2 
104. 1 

105-7 
109.2 

105-3 
107-3 
107.0 
122.2 
129.2 
135-2 
139-1 



8.60 
35-4 
35-3 
43-3 
52.0 
64.8 
69.8 

73-9 

80.6 

90.0 

84.6 

94.1 

107.7 

103.8 

116. 8 

102.8 

105.2 

107.2 

105.2 

107.8 

106.5 

119. 6 

126.0 

132.9 

138.4 



+ 0.12 
+ 1.1 
-f 0.9 
4-0.9 
-f 0.4 

-0.3 
+ 1.2 

-f 0.7 
-f 0.7 
+ 1.6 

+ 1-3 
+ 0.7 
+ 1.8 
+ 5-9 
+ 5-2 
+ 3-9 
+ 4-4 
+ 2.8 

+ 1-5 
+ 1.1 
+ 0.6 
+ i-o 
+ 5-8 
+ 1.8 
+ 4-2 



-0.33 
-f 0.6 
-f 0.0 
+ 0.7 
-o-S 
-i-S 
+ 0.5 
-f 0.2 

+ 1-4 
+ 0.2 
-f 0.6 
— 0.1 
-f 0.0 
+ 5-4 
+ 3-8 
-f 2.6 
+ 3-8 
-f 0.8 

+ 1.4 
+ 1.6 
+ 0.1 
-f 0.4 
+ 2.7 
-o-S 
+ 3-5 



Hanus Modification.'^ — Reagents. — Iodine Solution. — Dissolve 13.2 gms. 
of pure iodine in i liter of pure glacial acetic acid (99%), and to the cold 
solution add 3 cc. of bromine, or sufficient to practically double the halo- 
gen content when titrated against the thiosulphate solution, but with 
the iodine slightly in excess. 

Decinormal Thiosulphate Solution, Starch Paste, and Potassium Iodide 
Solution, as in Hiibl's method. 

Method of Procedure. — Proceed as in Hiibl's method, substituting 
30 cc. of the Hanus iodine reagent for that of Hiibl, stirring the solu- 
tion before adding the water, and, instead of adding 20 cc. of the potas- 
sium iodide solution, use only 15 cc. The excess of iodine should be at 
least 60% of that added. 



* Zeits. Unters. Nahr. Genussm., 4, 1901, p. 913. 



OILS AND FATS. 509 

Only half an hour is required for full saturation of the oil by the 
iodine in the Hanus method, as against three hours in the Hiibl. In 
case of the non-drying oils and fats, the reaction takes place in from 
eight to fifteen minutes, though it is best to let the flask set for half an 
hour at least, in all cases. With oils having an iodine number in excess 
of ICO, Tolman and Munson recommend one hour's standing. 

On account of the high coefficient of expansion of acetic acid, care 
should be taken that the temperature is the same when the iodine solu- 
tion is measured for the blank and for the determination, as otherwise 
a serious error may be introduced. 

Wijs Modification.* — Reagents. — Iodine Solution. — Dissolve 13.2 grams 
of pure iodine in i liter of pure glacial acetic acid, and pass through the 
larger portion of this solution a current of carefully washed and dried 
chlorine gas f until the solution is practically decolorized. Finally add 
enough of the original solution of iodine in acetic acid to restore the 
iodine color, so that there is a slight excess of iodine. 

Hunfs Modified Iodine Solution. — Dissolve .10 grams of iodine tri- 
chloride in I liter of pure glacial acetic acid, and finally add and dissolve 
10.8 grams of pure iodine. 

Other Reagents, as in the Hiibl and Hanus methods. 

Method 0} Procedure. — Proceed as in the Hanus method, observing the 
same precautions, the only difference being in the use of the Wijs iodine 
reagent. 

Wijs recommends the following periods of time for absorption of 
the iodine: For non-drying oils and fats, such as peanut, olive, and 
cocoanut oils, butter fat, lard, and other animal fats, 15 minutes; 
for semi- drying oils, such as cottonseed, rape, sesame, corn, and 
mustard, 30 minutes; for drying oils, such as sunflower and poppyseed, 
I hour. 

The Bromine Index or Bromine Absorption Number. — The measure 
of the amount of bromine absorbed by the oils and fats is a useful factor. 
By the bromine index is understood the weight of bromine which is 
absorbed by i gram of a given oil. The bromine index of various oils 
has been determined as follows: 



* Ber. d. chem. Ges., 31, 1898, p. 750. 

t The chlorine is conveniently prepared by treatment of bleaching powder with dilute 
sulphuric acid, using gentle heat, and washing the gas by passing through strong sulphuric 
acid. 



510 



FOOD INSPECTION AND ANALYSIS. 





Bromine Index. 


Observer. 


Poppyseed 

Mustard 

Sesame 


0.835 
0.763 
0.69s 
0.645 
0.632 

0.530 
500 to 0.544 


Levallois 

Girard 

Levallois 

Girard 

Levallois 

1 1 


Cottonseed 


Rape 


Peanut 


Olive 



The following methods are at present seldom used : 

Method of Levallois* — Five grams of the oil are saponified with alco- 
holic potash in a 50-cc. graduated flask by the aid of a gentle heat. At the 
end of the saponification and after cooling, the flask is filled to the mark with 
alcohol, and, after shaking, 5 cc. are removed by means of a pipette and 
transferred to a flask. A slight excess of hydrochloric acid is added 
to set free the fatty acids, and from a burette a standardized solution 
of bromine water is run in till with constant shaking a permanent yellow 
color persists. The bromine is previously standardized with potassium 
iodide and sodium thiosulphate. The weight of bromine fixed by i gram 
of the fat is then calculated. 

MllPs Method. — Modified.-\ — Dissolve o.i gram of the filtered and 
dried fat in 50 cc. of carbon tetrachloride or chloroform in a loo-cc. stop- 
pered bottle. From a burette a standard solution of bromine in carbon 
tetrachloride, approximately tenth-normal (8 grams to a liter), is slowly 
added to the oil solution till, after fifteen minutes, a permanent coloration 
remains. The amount of bromine absorbed is calculated by comparing 
with the color similarly produced in a blank experiment, or an excess 
of bromine solution may be run in and the solution titrated back 
with a standard solution of thiosulphate, using potassium iodide and 
starch. 

Thermal Tests. — The rise in temperature produced by the action of 
certain reagents on various oils and fats, when applied in a definite 
manner, has been found to be of considerable value, especially in the case 
of sulphuric acid and of bromine. 



* Villiers et Collin, Les Substances Alimentaires, p. 680. 
tjour. Soc. Chem. Ind., 2, 1883, p. 435; 3, 1884, p. 366. 
Am. Chem. Soc, 16, 1894, p. 275; 21, 1899, p. 1084. 



See also Mcllhiney, Jour. 



^^m OILS AND FATS. 511 

^H The Maumene Test,* or thermal reaction with sulphuric acid, is most 
^Wadily carried out in a beaker of say 150 cc. capacity, which is set into a 
larger beaker or vessel of any kind, the space between the two being packed 
with felt or cotton waste. The inner beaker is removed, and into it is 
weighed 50 grams of the oil. It is then replaced and the packing adjusted, 
if necessaiy, after which the temperature of the oil is noted with a ther- 
mometer. From a burette containing the strongest sulphuric acid of 
the same temperature as the oil, 10 cc. are run into the beaker, at the 
same time stirring the mixture of acid and oil with the thermometer. 
The temperature rises ?oraewhat rapidly, and remains for an appreciable 
time at its maximum point, which should be noted. The difference 
in degrees centigrade between the initial temperature of the oil and the 
maximum temperature of the mixture expresses the Maumene number. 
With certain oils, as cottonseed, considsrabb frothing ensues when 
concentrated acid is employed, making an accurate determination of the 
Maumene number somewhat difficult. In this case it is better to employ 
a somewhat weaker acid, and to express results in terms of what is called 
the "specific temperature reaction." This is the result obtained by 
dividing the rise of temperature in the case of the oil by the rise of 
temperature in the case of water, using the same strength of acid, and 
multiplying the quotient by 100. Indeed, it is of importance in all 
cases to compare results on oils with those oblained by carrying out 
the same test on water. 

Bromination Test. — This test depends upon the avidity with which 
the oils and fats absorb bromine, the rise in temperature caused by the 
reaction being measured in this case rather than the actual amount of 
bromine absorbed, as in the case of the iodine absorption. Indeed, there 
is such a close relation between the iodine number and the heat of 
bromination, that when one is determined the other may be calculated 
quite closely by multiplying by a factor. In view of the fact that the 
heat of bromination is much more readily determined than the iodine 
number, it is often convenient to calculate the latter from the former, 
the result in the case of the edible oils and fats being quite sure to fall 
within the limits of variation of the iodine number of different oils of the 
same class. The bromination test was devised by Hehner and Mitchell,t 
who employed a vacuum jacketed tube for a calorimeter in which to 
make the test. Various modifications have been suggested both in the 

* Maumene, Compt. Rend., 35, 1852, p. 572. 
t Analyst, 20, 1895, p. 146. 



512 



FOOD INSPECTION AND ANALYSIS. 



apparatus employed and in the manner of diluting the oil and 
applying the reagent. The calorimeter employed by Gill and Hatch,* 
Fig. 96, is conveniently made and is very satisfactory. It consists of a 
long, narrow, fiat-bottomed tube, held by a cork in a small beaker, in 
such a manner that it is surrounded by an air jacket. The small beaker 
is set into one of larger size, the space between the two being packed with 
cotton waste. Five grams of the oil or fat are dissolved in 25 cc. 





A. B. 

Fig. 96. 
A. Gill and Hatch's Calorimeter for the Bromination Test with Oils. 
B. Wiley's Pipette for Measuring Bromine in Chloroform. 

of chloroform or carbon tetrachloride, and 5 cc. of this solution 
(containing i gram of the oil) are transferred by a pipette to the 
inner tube of the above calorimeter, being careful not to let it flow 
down the sides of the tube. The temperature of the oil is then taken 
by a thermometer graduated to 0.2°. The bromine reagent, which 
should be freshly prepared, is made up by measuring from a burette 
one part by volume of bromine into four parts of chloroform or carbon 
tetrachloride. The reagent is transferred to a measuring-flask devised 
by Wiley,t consisting of a side-necked filter-flask provided with a per- 



* Jour. Am. Chem. Soc, 21, 1899, p. 27. Gill, Oil Analysis, p. 50. 
t Jour. Am. Chem. Soc, 18, i8y6, p. 378. 



OILS AND I'ATS. 



513 



forated rubber stopper into which the stem of a 5-cc. pipette is fitted, 
Fig. 96. A bulb on the side-neck serves to fill the pipette. This pipette, 
filled to the mark with the bromine reagent (which should be at the same 
temperature as the oil solution in the calorimeter), is first covered bv the 
finger and removed, and its contents of 5 cc. allowed to flow down the 
sides of the inner tube of the calorimeter and mingle with the oil without 
stirring. The rise in temperature is very quick, and the highest point 
is noted. The difference between the highest and the initial temperature 
constitutes the heat-of-bromination number. 

This number, in the case of Gill and Hatch's calorimeter, is somewhat 
lower than when a vacuum jacketed tube is employed, and differs some- 
what with the diluent of the oil and bromine. In spite of these variations 
and that due to the personal equation, concordant results may be obtained 
with the vaiious oils, when the method is carried out under precisely the 
same conditions. The analyst should carefully work out the test several 
times with a particular oil till the results agree, and should then with 
equal care determine the iodine number of the same oil. The iodine 
number, divided by the heat-of-bromination number, gives the factor 
which is to be employed under the same conditions for calculating one 
constant from the other. In the case of Hehner and Mitchell's work 
with the vacuum tube, measuring i cc. of undiluted bromine into i gram 
of oil dissolved in 10 cc. of chloroform, it was found that the factor to 
be used in calculating the iodine number was 5.5. 

The following are some of the results on edible oils obtained by Hehner 
and Mitchell: 



Oil. 


Heat of 
Bromination. 


Iodine 
Number. 


Calculated 
Iodine Number. 


Lard .„ , 


10.6 
6.6 
15 

21-S 
19.4 


57-15 
37-07 
80.76 

122 

107.13 


58.3 

36.3 

82.5 

118 2 


Butter 


Olive oil. 


Corn oil 


Cottonseed oil 


106.7 





As in the case of the Maumene test with sulphuric acid (wherein 
the rise in temperature of sulphuric acid and water is taken as a standard), 
it is convenient to employ some standard for the bromination test, whereby 
varying results due to difference in apparatus, etc., may be compared. 

In this case Gill and Hatch found that sublimed camphor may be 
prepared sufficiently pure to be used for such a standard. Applying the 
bromination test with their calorimeter, as above described, to 5 cc. of a 



514 



FOOD INSPECTION AND ANALYSIS. 



solution of 7 J grams of camphor in 25 cc. of carbon tetrachloride, an average 
rise in temperature of 4.2° was obtained, and the specific temperature 
reaction is calculated for each oil by dividing the heat of bromination 
by this number. Furthermore, by dividing the iodine number of several 
oils by this specific temperature reaction, the factor to be employed for 
the calculation of the iodine number was found to be 17.18, as in the fol- 
lowing cases:* 



Oil. 



Specific Tem- 
perature 
Reaction. 



Iodine Number. 



Calculated. 



Found. 



Prime lard 
No. I lard. 

Olive 

Cottonseed 
Com 



-705 
.096 
.762 
.667 
-381 



63.8 

70-3 
81.8 

97-3 
109.5 



63.8 

73-9 

82.0 

103.0 

107.8 



The Acetyl Value. — On heating fats with acetic anhydride they 
become " acetylated " ; i.e., the hydrogen atom of their alcoholic hydroxy! 
group is exchanged for the acetic acid radicle, in accordance, for example, 
with the following reaction: 

C,,H32(OH)COOH+ (C3H30)30 = Ci,H33(0,C2H30)COOH+ C,H,0,. 

Ricinoleic Acetic anhy- Acetyl-ricinoleic Acetic 

acid dride acid acid 

By the actyl value is meant the number of milligrams of potassium 
hydroxide necessary to neutralize the acetic acid formed by the saponifi- 
cation of I gram of the acetylated fat. 

The Lewkowitsch method of procedure follows: t 10 grams of the 
oil are boiled with twice that weight of acetic anhydride for 2 hours in 
a flask with a return-flow condenser, and the mixture is then transferred 
to a large beaker containing 500 cc, of water, and boiled for 2 hours. 
To prevent bumping, a current of carbon dioxide is slowly passed through 
it during the boiling, introduced through a finely drawn, bent glass tube 
reaching nearly to the bottom of the beaker. The mixture on standing 
separates into two layers, of which the lower, or aqueous layer, is si- 



* Gill, Oil Analysis, p. 128. 

t Jour. See. Chem. Ind., 16, 1897, p. 503. 



OILS AND FATS. 515 

phoned off, and the oily layer boiled with fresh portions of water, which 
are in turn siphoned off, the operation being repeated till the wash water 
tests free from acid by litmus paper. 

The acetylated fat is then separated and dried by filtering through 
a dry paper at ioo° in an oven. If desired, the process may be carried 
out quantitatively, weighing the acetylated fat on a tared paper or in a 
tared dish as in the case of the insoluble acids, page 502. 

About 5 grams of the acetylated fat are weighed into a flask, and 
saponified with alcoholic potash in precisely the same manner as for 
the determination of the saponification number. Evaporate the alcohol 
and dissolve the soap in water. One of two methods may be carried 
out for freeing the acetic acid for titration, one by distillation and the 
other by filtration. In either case the water used must be boiled until 
free from carbon dioxide. 

For the former or distillation process, acidify the aqueous solution 
of the soap with i : 10 sulphuric acid, and distil in a current of steam 
until 600 to 700 cc. of distillate are obtained. The distillate should be 
received in a funnel with a loose cotton plug, so as to filter it free from 
insoluble acids mechanically carried over. The filtrate is titrated with 
tenth-normal sodium hydroxide, using phenolphthalein as an indicator. 
The number of cubic centimeters of alkali used is multiplied by 5.61, and 
the product divided by the number of grams of acetylated fat taken. The 
result is the acetyl value. 

If the filtration process is used (which is more rapid and should give 
concordant results with the distillation process), the exact amount of 
alcoholic potash used in the saponification should be accurately measured 
in carrying out the former part of the test, and the exact number of cubic 
centimeters of standard acid corresponding to the amount of alkali em- 
ployed should be added to the aqueous soap solution. The mixture 
should be gently warmed, and the fatty acids will gather in a layer at 
the top. These are filtered off and washed, till free from acid, with 
boiling water. The filtrate is titrated with tenth-normal sodium hy- 
droxide, and the acetyl value calculated as in the distillation process. 

ACETYL NUMBER OF EDIBLE OILS AND FATS. 

Lard 2.6 

Cacao Butter 2.8 

Linseed Oil 4.0 

Palm Kernel Oil t.q -8.4 



516 FOOD INSPECTION AND ANALYSIS.J 

Butter Fat T.9- 8.6 

BeefTallow 2.7- S.6 

Peanut Oil 9.1 

Olive Oil 10.6 

Cocoanut Oil » 0.9-12.3 

Rape Oil 14.7 

Cottonseed Oil 21 .0-25 .0 

Holland * has simplified the process and adopted as the rational 
acetyl number the milligrams of potassium hydroxide required for the 
saponification of the acetyl assimilated by i gram of the fat on acetylation 
(not I gram of the acetylated fat) thus making the number analogous 
to the other common fat constants. His process is as follows : 

Heat 5 grams of the sample with 10 cc. of acetic anhydride for 1-1.5 
hours in a 300-cc. Erlenmeyer flask under a reflux condenser on a boiling 
water-bath. Add sufficient ceresine to form a solid disk on cooling (0.4- 
0.5 gram for butter, less for hard fats, more for oils), heat on the water- 
bath with rotation until the mass is homogeneous, add carefully 150 cc. 
of boiling water and heat further with occasional agitation to remove 
occluded acetic acid. Cool in water, decant off the solution without 
disturbing the cake onto a dense ether-extracted filter. Repeat the 
treatment with water about 6 times or until the final filtrate gives a de- 
cided color with 2-3 drops of N/io alkali and phenolphthalein. 

Drain in a cool place, return to the flask small particles adhering to 
the filter, add 50 cc. of alcoholic potash (50 cc. saturated solution to 
1000 cc. of alcohol), 50 cc. of alcohol, a few glass beads, and boil under a 
reflux condenser on a water-bath for 60 minutes, or to complete saponifi- 
cation. Place in water at 60° C. and titrate with N/2 hydrochloric acid 
using as indicator phenolphthalein or preferably i cc. of a solution of 
alkali blue (6B) prepared by digesting i gram with 100 cc. of alcohol for 
several days at room temperature in a stoppered flask, with occasional 
shaking, and filtering. Boil and retitrate if necessary. Conduct blanks 
without ceresine. Calculate the saponification number of the fat after 
acetylation from these data. 

The acetyl number (in the new sense) is the difference between the 
saponification numbers of the fat before and after acetylation. 

The Valenta Test, f— This depends upon the solubility of the oil in 

* Jour. Ind. Eng. Chem., 6, 1914, p. 484. 
fDingler's polyt. Jour. 252, 1884, p. 296. 



OILS AND FATS. 517 

glacial acetic acid. Pour from 3 to 5 cc. of the oil into a test-tube, and 
add an equal volume of glacial acetic acid (specific gravity 1.0562). 
Place a thermometer in the tube and warm gently till the oil goes into 
solution. Then allow the mixture to cool, and observe the temperature 
at which the solution begins to appear turbid. 

Castor oil and oil of the olive kernel are soluble in glacial acetic acid 
at ordinary temperatures, rape, mustard seed, and other cruciferous oils 
are partly insoluble even in the boiling acid, while the other edible oils 
and fats become turbid at temperatures between 23° C. and the boiling- 
point of acetic acid. Tables have been prepared by Valenta, Allen, and 
others, showing the turbidity temperatures for different oils and fats, 
but as these figures are far from concordant, the analyst will do well to 
establish his own standards. 

Thompson and Ballantyne * found that the amount of free fatty 
acids and the specific gravity of the acetic acid exert a marked influence 
on the results. Fryer and Weston f dry the oil by hot filtration through 
cotton. 

The Elaidin Test was first suggested by Poutet in 18 19 and was for- 
merly much used. It is based on the conversion by nitrous oxide of liquid 
olein into the solid elaidin, a crystalline compound isomeric with olein, 
while other common glycerides remain liquid under treatment with this 
reagent. By the consistency of the final product, when subjected under 
certain conditions to the action of nitrous oxide, some idea as to the 
character of the oil may be gained. 

Manipulation. — To carry out the test according to Poutet (modified), 
weigh 5 grams of the oil into a beaker, add 7 grams of nitric acid (specific 
gravity 1.34) and about 0.5 gram of copper wire. Place the beaker in 
water at 15° and stir thoroughly with a glass rod in such a manner as 
to make an intimate mixture of the oil and the evolved nitrous oxide gas. 
After the wire has been dissolved, add another piece of about the same 
size and again stir vigorously. Set aside for about 2 hours, at the end 
of which, in the case of pure olive, almond, peanut, or lard oil, it will 
have been changed into a solid white mass. 

Nearly all the seed oils, especially cottonseed and mustard, are turned 
into a pasty or buttery mass. 

Another modification of Poutet's tests | consists in mixing 10 grams 

* Jour. Soc. Chem. Ind., 10, 1891, p. 233. 
t Analyst, 43, 1918, 3. 
Used in the Paris municipal laboratory. 



518 FOOD INSPECTION AND ANALYSIS. 

of the oil, 5 grams of nitric acid (specific gravity 1.38), and i grain of 

marcury in a test-tube, shaking for 3 minutes and allowing to stand 

20 minutes, when it is again shaken. 

The behavior of various oils after that time on further standing is as 

follows: 

Solidified after 

Olive oil 60 minutes 

Peanut oil 80 " 

Sesame oil 185 " 

Rape oil 186 " 

Archbutt * prepares the reagent previous to use by dissolving 18 grams 
of mercury in 15.6 c.c of nitric acid (sp. gr. 1.42) and uses 8 grams for 
96 grams of the oil, shaking every 10 minutes for 2 hours. 

Determination of Free Fatty Acids. — Weigh 5-20 grams of the oil or 
fat into a flask, add 50 cc. of neutralized 95% alcohol, warm in the case 
of fats until melted, shake thoroughly, and titrate with N/io alkali, using 
phenolphthalein as indicator. 

The result may be reported in terms of percentage of oleic acid (each 
cubic centimeter of tenth-normal alkali is equivalent to 0.0282 gram of 
oleic acid) or as the " acid number," by which is meant the number of 
cubic centimeters of tenth-normal alkali necessary to saturate the free 
acid in i gram of the fat or oil. 

Constants of the Free Fatty Acids. — Often much information as to 
the character of an oil or fat may be obtained by determining such con- 
stants of its fatty acids as the melting- and solidifying-point, the iodine 
number, etc. 

To prepare the fatty acids or if soluble acids are present the insoluble 
fatty acids, for examination, saponify a quantity of the oil or fat with al- 
coholic potash, evaporate the alcohol, and dissolve the soap in hot water. 
Decompose the soap by the addition of an excess of hydrochloric or sul- 
phuric acid, heat till the fatty acids rise in a layer to the top of the liquid, 
cool, remove the fatty acids, boil up again with water, and repeat until 
the mineral acid is removed. The melting-point, iodine number, etc., 
are determined as with the oil or fat itself. 

Solidifying-point of the Fatty Acids, or Titer Test. — Modified 
Wolfbauer Method. \ — Saponify 75 grams of fat in a metal dish with 60 cc. 



* Jour. Soc. Chem. Ind., 5, 1886, 304. 

t A. O. A. C. Method, U. S. Dept. of Agric, Bur. of Chem. Bui. 107, p. 135. 



OILS AND FATS. 519 

of 30% sodium hydroxide (36° Baume) and 75 cc. of 95^0 by volume 
alcohol or 120 cc. of water. Boil to dryness, with constant stirring to 
prevent scorching, over a very low flame, or over an iron or asbestos plate. 
Dissolve the dry soap in a liter of boiling water, and if alcohol has been 
used, boil for forty minutes in order to remove it, adding sufficient water 
to replace that lost in boiling. Add 100 cc. of 30% sulphuric acid (25° 
Baume) to free the fatty acids, and boil until they form a clear, trans- 
parent layer. Wash with boiling water until free from sulphuric acid, 
collect in a small beaker, and place on the steam bath until the water has 
settled and the fatty acids are clear; then decant them into a dry beaker, 
filter, using a hot-water funnel, and dry twenty minutes at 100° C. 

When dried, cool the fatty acids to 15 or 20° C. above the expected 
titer, and transfer to the titer tube, which is 25 mm. in diameter and 100 
mm. in length (i by 4 inches), and made of glass about i mm. in thickness. 
Place in a i6-ouncc saltmouth bottle of clear glass, about 70 mm. in 
diameter and 150 mm. high (2.8 by 6 inches), fitted with a cork, which is 
perforated so as to hold the tube rigidly when in position. Suspend the 
thermometer, graduated to 0.10° C, so that it can be used as a stirrer, 
and stir the mass slowly until the mercury remains stationary for thirty 
seconds. Then allow the thermometer to hang quietly, with the bulb in 
the center of the mass, and observe the rise of the mercury. The highest 
point to which it rises is recorded as the titer of the fatty acids. 
Test the fatty acids for complete saponification as follows: 
Place 3 cc. in a test tube and add 15 cc. of alcohol (95% by volume). 
Bring the mixture to a boil and add an equal volume of ammonium 
hydroxide (0.96 sp. gr.). A clear solution should result, turbidity indicat- 
ing unsaponified fat. The titer must be made at about 20° C. for all 
fats having a titer above 30° C. and at 10° C. below the titer for all other 
I fats. 

The thermometer must be graduated in tenth degrees from 10° to 60°, 

1 with a zero mark, and have an auxiliary reservoir at the upper end, also 

i one between the zero mark and the 10° mark. The cavity in the capillary 

tube between the zero mark and the 10° mark must be at least i cm. below 

I the 10° mark, the 10° mark to be about 3 or 4 cm. above the bulb, the 

i length of the thermometer being about 15 inches over all. The ther- 

' mometer is annealed for 75 hours at 450° C, and the bulb is of Jena 

' normal 16"' glass, moderately thin, so that the thermometer will be 

quick acting. The bulb is about 3 cm. long and 6 mm. in diameter. 

The stem of the thermometer is 6 mm. in diameter and made of the best 



520. FOOD INSPECTION AND ANALYSIS. 

thermometer tubing, with scale etched on the stem, the graduation to be 
clear cut and distinct, but quite fine.* 

Unsaponifiable Matter. — x\s will be seen by reference to the table 
on page 529, the unsaponifiable matter in pure edible oils and fats is 
comparatively insignificant in amount, consisting largely of cholesterol or 
phytosterol. A high content of unsaponifiable matter is indicative of 
adulteration, pointing to the presence of mineral or coal-tar oils, or to 
paraffin. 

Determination of Unsaponifiable Matter.f — Weigh 7 to 10 grams of 
the fat or oil in a 250-cc. flask, and saponify by boiling with 25 cc. of 
alcoholic potassium hydroxide and 25 cc. of alcohol under a return - 
flow condenser. After saponification, add 30 to 40 cc. of water, and 
bring to the boiling-point. Cool and transfer the contents from the 
flask to a separatory funnel, washing out the flask first with a small amount 
of 50% alcohol, and finally with 50 cc. of petroleum ether (B.P. 40^-70°), 
adding both washings to the separatory funnel. Shake the latter 
thoroughly, but avoid if possible forming an emulsion. If the latter 
persists in forming, add a volume of water equal to that of the soap solu- 
tion, which will sometimes break it up. After separation of the petro- 
leum ether layer, draw off the underlying soap solution into a beaker, 
and wash the petroleum ether two or three times with 50% alcohol, which 
is drawn off and added to the soap solution. The petroleum ether is 
then run into a tared Erlenmeyer flask, and the soap solution extracted 
twice more with fresh portions of petroleum ether, washing the ether 
each time with 50% alcohol as before and then transferring the ether 
to the tared flask. The petroleum ether is then removed by placing 
the flask on the water-bath, bumping being prevented by means of a 
spiral of platinum wire weighed with the flask. Finally remove all traces 
of 'remaining ether by blowing hot air through the flask, or, in the absence 
of mineral oils (some of which are volatile), dry in the water-oven to con- 
stant weight, cool in a desiccator, and weigh. 

Cholesterol and Phytosterol. — These are monatomic alcohols, and 
combine with the fatty acids forming esters. Both respond to the same 
reactions, and are separated by the same process from the oils and fats 
in which they occur. Phytosterol was long thought to be the same as 
cholesterol, and some confusion seems to have arisen from the fact that 
early writers purport to have found cholesterol in vegetable oils, when 

* Tolman, U. S. Dept. of Agric, Bur. of Chem., Bui. 90, p. 75. 
fHonig and Spitz, Jour. Soc. Chem. Ind., 1891, 1039. 



OILS AND FATS. 521 

in reality the substance was phytosterol. The latter first distinguished 
from cholesterol by Hesse, who named it. 

Cholesterol (C26H44O) crystalHzes in white, nacreous, monoclinic 
laminae, having a melting-point of 145° and specific gravity 1.067. Its 
reaction is neutral, it is devoid of taste or smell, insoluble in water, sparingly 
soluble in cold, but readily soluble in boiling alcohol, and soluble in ether, 
chloroform, methyl alcohol, benzene, and oil of turpentine. It sublimes 
unchanged at 200°, but at higher temperatures decomposes. 

Commercial cholesterol is obtained from wool oil and is known as 
lanolin, being used largely in medicine as a basis for ointment. 

Cholesterol occurs also in the yolk of eggs, in many animal secretions, 
and in most animal oils and fats. 

It separates in laminated, transparent crystals from a mixture of 
2 volumes alcohol and i volume ether, and in the form of anhydrous 
Deedles from chloroform. 

Phytosterol (C26H440,H20) is most abundantly found in the legu- 
minous seeds, and is prepared commercially from these, especially from 
peas and lentils. It is a constituent of most vegetable oils. 

It crystallizes in slender, glittering plates from chloroform, ether, 
and petroleum ether, and from alcohol in tufts of needles. In solubility it 
much resembles cholesterol, but its melting-point from 132° to 134° is lower. 

Determination of Cholesterol and Phytosterol. — Method of For ster and 
Reichmann* — 50 grams of the oil or fat are boiled for five minutes in 
a flask connected with a reflux condenser with two successive portions 
of 75 cc. of 95% alcohol, and in each case the alcoholic solution is sepa- 
rated by means of a separatory funnel. The combined alcoholic solutions 
are then boiled in a flask provided with a funnel in the neck, till one- 
fourth of the alcohol is evaporated, and then poured into an evaporating 
dish and brought to dryness. The residue is then extracted with ether, 
and the ether solution is evaporated to dryness, taken up again with ether, 
filtered, evaporated once more, and dissolved in hot 95% alcohol, from 
which it is allowed to crystallize. Cholesterol or phytosterol will crys- 
tallize out under these conditions, and may be weighed. 

Distinguishing between Cholesterol and Phytosterol. — It is some- 
times of importance to determine which of these substances is present in 
an oil, or whether indeed both occur. Confirmatory proof as to the 
presence of vegetable in animal oils may, for instance, be established by 

* Analyst, 22, 1897, p. 131. 



522 FOOD INSPECTION AND ANALYSIS. 

showing whether the unsaponifiable residue in the sample contains choles- 
terol or phytosterol or both. Hehner * has made use of this test in deter- 
mining the presence of cottonseed oil in lard. 

The most ready means of distinguishing between cholesterol and 
phytosterol is furnished by the marked difference between the form of the 
' crystals, the manner of crystallization of the two substances, and the 
melting points of the acetates. 

Separation and Crystallization of Cholesterol and Phytosterol. — 
Bamer^s Method.^ — Saponify loo grams of the fat by heating in a liter 
Erlenmeyer flask on a boihng w^ater bath with 200 cc. of alcohohc potash 
S'Dlution (200 grams of potassium hydroxide -fi liter of alcohol). The 
flask should be provided with a perforated rubber stopper, through which 
passes a glass tube 700 cm. long, which serves as a reflux condenser. 
During the flrst part of the heating shake often and vigorously until the 
solution is clear, after which continue the heating one-half to one hour 
longer with occasional shaking. 

While still warm, transfer to a separatory funnel of about 1.5 liters 
capacity, rinsing the flask with 400 cc. of water. When cool, add 500 cc. 
of ether, shake vigorously for one-half to one minute, opening the cock 
repeatedly, and allow to stand for two to three minutes until the liquids 
separate. Remove the ether solution to a flask, and distil off the ether, 
using a few pieces of pumice stone to prevent bumping. Shake the soap 
solution two to three more times in the same manner with 200 to 250 cc. 
of ether, add the ether solution after each shaking to the residue in the 
distiUing flask, and distil off the ether. 

Usually a small amount of alcohol remains in the flask after removal 
of the ether, which may be removed by heating on a boiling water bath 
in a blast of air. To saponify any remaining fat, add 20 cc.of the alcoholic 
potash solution, and heat for five to ten minutes as before. Transfer 
to a small separatory funnel, rinse with 40 cc. of water, cool and shake 
with 150-200 cc. of ether from one-half to one minute, allow to stand two 
to three minutes, and draw off the lower layer. Wash the ether solution 
three times with 10-20 cc. of water, filter, to remove drops of water, into 
a smafl beaker, and remove the ether by cautious evaporation on the 
water bath, thus obtaining the crude cholesterol or phytosterol. 

The unsaponifiable residue, which may be weighed after drying, in 
the case of animal fats shows beautiful radiating crystals, and consists 

* Ibid., 13, 1888, p. 165. 

t Zeits. Unters. Nahr. Genussm., i, 1898, p. 31. 



I 



OILS AND FATS. 523 

largely of cholesterol, while in the case of vegetable fats it consists largely 
of phytosterol. Dissolve the residue in 4-20 cc. of absolute alcohol with 
the aid of heat, and allow to crystallize slowly in a shallow dish. 

The crystallization in the case of cholesterol alone begins from the 
margin of the lif|uid and gradually extends inward toward the center, 
forming a uniformly bright, thin, colorless film over the whole surface. 
This film is best removed with a knife or spatula and pressed between 
filter-paper. The film will be seen, even megascopically, to be composed 
of large, glossy plates with a silk-like luster. After the removal of the 
first film a second will form similar to the first, but composed as a rule 
of smaller crystals. These are removed in hkc manner, dried between 
filters, and added to the first in a glass. After the second crop, the mother 
liquid is thrown away. The crystals are then redissolved in absolute 
alcohol, and again allowed to separate out, being repeatedly recrystallized 
till the melting-point is constant. In lard and most fats the crystals 
were found pure by Bomer after the second crystallization. 

Phytosterol is crystallized with greater difficulty, especially when 
derived from seed oils, on account of the presence of pigments and other 
foreign matter. The first procedure is the same as above described for 
cholesterol, the crystals being allowed to separate slowly out of a solu- 
tion in absolute alcohol. Unlike cholesterol, no film is formed on the 
surface, but needles (sometimes i cm. in length) are gradually elim- 
inated, beginning at the margin and extending inward moslly at the 
bottom. In concentrated solutions, fine needles would be uniformly 
deposited through the liquid. These are best separated from the mother 
liquid by filtration, as they are not easily taken out with a knife. They 
may be washed on the filter with small amounts of absolute alcohol for 
microscopical examination, or repeatedly recrystallized, as in the case 
of cholesterol, till the melting-point is constant. 

1. Cholesterol Crystals. — ^When crystahized separately under above 
conditions, cholesterol crystals viewed under the microscope show generally 
rhomboidal forms of plates, as in Fig. 97, but sometimes with a reenter- 
ing angle. The plates are often grown together in masses. The most 
characteristic forms are found from the first crystallization or from 
the first film removed. Sometimes quadrilateral crystals predominate 
among the plates, often also the other shapes shown are found most 
numerous. 

2. Phytosterol Crystals. — Pure phytosterol crystallizes in needles or 
narrow plates, arranged commonly in star form or in bunches. The 



524 



FOOD INSPECTION AND ANALYSIS, 



most common forms are shown in Fig. 98, best conditions as to shape 
of crystals being obtained from slow crystallization, in which case the 
needles are finer and more regular. 

The crystals are commonly in the form of long, narrow plates, thin 
and slender, often pointed at both ends. Sometimes the points are 
lacking, or the ends are beveled. The more frequently they are re- 
crystallized, the larger and more varied are the crj'stal forms. The 




Fig. 97. — Cholesterol Cr>'stals under the Microscope. (After Bomer.) 

broad, hexagonal and quadrilateral plates shown are products of re- 
crystallization; the shorter forms are rarely met with. Sometimes various 
forms are found side by side in the same cr}'stallizat:on. 

Ph}'tosterol crv'stals, from a second of third recrj'stallization, some- 
times grow together in bunches resembling at fitst glance to the naked 
eye the cholesterol masses. They never do this in the first crj'^staUization, 
whereas in the case of cholesterol the growing together in masses is very 
characteristic of the first crj'stallization. 




V^ 



Fig. 98. — Phj-tosterol Crj-stals. (.\fter Bomer.) 

Thus for purposes of distinguishing between the two the product 
of the first cr}'Stallization is best observed. 

3. Crystals of Mixed Cholesterol and Phytosterol. — In mixtures of the 
two they do not crv^stallize separately, but when in nearly equal propor- 
tion, or with ph}i;osterol predominating, the crj^stals much resemble 
phjliosterol. Even when cholesterol predominates to the extent of 20 
parts to I of phytosterol, the mode cS cr)'stallization leans most toward 



OILS AND FATS. 



525 



that of phytosterol, though the needles are of different shape. Such a 
mixture, for instance, does not form in a film like cholesterol, but, like 
ph}tosterol, comes out in needle-like bunches. The needles, however, 
are more often like those shown in Fig. 99 when viewed under the micro- 




n 




Fig. 99. — Characteristic Forms of Crystallization of Mixed Cholesterol and Ph}i;osterol 

(After Bomer.) 

scope, sho"\^'ing needles for the most part squarely cut off at the ends, 
and sometimes placed end to end, and of var}'ing diameter, giving the 
appearance of a spy-glass. WTien cholesterol predominates over phy- 
tosterol 50 to I, the plates resemble those of cholesterol. 

Bomer's Phytosterol Acetate Test for Vegetable Fats.* — Dissolve 
the crude cholesterol or phytosterol, or the mixture of the two, obtained 
by Bomer's method, as described on page 522, in the smallest possible 
amount of absolute alcohol, and allow to crystallize. Examine under 
the microscope the first crystals that separate, comparing with the cuts 
and descriptions given in the preceding section. Remove the alcohol 
completely by evaporation on the water bath, add 2 to 3 cc. of acetic 
anhydride, cover with a watch glass, and boil for one-fourth minute on a 
wire gauze; then remove the watch glass, and evaporate the excess of 
acetic anhydride on the water bath. Heat the residue with sufficient 
absolute alcohol to dissolve the esters, and add enough more to prevent 
immediate crystallization on cooling. Cover until the room temperature 
is reached and allow to crystallize. 

After one-half to one-third of the liquid has evaporated and the greater 
part of the esters have crystallized, transfer the crystals to a small filter 
by the aid of a small spatula, rinsing with two portions of 2 to 3 cc. of 
95% alcohol. Return the crystals to the crystallizing dish, dissolve in 
5 to ID cc. of absolute alcohol, and again allow to crystallize. After the 
greater part of the crystals have separated, collect on a filter as before. 
Repeat the recrystallization several times (5 to 6 is usually sufficient), 
determining the melting point of the crystals after each recrystallization 
beginning with the third. 



Zeits. Unters. Nahr. Genussm., 4, 1901, p. 1070. 



526 FOOD INSPECTION AND ANALYSIS. 

If after the last crystallization the corrected melting-point of the 
crystals is above ii6°, the presence of a vegetable fat or oil is indicated, if 
it is II 7° or higher the proof may be regarded positive. 

The standard thermometer used should be graduated to tenths of a 
degree. Correct the reading by the following formula: 

S=T+o.oooi^4n(T —t) 

in which 6*= the corrected melting-point, T=ihe observed melting-point, 
w = the length of the mercury column above the surface of the liquid, 
expressed in degrees, and / = the temperature of the air about the mercury 
column as determined by a second thermometer. 

Bomer states that by this method the analyst can detect in edible 
animal fats i to 2 per cent of oils rich in phytosterol (cottonseed, peanut, 
sesame, rape, hemp, poppy, and linseed), and 3 to 5 per cent of oils con- 
taining smaller amounts of this constituent (olive, palm, palm kernel, 
and probably cocoanut). He found the corrected melting-point of choles- 
terol acetate to be 114.3° to 114.8° and of phytosterol acetate, 125.6° to 
137.0°, according to the source. 

Klosterman Digitonin Method * Modified by Kiihn, Benger, and Wer- 
werinke.'f — To the fatty acids, separated from 50 grams of the sample in 
the usual manner, contained in a beaker, add 25 cc. of a 1% solution of 
digitonin (crystalline) in 95% alcohol, and heat at 70° C. for 30-45 minutes 
with occasional stirring until the precipitate of digitonides separates. 
Add 15-20 cc. of chloroform, filter, using suction, wash successively with 
chloroform and with ether until all the fat is removed, and dry. Boil 
the dried precipitate with 3-5 cc. of acetic anhydride for 5 minutes, add 
while hot 4 volumes of 50% alcohol, and allow the crystals of sterol acetate 
to separate. Filter, recrystallize from ether, and determine the melting- 
point as above described. 

Numerous experiments, made both in Europe and America, show that 
feeding milch cows and swine with oil cakes does not introduce phyto- 
sterol into either the fat of the milk or the lard, although both fats may 
respond to the Halphen test, or give abnormally high Polenske numbers 
as a result of feeding with cottonseed or cocoanut cake respectively, and 
although the lard (not the butter fat) may respond to the Baudouin test, 
owing to feeding with sesame cake. (See pages 552 and 579). 

* Zeits. Unters. Nahr. Genussm., 26, 1913, p. 433. 
t Ibid., 28, 1914, p. 369; 29, 191S, p. 321. 



OILS AND FATS. 527 

ParaflSn, sometimes used as an adulterant of fats, is included in the 
unsaponifiable matter determined as described on page 520. If present 
in an amount sufficient to indicate substitution for a more valuable fat 
the hot solution of the soap will be cloudy, showing often oily drops, and the 
percentage of unsaponifiable matter will be far in excess of normal. The 
characteristics of the unsaponifiable matter useful in further identification 
are the iodine and saponification numbers (nearly zero), the refraction, 
and the melting-point, although the latter will be modified in a degree 
by the presence of the small amount of sterols. 

For the detection of minute amounts, said to be used to misguide the 
analyst in interpreting the results of the phytosterol acetate test, Polenske's 
method * may be applied. 

Microscopical Examination of Oils and Fats. — In the examination of 
lard and butter for adulterants, the use of the microscope is often of great 
value, and will be described more fully under these special fats. In general, 
the best fat crystals are obtained by slow crystallization at room tempera- 
ture from an ether solution, or. from a mixture of ether and alcohol. The 
first crystals formed may often with advantage be filtered out, and washed 
with the alcohol and ether mixture on the filter, dissolved finally in ether, 
and the latter allowed to evaporate spontaneously. The crystals are 
then examined in a medium of ether. 

If it is desired to separate the liquid oleins from an oil, so that crystals 
of the solid fats are left for examination. Gladding f recommends dis- 
solving the fat in a mixture of two volumes of absolute alcohol and one 
volume of ether in a test-tube, which is stoppered with cotton and set 
for half an hour in ice water, during which time the more solid stearin 
and palmitin will have crystallized out. This portion is then separated 
from the mother liquor by filtration through an alcohol-wet filter-paper, 
and the crystals finally treated as in the preceding section, being examined 
in a medium of olive or cottonseed oil. 



CONSTANTS AND VARIABLES OF COMMON EDIBLE OILS AND FATS. 

The tables on pages 528 and 529, based on the results of numerous 
analysts, are designed merely as a guide. The figures given are not the 



* Arb. kaisl. Gsndhtsamt., 22, 1905, p. 576. 
t Jour. Amer. Chem. Soc, 18, 1896, p. 189. 



I 



528 



FOOD INSPECTION AND ANALYSIS. 



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1 



530 FOOD INSPECTION AND ANALYSIS. 

extreme limits reported in the literature, but rather the limits between 
which the results of analyses of commercial samples will ordinarily fall. 
Since the figures for each fat are not based on the same set of analyses made 
by the same analyst, some inconsistencies may be expected. 

OLIVE OIL. 

Source. — Olive oil is derived from the fruit of the cultivated thorn- 
less olive tree, Oka Europcea saliva, of which there are a great many 
varieties, originally grown in Asia Minor, Greece, Palestine, southern 
Europe, and northern Africa, and now cultivated also in California, Peru, 
and Mexico, as well as in Australia. Most of the olive oil of commerce 
is supplied by Italy, Spain, southern France, Tunis and Algeria. The tree 
is an evergreen of slow growth and great longevity. 

The ripe olive fruit is purple or purplish black in color; it is round or 
oval in shape, and from 2.5 to 4 cm. in diameter. The oil is contained in 
the parenchyma cells of the fruit suspended in a watery fluid. A thick 
skin incloses the fruit, and within is a kernel, which itself contains oil. 
The fruit flesh of European olives may, according to Lewkowitsch, contain 
as high as 70% of oil, but on an average contains about 50%. California 
olives, as shown by analyses made by Colby at the California experiment 
station, have a lower oil content, over 32% in the flesh or 24% in the 
whole fruit being exceptional. 

Preparation. — The finest virgin oil is produced from hand-picked, 
peeled olives, from which the kernels or pits have been removed. A 
somewhat inferior grade of oil is produced from the whole olive including 
the pit, while a distinctly low grade oil is obtained from the stones, or 
kernels, which are ground into a coarse meal and subjected to pressure, or 
to the action of such solvents as carbon bisulphide. 

In the process of manufacture the fruit, picked when nearly ripe, is 
reduced to a pulp in a stone or iron mill, and the pulpy mass, contained 
in baskets or bags, is subjected to pressure in an iron press. The very 
highest grade of virgin oil is that which runs out from the pulp with little 
or no pressure. After the first pressing, the pomace is ground, treated with 
water, and again subjected to pressure. Several pressings in this manner 
may be carried out, each yielding an oil inferior to that preceding, the 
lowest grades being used for lubricants and in the manufacture of 
soap. 

The oil as it runs from the press being turbid is clarified by washing and 



OILS AND FATS. 531 

filtering. It is stated that Italian olive oil is sometimes bleached by shak- 
ing with a solution of tannic acid.* 

Nature and Composition.— The better grades of olive oil, suitable for 
table and medicinal purposes, possess a pleasant, bland taste, and a dis- 
tinctive and agreeable odor, unmistakable in character for that of any 
other oil. The finest virgin oil is pale green in color, due to the presence 
of chlorophyll, which is closely associated with the oil globules in the 
cellular tissue of the fruit. Some varieties of olive oil are nearly color- 
less, while others are a deep golden yellow. 

Olive oil is very soluble in chloroform, benzol, and carbon bisulphide, 
but sparingly in alcohol. Three parts dissolve in 5 of ether. 

For range of constants see pages 528 and 529. 

For customs purposes the United States Government considers a 
gallon equivalent to 7.56 pounds, which is slightly below the truth. 

Solid fatty acids constitute from 2 to 18% of the total fatty acids (Tol- 
man and Munson). Tkey consist of palmitic with a small amount of 
arachidic acid. Stearic acid is absent. The liquid acids are oleic (over 
90%) and linolic acids. Gill and Tufts f have shown that olive oil con- 
tains phytosterol, not cholesterol, and is not therefore, as once held, an 
exception among vegetable oils. 

Substitutes. — As a rule the low-grade olive oils are most subject 
to adulteration, by reason of the fact that it hardly pays to destroy or even 
modify the fine quality and delicacy possessed by a first-class oil, which 
would inevitably be the result if even a small amount of foreign oil were 
added. Furthermore, if olive oil be sightly rancid or high in free fatty 
acids, the admixture of a bland oil tends to conceal the fact. 

The most common substitute and adulterant of olive oil in this country 
is naturally cottonseed oil, while in Europe peanut, sesame, poppyseed, rape 
sunflower and other oils are used. Leach has found in samples of alleged 
olive oil sold in Massachusetts cocoanut oil J and even fish oil. 

Pure Olive Oil of the U. S. Pharmacopoeia. — The requirements of 
the Pharmacopoeia are as follows : 

Specific gravity, 0.910 to 0.915 at 25° C.; iodine value not less than 

* Anal, fals., 4, 191 1, p. 355. 
t Jour. Am. Chem. Soc, 25, 1903, p. 498. 

t A sample of alleged olive oil purchased in a Massachusetts drug store and found to 
be adulterated with cocoanut oil, had the following constants: 

Specific gravity 0.911 Iodine number 74.5 

Reichert-Meissl number 2 . 90 Butyro-refractometer at 26° 56 . 5 



532 



FOOD INSPECTION AND ANALYSIS. 



79 nor more than 90; saponification value 190 to 195; very slightly soluble 
in alcohol, but readily soluble in ether, chloroform, or carbon disulphide. 

When cooled to from 10° to 8° C, the oil becomes somewhat cloudy 
from the separation of crystalline particles, and at 0° C. it usually forms a 
whitish, granular mass. 

Olive oil should not show the cottonseed oil reaction with the Bechi and 
Halphen test, pages 536 and 537, nor the sesame oil reaction with the 
Baudouin test, page 538. 

U. S. Standards. — Olive oil is the oil obtained from the sound, mature 
fruit of the culti\'ated olive tree {Olea europoea L.) and subjected to the 
usual refining processes; is free from rancidity; has a refractive index 
(25° C.) not less than 1.4660 and not exceeding 1.4680; and an iodine 
number not less than 79 and not exceeding 90. Virgin olive oil is olive 
oil obtained from the first pressing of carefully selected, hand-picked olives. 

Neither the pharmacopoeial nor the federal standards places a limit 
for free fatty acids. Archbutt considers that they should not exceed 4% 
(calculated as oleic) in oil designed for food. Analyses made by Colby 
indicate that genuine olive oil produced in California has a higher iodine 
number than the European product, reaching 90 and even higher. Sam- 
ples from other regions have been reported to have an iodine number 
over 90. 

Hauchecome or Nitric Acid Test. — Pure olive oil, when shaken or 
stirred with an equal volume of concentrated nitric acid, turns from a pale 
to a dark-green color in a few minutes. If, under this treatment, a reddish 
to an orange, or brown coloration is produced, the presence of a foreign 
vegetable oil (usually a seed oil) is to be suspected. The test should be 
used with caution and under no circumstances regarded as final. 

Bach gives the following table showing the action of strong nitric acid 
on various oils: 



Kind of Oil. 



After Agitation 
with Nitric Acid. 



After Heating for 
Five Minutes. 



Consistency after 

Standing Twelve to 

Eighteen Hours. 



Olive 

Peanut 

Rape 

Sesame 

Sunflower. . 
Cottonseed 
Castor . . . . , 



Pale green 
Pale rose 
. Pale rose 
White 
Dirty white 
Yellowish brown 
Pale rose 



Orange-yellow 
Brownish yellow 
Orange-yellow 
Brownish yellow 
Reddish yellow 
Reddish brown 
Golden yellow 



Solid 

Solid 

Solid 

Liquid 

Buttery 

Buttery 

Buttery 



OILS AND FATS. 



533 



The Zeiss Butyro-refractometer furnishes one of the most useful 
and easily applied preliminary means of judging the purity of the sample. 
If the reading is beyond the limits of pure olive oil, it at once indicates 
adulteration and often points to the particular adulterant. On the other 
hand, it is not always safe to assume the oil to be pure if the reading is 
correct, since mixtures of higher and lower refracting foreign oils may 
be so skillfully prepared as to read well within the limits of the pure oil 
on the refractometer scale. The refractometer reading of pure cottonseed 
oil is almost five degrees higher than that of pure olive. 



READINGS ON ZEISS REFRACTOMETER OF OLIVE AND COTTONSEED 

OILS.* 


Temperature 


Scale Reading. 


Temperature 
(Centigrade). 


Scale Reading. 


(Centigrade). 


Olive Oil. 


Cottonseed Oil. 


OUve Oil. 


Cottonseed OiL 


3S-0 
34-5 
34-0 
33-5 
33-0 
32.5 
32-0 

31-5 
31.0 

30-5 
30-0 

29-5 
29.0 

28.5 
28.0 

27-5 
27.0 
26.5 
26.0 


57-0 
57-2 
57-4 
57-7 
58-0 

58-3 
58.5 
59-0 
59-2 
59-4 
59-9 
60.1 
60.3 
60.6 
60.9 
61. 1 

61-5 
62.0 
62.2 


61.8 
62.1 
62.3 
62.5 
62.8 
63.0 
63.2 
63.6 
64.0 
64.2 

64-5 
64.9 
65.1 
65-3 
65-7 
66.0 
66.5 
67.0 
67-3 


25-S 
25-0 
24-5 ■ 
24.0 

23-5 
23.0 
22.5 
22.0 

21-S 
21.0 

20.5 
20.0 

19-S 
19.0 

18.5 
18.0 

17-5 
17.0 

16.5 


62.4 
63.0 

63-3 
63.6 

63-9 
64.2 

64-5 
64.8 
65.1 
65-4 
65-7 
66-0 
66.3 
66.6 
66.9 
67.2 

67-5 
67.8 
68.1 


67-5 
67.9 
68.2 
68.5 
68.8 
69.1 
69.4 
69.7 
70.0 

70-3 
70.6 
70.9 
71.2 

71-5 
71.8 
72.1 
72-4 
72-7 
73-0 



The Elaidin Test, in the case of pure olive oil, is very distinctive, since 
it yields by far the hardest elaidin of all the common oils, and solidifies 
the most quickly. 

Archbutt f shows the effect on this test of the mixture with olive oil 
of various proportions of rape and cottonseed oil, as follows: 



Kind of Oil. 


Minutes Required for Solid- 
ification at 25° C. 


Consistency. 


Olive oil 


230 

320 

From 9 to ii^ hours 

'• 9 "Hi " 
More than 11 J " 


Hard but penetrable 
Buttery 


" +10% rape oil 


'« -f20% " 


" + 10% cottonseed oil 

" +20% " 


Very soft. 
<< It 



* Ann. Rep. Mass. State Bd. of Health, 1899, p. 647. f Jour. Soc. Chem. Ind., 1897, p. 447'. 



534 FOOD INSPECTION AND ANALYSIS. 

Cottonseed Oil as an adulterant is best detected by means of the Hal- 
phen or Bechi tests. Its presence in notable quantities increases the 
specific gravity, refractometer reading, and iodine number very materially. 
Its high Maumene figure is also distinctive. 

Peanut Oil, when present to a considerable extent, betrays its presence 
by its peculiar bean-like flavor. Most of the constants of peanut oil 
lie within the limits of olive oil, with the exception of the higher iodine 
number and refractometer reading. A considerable admixture of peanut 
oil raises the refractometer reading perceptibly over that of pure olive. 
Its presence is best shown positively by tests for arachidic acid (p. 543), 
noting that traces of arachin have been reported in pure olive oil, insuf- 
ficient, however, to interfere with the detection of added peanut oil. 

Sesame Oil differs more particularly from olive in its higher specific 
gravity and iodine and Maumene numbers, and is readily detected by 
distinctive color tests. 

Rape and Mustard Oils are characterized by much lower saponification 
values and higher iodine numbers than olive. They contain erucic acid. 

Com Oil differs materially from olive in its exceedingly high iodine 
number and refractometer reading. Its specific gravity and saponifica- 
tion numbers are also higher. 

Lard Oil, when present in considerable quantity, is often rendered 
apparent by its characteristic odor on warming. Its low refractometer 
reading and iodine number are also distinctive. 

Poppyseed Oil differs most widely from olive oil in its refractometric 
reading, its high dispersion, and its Maumene number, which in the case 
of poppyseed is 87° and of olive about 42°. 

Cocoanut Oil perceptably raises the solidifying-point. If over 12% 
is present, the sample will become solid when placed in ice water. The 
low iodine number is distinctive. 

Fish Oils, when present, are rendered apparent by reason of their 
strong taste and smell, and by their very high iodine number. Boiling 
with sodium hydroxide develops a peculiar reddish coloration. The 
insoluble bromide test is most decisive. 

Routine Examination of Olive Oil for Adulterants. — First note the 
smell and taste of the sample, and then take the refractometer reading. 
An abnormally high refraction indicates adulteration. Next test for cotton- 
seed oil by the Halphen reaction, for sesame oil by the Baudouin reaction 
or its equivalent, and also apply the Hauchecorne test. Then test for 
arachidic acid (peanut oil) and for erucic acid (cruciferous oils). Finally 



OILS AND FATS. 535 

determine the iodine number and other constants if the qualitative tests 
indicate an admixture; an iodine number as high as 90 is strong indication 
of adulteration except in the case of California or North African oils. 

The edible oils and adulterants are arranged in order of their relative 
price about as follows: Olive oil, peanut oil, lard oil, sesame oil, poppy- 
seed oil, rape oil, corn oil, cottonseed oil. 

COTTONSEED OIL. 

Source and Preparation. — This oil, largely used as a table oil and as 
substitute for olive oil, is derived from seeds of the various species of the 
cotton plant, Gossipium, of which the most common are G. herbaceum, 
native to Asia, but cultivated extensively in southern Europe and in the 
United States, G. arbor eum, in Asia and Africa, and G. barbadense, in the 
West Indies. G. religiosum and hirsutum are varieties of G. herbaceum. 

Cottonseeds contain 5 to 30% of oil according to the variety and are 
a by-product in cotton production. They are dark brown or black, irreg- 
ularly oval, measuring from 5 to 8 mm. greatest diameter. Bombay and 
American upland cottonseed, after ginning, is still woolly, that is, bears 
a considerable coat of fiber, while Egyptian and Sea Island seed are 
naked. In the United States the seed is commonly decorticated before 
pressing although the ground hulls are now commonly added to the ground 
cake or meal. 

The seeds, whether or not decorticated, are cut into small pieces, 
crushed between rollers, and afterward submitted to hydraulic pressure 
in bags to express the oil, which is clarified by filtration or refined. The 
refining consists in washing the crude oil with sodium hydroxide solution, 
whereby the impurities are dissolved and thus removed. 

Nature and Composition. — Refined cottonseed oil is a pale yellow oil 
of thick consistency, possessing a bland though pleasant taste and odor. 

On cooling the oil to a temperature below 12° C. particles of solid 
fat will separate. At about 0° to —5° C. the oil solidifies. With con- 
centrated sulphuric acid, a dark, red-brown color instantly appears. 

For range of constants see pages 528 and 529. 

The solid fatty acids constitute from less than 20 to over 30% of the 
total acids, the lower figure being for winter oils. They consist largely 
of palmitic acid with a small amount of arachidic acid. Stearic acid, if 
present at all, occurs in very small amount. Oleic and linolic acids make up 
the liquid fatty acid, the latter acid constituting, according to Lewkowitsch, 
upward of 30% of the total fatty acids. 



1 



536 FOOD INSPECTION AND ANALYSIS. 

U. S. Standards. — Cottonseed oil is the oil obtained from the seeds of 
cotton plants and subjected to the usual refining processes; is free from 
rancidity, has a refractive index (25° C.) not less than 1.4700 and not 
exceeding 1.4725; and an iodine number not less than 104 and not 
exceeding no. 

" Winter-yellow " cottonseed oil is expressed cottonseed oil from which 
a portion of the stearin has been separated by chilling and pressure, and 
has an iodine number not less than no and not exceeding 116. 

Cottonseed Stearin. — This product, used in lard substitutes, is obtained 
as a by-product in the manufacture of winter-yellow cottonseed oil. It 
is a light yellow fat, resembling butter in consistency. 

Hydrogenated Cottonseed Oil is now often used in place of animal 
or cottonseed stearin as a stiffener for lard. Under various trade names, 
unmixed, it is a popular substitute for lard. 

Bechi's Silver Nitrate Test. — Hehner's Modification. — Two grams of 
silver nitrate are dissolved in 200 cc. of 95% alcohol free from aldehyde, 
40 cc. of ether are added, and the reagent made very slightly acid with 
nitric acid. 

In applying the test, a small quantity of the melted fat or oil is mixed 
in a test-tube with half its volume of the above reagent, and the tube is 
immersed in boiling water for fifteen minutes. With proper precautions 
the presence of cottonseed oil is indicated by a more or less strong reduc- 
tion of the silver, while an oil or fat free from cottonseed oil causes no 
appreciable reduction. 

Certain oils free from cottonseed that have become rancid or decom- 
posed, as well as fats that have been subjected to a high temperatirre, 
sometimes show a slight reduction with Bechi's test. In cases of doubt 
it is well to apply the test on the fatty acids as follows : 

Milliau's Modification of Bechi's Test.^ — Heat 20 grams of the sample 
with 30 cc. of alcoholic potash solution (20% potassium hydroxide in 
70% alcohol), shaking at intervals till saponification is complete. Con- 
tinue the heating for some minutes afterward until the alcohol is driven off, 
and dissolve the soap in 250 cc. of hot water. Add a slight excess of 10% 
sulphuric acid, and wash the separated fatty acids three times by decanta- 
tion with water. Then proceed with a portion of the fatty acids as in Bechi's 
test. 



* Moniteur Scientifique, 1888, 366. 



^ 



OILS AND FATS. 537 

The Halphen Test.* is much more delicate and dependable than 
either of the preceding, as little as 2% of cottonseed oil being rendered 
apparent in olive oil. A mixture is made of equal volumes of amyl alcohol 
and carbon bisulphide in v^hich 1% of sulphur has been dissolved. From 
3 to 5 cc. of melted fat are mixed with an equal volume of the above reagent 
in a test-tube, loosely stoppered v^ith cotton, and heated in a bath of boiling 
saturated brine for fifteen minutes. If cottonseed oil is present, a deep- 
red or orange color is produced. In its absence little or no color is de- 
veloped. 

Previous heating of the oil diminishes the delicacy of the Halphen 
test, and Holde and Pelgry | state that if cottonseed oil has been heated 
at 250° C. for ten minutes, it v^ill fail to respond to the test. Fulmer | finds 
that it is necessary to heat to 265 to 270° to render it wholly inactive to 
the test. Hydrogenation also destroys the constituent that produces the 
color. The influence of feeding hogs cottonseed meal on the reaction 
with the lard is discussed on p. 579. 

Gastaldi § finds that it is the pyridin bases in amyl alcohol that render 
it useful. The test can be made by heating 5 cc. oil, 4 cc. carbon bisul- 
phide containing 1% of sulphur, and i drop of pyridin for from 15 minutes 
to one hour in a water-bath. 

Kapok oil, from two species closely related to cotton, also responds to 
the Halphen test, but is a rarity on the American market. 

SESAME OIL. 

Sesame, benne, teel or gingilli oil is pressed from the seeds of common 
sesame (Sesamum Indicum) and black sesame (S. radiatum). These plants 
are native to southern Asia, but are now cultivated in nearly all tropical 
countries. The larger portion of commercial sesame oil is manufactured 
in England, France, Germany, and Austria. 

The seeds are flattened pear-shaped, 2 to 3 mm. long; those of S. 
Indicum are yellow to brown, while those of S. radiatum are dark brown to 
nearly black. They contain 35 to 60% of oil. The seeds are commonly 
subjected to cold pressure once, and afterwards twice pressed when warm, 
thus yielding three grades of oil. 

* Jour, pharm. chim., [6] 6, 1899, p. 390. 
t Jour. Soc. Chem. Ind., 18, 1899, p. 711. 
t Jour. Amer. Chem. Soc, 24, 1902, p. 1149. 
§ Chem. Ztg., 35, 191 1, p. 688. 



538 FOOD INSPECTION AND ANALYSIS. 

Sesame oil consists of the glycerides of oleic, stearic, palmitic, and lino- 
lie acids together with phytosterol, sesamin, and sesamol, the latter causing 
the red color in the Baudouin test. It is golden yellow in color, free from 
odor, and possesses a delicate and characteristic flavor, on account of which 
the highest grades are by some considered equal to olive oil as a condiment. 
It is accordingly sold to some extent as an edible oil. It was formerly 
used as an adulterant of olive oil, but has of late years been largely dis- 
placed by cheaper oils for purposes of adulteration. When cooled to 
—3° C, sesame oil congeals to a yellowish-white mass. 

For range of constants see pages 528 and 529. 

U. S. Standards. — Refractive index (25°) 1.4704 to 1.4717; iodine 
number 103 to 112. 

Adulterants to be looked for in sesame oil are cottonseed, poppyseed, 
corn, and rape oils. 

Tocher's Test.* — One gram of pyrogallic acid is dissolved in 15 cc. 
of concentrated hydrochloric ucid mixed with 15 cc. of the sample in a 
separatory funnel. After standing for a minute, the aqueous solution is 
withdrawn and boiled. If sesame oil is present, the solution shows a red 
coloration by transmitted, and a blue by reflected, light. 

Baudouin's Test.f — Dissolve o.i gram of cane sugar in 10 cc. of hydro- 
chloric acid (specific gravity 1.20) in a test-tube, and shake thoroughly 
with 20 grams of the oil to be tested for one minute. Then allow the 
mixture to stand. The aqueous solution quickly separates from the oil, 
and in the presence of 1% or more of sesame oil wfll be colored deep red. 

Certain pure Tunisian and Algerian olive oils have been found to 
cause a slight coloration with this test, but of a different shade from sesame. 
Zega and Todorovic J state that 5 cc. of the colored solution made up to 
25 cc. and shaken loses its color in five to eight minutes, while the colored 
solution in the case of olive oil containing 3% of sesame oil required thirty 
minutes. Moreover, if the test is applied to the fatty acids, no coloration 
in the case of olive oil is produced, while with sesame the color is the same 
as with the oil. 

Villavecchia and Fabri? Test.§ — This test was suggested on account 
of the fact that the color reaction in the Baudouin test was attributed to 
the agency of the levulose produced by the inversion of the sugar by 

* Chem. Ztg. Rep., 5, 1891, p. 15. 

t Zeits. angew. Chem., 1892, p. 500. 

J Chem. Ztg., 33, 1909, p. 103. 

§ Jour. Soc. Chem. Ind., 1894, PP- ^3~^9- 



I 

I 



OILS AND FATS. 539 

hydrochloric acid. As furfurol is the chief product of the reaction between 
levulose and hydrochloric acid, it was substituted as follows: Dissolve 2 
grams of furfurol in 100 cc. of 95% alcohol, and shake o.i cc. of this solu- 
tion in a test-tube with 10 cc. of the oil to be tested and 10 cc. of hydro- 
chloric acid (specific gravity 1.20) for half a minute. The aqueous 
layer, on settling out, will be colored deep red, if sesame is present. 

Or 0.1 cc. of the alcoholic furfurol solution is mixed with 10 cc. of 
oil and i cc. of hydrochloric acid in a separatory funnel, shaken well, 
and the separation aided by the addition of chloroform, which causes 
the aqueous layer, showing color with sesame oil, to float. 

Sesame oil that has become rancid or has been exposed to air for some 
time gives a blue or green color. 

RAPE OIL. 

Rape or colza oil is expressed from the seeds of the Brassica or rape 
plant, of which there are three principal varieties. Brassica napus, B. cam- 
pestris, and B. rapa, one or another of which are cultivated in nearly 
every country of Europe, excepting Greece. Large amounts are also 
grown in India and China. The seeds are small, round grains, from 
2 to 2.5 mm. in diameter, yielding from 35 to 45 per cent of oil. 

In the process of preparation the seeds are first crushed, and the oil 
removed by pressing or extraction. The crude oil is of a brownish 
yellow color, and when fresh is almost free from taste and smell, so that 
it serves, when cold pressed, as an edible oil, or an adulterant of such 
oils. It develops a disagreeable and peculiar taste and odor on long 
standing, due to the presence of certain albuminous and mucilaginous 
substances which it contains. These may be removed by refining, usually 
by treatment with sulphuric acid, but the refined oil has an unpleasant 
taste and odor. 

The characteristic fatty acids of cruciferous oils (rape, mustard, and 
charlock) are erucic and rapic. Rape oil also contains arachidic acid 
0.36-1.61%, Archbutt). Oleic acid occurs in large amount, saturated 
acids only to the extent of about 1% (Tolman and Munson). The pres- 
ence of sulphur, formerly thought to be characteristic of cruciferous oil, 
is accidental. Cruciferous oils properly refined contain none, while other 
oils extracted by carbon bisulphide may contain an appreciable amount. 

Detection. — Rape and other cruciferous oils are said to be used as 
adulterants of edible oils although definite evidence appears to be meagre. 



540 FOOD INSPECTION AND ANALYSIS. 

They are detected by the presence of erucic acid * as well as by their low 
saponification numbers. The Palas test has been found unreliable. Con- 
stants and variables are given on pages 528 and 529. 

MUSTARD OIL. 

The fixed oil of mustard is a by-product expressed from the seeds of 
black, white, and brown mustard {Brassica nigra, B. alba, and B. Besseri- 
ana) in the process of preparation of mustard flour as a spice. The seeds 
contain 25 to 35% of oil. 

Black mustard oil is brownish yellow in color, having a mild flavor, 
and an odor but slightly suggestive of mustard. White mustard oil is golden 
yellow and has a somewhat sharp taste. 

Mustard oil resembles rape oil in composition, containing glycerides 
of erucic and probably rapic acid and having a low saponification number. 

CHARLOCK OIL. 

Wild mustard, produced in enormous quantities in American grain 
fields, consists of charlock {Brassica arvensis) and brown mustard (B. 
Besseriana) in various proportions (page 476). The following results were 
obtained by Bailey and Burnett f on the oil expressed from the seeds 
of charlock separated from American screenings and shown by botanical 
analysis to be 98 and 99% pure : 

Specific gravity i5Vi5° 0.9221 

Refractive index, 25° i -4734 

Saponification No 182.9 

Iodine No. (Hanus) 121. i 

Insoluble acids and unsaponifiable 95 .3 

Soluble acids 0.0 

Mean mol. wt. of ins. acids 339 . i 

Liquid acids, per cent. 89 . 3 

Liquid acids, iodine No 126.0 

Solid acids, per cent 3.1 

Solid acids, iodine No 



* Tortelli and Fortini, Gaz. chim. ital., 41, I, 1911, p. 173. Biazzo and Vigdorcik 
Ann. chim. appl., 6, 1916, p. 185. 

t Jour. Ind. Chem., 8, 1916, p. 429. 



OILS AND FATS. 541 

The figures for iodine number given in the foregoing table are higher 
than reported by Grimme (102.6), due probably to the freedom of the seed 
from brown mustard and other impurities. Data on the constants of brown 
mustard are lacking owing to the confusion caused by assigning lO the 
Russian species or true brown mustard {B. Besseriana) the specific name 
B. juncea which has been shown to belong only to the Indian Species 
known as "rai." 

CORN OR MAIZE OIL. 

Corn oil is derived from the kernels of Indian corn or maize {Zea Mays) 
which contain from 3 to 7.5% of fat soluble in ether or calculated to the germ, 
as separated from the kernels, from 18 to 30%. Whether the corn is 
designed primarily for the manufacture of mill products, starch, glucose, 
or alcohol the best approved practice at the present time is to separate the 
germs mechanically and from them obtain the oil by pressure. E. H. S. 
Bailey * states that in the manufacture of starch and glucose the germ 
is removed from the grain after soaking in sulphurous acid, which gives a 
high yield, but induces rancidity in the oil even before extraction, while, by 
the dry process as followed in the corn mills, an oil is obtained which 
requh-es little refining. Formerly the oil was separated from the vats in 
the distilling industry. 

Nature and Composition. — When obtained from damaged grain or as 
a by-product from the starch, glucose, or distilling industries the unrefined 
oil may be high, both in total and volatile fatty acids, but when prepared 
from sound grain by the dry process it is low in acidity and has an agreeable 
flavor suggestive of the grain. Such oil is well suited for salads and cook- 
ing, also after hydrogenation as an ingredient of butter and lard sub- 
stitutes. The color is a more or less decided yellow. The oil is semi- 
drying. 

The solid fatty acids, amounting to about 7%, (4-55% Hopkms; 7.44% 
Tolman and Munson) consist largely or entirely of palmitic acid. Stearic 
acid appears to be absent. Two liquid acids are present, linolic (29%) and 
oleic (64%). The amount of unsaponifiable matter is high (1.2-2.9%). 

It is claimed by Hopkins, t by Hoppe-Seyler, and others, that corn oil, 
unlike most vegetable oils, contains cholesterol. Olive oil was long supposed 
to be unique as a vegetable oil in containing this substance. Hopkins, 
on the assumption that cholesterol occurs in corn oil, suggested that a test 

* U. S. Dept. Agric. Yearbook, 1916. 

t Jour. Amer. Chem. Soc, 20, 1898, p. 948. 



542 FOOD INSPECTION AND ANALYSIS. 

for com oil as an adulterant of certain vegetable oils lay in the identification 
of cholesterol. 

Gill and Tufts * claim that, while the alcohol of com oil is not phytos- 
terol, neither is it cholesterol, but a third substance, known as sitosterol,! 
occurring in wheat and rye. 

There are no color reactions identifying corn oil as such. Its pres- 
ence in other oils is indicated only by its influence on the various con- 
stants, the iodine number and refractometric reading especially being 
much higher than those of other edible oils. For range of constants and 
variables see tables pages 528 and 529. 

PEANUT OIL. 

Peanut or arachis oil is obtained from the seeds of the Arachis hypo- 
gcBa (peanut, ground nut, or earth nut) cultivated in most tropical coun- 
tries, notably in South America, China, India, and Japan. The plant 
is a creeping herb, developing its blossoms in the axes of the leaves. The 
flower buds grow down into the earth, where the fruit is ripened, forming 
the well-known peanuts of commerce. The shelled nut contains nearly 
50% of fat. 

The oil is extracted by pressure, the first cold-drawn oil being practically 
colorless, and possessing a pleasant taste suggestive of kidney beans. It 
is especially adapted for use as a salad or table oil. A second pressure of 
the moistened residue from the first yields an inferior oil, yellowish in color, 
also somewhat used for edible purposes, and sometimes commercially 
called " butterine oil." 

Composition. — The insoluble fatty acids consist chiefly of arachidic 
and lignoceric acids which together form about k^{ . Stearic and palmitic 
acids, if present at all, are in small amount. The chief liquid fatty acid 
is oleic. Linolic (6%) is also present. The presence of hypogeeic acid is 
in dispute. 

U. S. Standards.— 'Refractive index (25°) 1.4690 to 1.4707; iodine 
number 87 to 100. 

Adulterants of peanut oil are cottonseed, poppyseed, rape, and sesame 
oils. It was itself formerly used to a considerable extent as an adulterant 
of French and Italian olive oils but now ranks as a substitute. 



* Ibid., 25, IQ03, p. 251. 

t Burian, Monatsh. Chem., 18, 1897, p cct. 



OILS AND FATS. 543 

Detection. — Peanut oil, when pure or nearly pure, may as a rule be 
readily distinguished from other common oils by its constants (pages 528 
and 529), the presence of arachidic acid, and negative reactions with color 
tests. When present in olive oil chief dependence for its detection must be 
placed on the Renard test for arachidic acid, especially in its modified 
forms or on the Bellier test. 

The Renard Test * has long been in use for detecting and estimating 
peanut oil in mixtures. In its original form this test did not give enturely 
satisfactory results, and earlier led to some erroneous conclusions. In 
recent years, however, it has been so modified and improved as to be 
capable of quite positive results when carefully carried out. While 
arachin is said to occur in minute traces in olive oil, its presence is not 
sufficiently marked to interfere with the use of the Renard method in 
detecting any decided admixture of peanut oil. 

Tolman Modification.^ — Saponify 20 grams of the sample in a 250-cc. 
Erlenmeyer flask with 200 cc. of a solution of 40 grams of potassium 
hydroxide in i liter of 95% redistilled alcohol. Neutralize with dilute 
acetic acid, using phenolphthalein as an indicator, and wash into a 500-cc. 
flask containing a boiling mixture of 100 cc. water and 120 cc. 20% 
solution of lead acetate. 

Boil for a minute and cool the contents of the flask by immersing 
in cold, or, preferably, ice water, whirling the flask occasionally so that 
the soap when cold adheres to the sides of the flask. The water and 
excess of lead acetate can then be poured out, leaving the soap in the 
flask. Wash by shaking and decantation, first with cold water and 
then with 90% alcohol. Add 200 cc. of ether, cork the flask, and allow 
to stand with occasional shaking till the soap is disintegrated after which, 
boil on a water-bath under a reflux condenser for five minutes. Cool 
the soap solution down to a temperature between 15° and 17°, and allow 
it to stand for about twelve hours. 

Filter and thoroughly wash the precipitate with ether, after which the 
soap in the filter is washed back into the original flask with a stream of 
hot water acidulated with hydrochloric acid. 

Add an excess of dilute hydrochloric acid, partially fill the flask with 
hot water, and heat until fatty acids form a clear oily layer. Fill the flask 
with hot water, allow the fatty acids to harden and separate from the 



* Compt. rend., 73, 1871, p. 1330. 

t U. S. Dept. of Agric. Bur. of Chem., Bui. 65, 1902, p. 2^. 



544 FOOD INSPECTION AND ANALYSIS. 

precipitated lead chloride, wash, drain, repeat washing with hot water, 
and dissolve the fatty acids in loo cc. of boiling 90% by volume alcohol. 
Cool to 15° C, shaking thoroughly to aid crystallization. 

From 5 to 10% of peanut oil can be detected by this method, as it 
effects a complete separation of the soluble acids from the insoluble, which 
interfere with the crystallization of the arachidic acid. Filter, wash the 
precipitate twice with 10 cc. of 90% alcohol, and then with 70% alcohol. 
Finally dissolve off the precipitate with boiling absolute alcohol, evapo- 
rate to dryness in a tared dish, dry and weigh. To the weight add 0.0025 
gram for each 10 cc. of 90% alcohol used in the crystallization and wash- 
ing, if done at 15° C, and 0.0045 gram for each 10 cc. if done at 20°. The 
approximate amount of peanut oil is found by multiplying the weight 
of arachidic acid by 20. 

Arachidic acid crystals thus obtained should be examined microscop- 
ically. The melting-point should lie between 71° and 72° C. 

W. B. Smith * found that recrystallization is essential for the detec- 
tion of peanut oil in solid fats. 

The Kerr Modification. -\ — Heat to boiling 20 grams of the sample 
with 200 cc. of 95% ethyl alcohol, add while boiling 10 cc. of potassium 
hydroxide solution (ico grams in 100 cc. of water), and when saponifica- 
tion is complete neutralize with a solution of glacial acetic acid in 95% 
alcohol (i : 3). Add 50 cc. of magnesium acetate solution (10 grams of 
the salt in 100 cc. of water and 100 cc. of 95% alcohol) and heat again to 
boiling. Cool to room temperature with occasional shaking and keep in a 
refrigerator at 10° to 15° C. over night, filter, wash the precipitate twice 
with 50% alcohol, and three times with water, then return to the saponi- 
fication flask. Add 100 cc. of hot distilled water and sufficient sulphuric 
acid (i : 3) to decompose the magnesium salts. Heat until the separated 
acids form a clear layer, cool until they solidify, and pour off the acid solu- 
tion. Add to the fatty acids 100 cc. of hot water and when they have melted, 
cool and decant off the liquid as before. Drain, dissolve in 100 cc. of 90% 
(by volume) alcohol, and crystallize as in the Tolman modification. 

Methods of J. 'QQ\^eT.X~Qualitative Test. — Saponify i gram of the 
oil with 5 cc. of an alcoholic potash solution containing 85 grams potas- 
sium hydroxide per liter of strong alcohol, conducting the saponification 
in a small Erlenmeyer flask on the water-bath. After saponification, 

* Jour. Amer. Chem. Soc, 29, 1907, p. 1756. 
t Jour. Ind. Eng. Chem., 8, 1916, p. 904. 
X Ann. chim. anal,. 1899, 4, p. 49. 



OILS AND FATS. 545 

boil for two minutes, neutralize with dilute acetic acid, using phenoiphtha- 
lein as an indicator, and cool by setting the flask in water at a temperature 
of from 17° to 19°. After a short time, a precipitate nearly always comes 
down. Then add to the solution 50 cc. of 70% alcohol, containing 1% 
by volume of strong hydrochloric acid (specific gravity 1.20). Cork the 
flask, shake vigorously, and again cool by setting the flask in the above 
cooling-bath. In the absence of a precipitate, the oil may be pronounced 
free from peanut. If 10% or more of peanut oil is present, a more or less 
characteristic precipitate forms, and often with less than 10% a cloudiness 
in the solution is perceptible after standing between 17° and 19° for half ^n 
hour. Pure olive oil remains perfectly clear as a rule. 

A few varieties of olive oil from Tunis especially high in solid fat 
acids, as well as cottonseed oil and sesame oil, give similar turbidity on 
the addition of the 70% alcohol. To distinguish between these ofls and 
peanut oil, heat the mixture on the water-bath till complete solution 
takes place, and again cool to 17° to 19°. In the case of peanut oil the 
cloudiness or precipitate again occurs to the same extent as before, while 
in the other cases the solution should remain clear or nearly so. 

Quantitative Determination. — Saponify 5 grams of the oil with 25 cc. 
of the above alcoholic potash solution in a 250-cc. Erlenmeyer flask, 
neutralize exactly with acetic acid, and cool quickly in water. After 
standing an hour, pour upon a 9-cc. filter and wash the precipitate with 
70% alcohol containing 18% by volume of hydrochloric acid, the tem- 
perature of the solution being not less than 16° nor more than 20°. Con- 
tinue the washing till the wash water no longer shows turbidity when 
diluted with water. 

Dissolve the precipitate in 25 to 30 cc. of hot 95% alcohol, dilute with 
water until the alcohol is 70%, let stand in water at 20°, filter, wash with 
70% alcohol, dry at 100°, and weigh. 

Bcllier states that he has recognized with certainty as small an admix- 
ture as 2% of peanut oil by this method. 



SOY OIL. 

This oil, prepared from the seed of Soja hispida, is of comparatively 
recent introduction in the Occident, although long extensively used in China 
and Japan both for food and technical purposes. 

The seed contains about 20% of a semi-drying oil of which somewhat 
more than half is expressed by the methods employed. Extraction yields 



546 



FOOD INSPECTION AND ANALYSIS. 



a larger amount but is practiced chiefly with damaged beans the cake of 
which is not suited for cattle food. The edible oil is commonly filtered 
through fuller's earth. 

Composition. — Matthes and Dahl * have reported in soy oil 15% of 
palmitic acid and 80% of liquid fatty acids, the latter consisting of 56% 
of oleic acid, 19% of linolic acid, and 5% of linolenic acid, calculated in 
percentage of the oil. Because of the presence of linolenic acid, the oil 
responds to the hexabromide test. 

Keimatzu f found 12% of saturated fatty acids and 80% of unsatu- 
rated fatty acids, about half of the latter consisting of an isomer of linolic 
acid, the remaining half containing linolic and oleic acids. The same 
author isolated phytosterol, but could not find a trace of stigmasterol, which 
Matthes and Dahle claim is present. 

Detection. — Quite widely different constants for soy oil have been 
reported indicating that the product is far from uniform, due to the pro- 
cess employed and other causes. The iodine number is higher than that 
of most edible oils, approaching that of linseed. 

Washburn J has determined the values for 202 samples prepared by 
him by hot pressure (or in a few cases by carbon tetrachloride extraction) 
from soy beans grown in various states representing 45 varieties, the range 
being as follows : 





Specific Gravity 
at 15.5° C. 


Refractive Index 
at 25° C. 


Saponification 
No. 


Iodine 
No. (Hanus). 


Maximum 


0.9310 
0.9207 


1-4750 
I. 4710 


197.4 
190. 1 


141-9 
II5-S 


Minimum 





The range of values by all observers appears on pages 528 and 529. 

Settimi Test. § — The following color test has been proposed: Shake 
vigorously so as to form a thorough emulsion 5 cc. of the oil with 2 cc. of 
chloroform and 3 cc. of 2% aqueous uranium nitrate solution. With 
soy oil the color is intense lemon yellow, with peanut, sesame, and corn 
oil, white, and with olive oil, slightly green. Certain olive oils give a 
slight yellowish color but do not give the seed oil reactions which soy does 
in a marked degree. 



* Arch. Pharm., 240, 191 1, p. 424. 

t Chem. Ztg., 35, igii, p. 839. 

t N. Dak. Agr. Exp. Sta. Bui., 118, 1916. 

§ Gior. farm, chim., 61, p. 495. 



OILS AND FATS. 547 



LINSEED OIL. 

Brief mention should be made of linseed oil. Although not usually- 
classed with edible fats, the oil is used in pharmacy and the cake, either 
old process (pressed) or new process (extracted) is a valuable cattle food. 

Linseed oil is a typical drying oil with a high iodme number, being com- 
posed chiefly of the unsaturated acids, linolenic, linolic and oleic, named 
in the order of the amount present (Fahrion). Constants are given on 
pages 528 and 529. 

POPPYSEED OIL. 

This oil is obtained from the seeds of the opium poppy {Papaver 
somniferum), native in the countries east of the Mediterranean, and cul- 
tivated extensively for opium and for oil in all parts of Europe, Asiatic 
Turkey, Persia, Egypt, India, and China. Most of the oil of commerce 
comes from France and Germany. 

There are two chief varieties of poppy, the black (P. nigrum) and 
the white {P. album), the finest oil being produced from the white. The 
seeds are somewhat flattened in form and kidney-shaped, containing from 
40% to 50% of oil. 

The oil is obtained by crushing the seeds and applying pressure. 
The best grade of cold-drawn oil is pale yellow in color, possessing a 
pleasant taste when fresh, and being practically free from odor. Lower 
grades shade into deeper yellow and even reddish color, possessing a 
strong taste and odor. 

Poppyseed oil is much used in Europe as a table ofl, and does not readily 
turn rancid. It has been used to some extent as an adulterant of olive oil. 
and is itself not infrequently adulterated with sesame oil. 

Composition.— The solid fatty acids (6.67 Tolman and Munson) consist 
presumably of palmitic and stearic acids. The liquid acids pxcording to 
Nazura and Grussner are composed of 65% linolic acid, 30% oleic acid, 
and 5% linolenic acid. 

Detection.— The refraction and iodine number are high as they are also 
in soy bean and sunflower oils (pp. 528 and 529). 

SUNFLOWER OIL. 

Sunflower oil is derived from the seed kernels of the plant of the 
same name {Helianthus annuus), originally grown in Mexico, but now 



548 



FOOD INSPECTION AND ANALYSIS. 



cultivated most extensively on a commerical scale in southern Russia, 
Hungary, and the Orient. 

The v^hole seed, or rather dry fruit, has, according to S. M. Babcock * 
the following composition: 





Air-dry. 


Dried. 


Water 


12.68 
3.00 
15.88 
29. 21 
18.71 
20.52 

100.00 


3-43 
18.19 

33-45 
21.43 
23-50 


Ash 


Albuminoids (NX 6. 25).. 
Crude fiber 


Nitrogen-free extract. . . . 
Fat (ether extract) 


100.00 



The decorticated seed contains as high as 50% or more of oil. 

In preparing the oil the decorticated seed is crushed and subjected to 
either hot or cold pressure. 

Sunflower oil is pale yellow in color, has a mild, pleasant taste, and 
is nearly free from odor. The cold-drawn oil is the variety most used for 
edible and culinary purposes in Russia, and in Europe as an adulterant 
of olive oil. 

Composition. — The liquid fatty acids of sunflower oil consist for the 
most part of linolic, but little oleic acid being found. The constants as 
given on pages 528 and 529 show that the oil resembles soy bean and 
poppyseed oils. 

ROSIN OIL. 

Rosin oil is prepared by the distillation of common rosin, and is an 
alleged adulterant of olive oil, 

Lieberman-Storch Test. — Shake i to 2 cc. of the sample with acetic 
anhydride while warming. Cool, remove the anhydride by a pipette, and 
add a drop of sulphuric acid (specific gravity 1.53). Rosin oil gives a fugi- 
tive-violet color.f 

Cholesterol also responds to this color reaction. 

Renard's Test for Rosin Oil. — Prepare a solution of stannic bromide 
by allowing dry bromine to fall drop by drop upon tin in a dry, cool flask, 
and dissolving the product in carbon bisulphide. 



* The Sunflower Plant, its Cultivation, Composition, and Uses. 
Div. of Chem., Bui. 60, p. 18. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 32. 



U. S. Dept. of Agric, 



OILS AND FATS. 549 

Add a drop of this reagent to i cc. of the oil. In presence of rosin 
oil a violet color will be produced. 

Polarization Test for Rosin Oil.* — The oil is dissolved in definite 
proportion in petroleum ether, and polarized in a 200-mm. tube. Rosin 
oil polarizes from +30 to +40 on the cane sugar scale, vi^hile other oils 
have a reading between +1 and — i. 

COCOANUT OIL. 

Cocoanut oil is the fa- expressed from the kernels of the cocoanut 
or fruit of the cocoa palm {Cocos nucifera), indigenous to the South Sea 
Islands and to the East-Indian archipelago, but grown in many tropical 
countries. 

The oil is prepared from either the fresh or dried kernels (copra). 
The method employed in India, Ceylon, and Cochin depends on pounding 
the fresh kernels, boiling with water, and skimming off the fat. The fat 
is obtained from copra by pressing either in the country of origin or in 
Europe or America. 

While formerly cocoanut oil was used in the Occident chiefly for soap 
making or in pharmacy, since the beginning of the Great War it has come 
into very extensive use in the manufacture of vegetable or nut butter. 

Nature and Composition. — Cold drawn Malabar oil is of a greenish 
color and is used chiefly by the natives as food. Edible cocoanut oil of 
commerce is white with a mild taste and characteristic odor. Formerly 
it was regarded as specially prone to become acid and rancid, but it is now 
known that if properly made from sound material the fat has good keeping 
qualities. 

Cocoanut and palm kernel oils are characterized by their high content 
of lauric and myristic acids and consequent high Polenske numbers. They 
also contain considerable amounts of caproic, caprylic, and capric acids 
(but no butyric acid), hence the higher Reichert-Meisl numbers than other 
oils and fats excepting butter fat. 

Detection. — The constants most valuable in the detection of cocoanut 
oil in addition to the Reichert-Meissl and Polenske numbers, are the 
saponification number, and the iodine number as shown in the table on 
pp. 528 and 529. The iodine number (8-9.5) is strikingly low, although 
oil from the rind, according to Richardson, f runs as high as 40. 



* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 32. 
t Jour. Ind. Eng. Chem., 3, 191 1, p. 574. 



550 FOOD INSPECTION AND ANALYSIS. 

According to Andes,* crystals of cocoanut oil appear under the micro- 
scope as a thick network of long needles. Hinks f distinguishes cocoanut 
oil from butter fat by the needle-shaped crystals which separate out from 
alcohol. 

PALM KERNEL OIL. 

This oil, also known as palm nut oil, is pressed from the dried endo- 
sperm of the seed of Elais Guineensis and is radically different from palm 
oil which is prepared from the fruit pulp. The tree is indigenous to 
West Africa where natives gather the fruit in large quantities and separate 
the endosperm from the shell by hand. The oil was formerly expressed at 
Marseilles but more recently the industry has been confined chiefly to 
Hamburg. 

Palm kernel oil resembles closely cocoanut oil in physical and chemical 
properties and serves the same purposes. The better grades are used in 
butter and lard substitutes while the inferior grades are made into soap. 

Palm oil is not classed with the edible fats although being of a deep 
orange color it has been added to butter substitutes for coloring (p. 565). 

COCOA (CACAO) BUTTER. 

This preparation is a by-product in the manufacture of cocoa, being 
removed by pressure from the crushed and ground cocoa nibs. The fat 
in cocoa beans usually is over 50%. The expressed fat is yellowish white, 
extremely hard, has a pleasant taste and an odor suggestive of chocolate. 
It keeps a long time without turning rancid. In composition it consists 
of the glycerides of stearic, palmitic, and oleic acids, with small amounts 
of the glycerides of arachidic and linolic acids. 

It is in demand for pharmaceutical purposes and for adding to the choco- 
late used in coating candies. 

It is subject to adulteration with paraffin, tallow, stearins, hydrogenated 
oils, and various tropical fats. 

TALLOW. 

The rendered fats of various animals, especially the cow and sheep, 
constitute what is generally known as tallow. The untreated fatty tissues 
are more properly known as suet, the tallow being the clear fat separated 
entirely by heat from the cellular material. 

* Vegetable Fats and Oils, London, 1897. 
t Analyst, 32, 1907, p. 160. 



OILS AND FATS. 551 

Tallow consists almost entirely of olem, palmitin, and stearin. Mutton 
tallow is usually, but not always, harder than beef tallow. 

Excepting in the manufacture of material for oleomargarine, wherein 
the heart and caul fats of beef are almost exclusively used, the fats from 
different parts of the animal are not, as a rule, separated. 

Fresh tallow has very little free fatty acid, but when it becomes rancid, 
the fat contains sometimes as high as la'^o oi free acid, reckoned as oleic. 

Tallow is of chief interest to the food analyst in connection with its 
use as an adulterant of lard. 

BUTTER. 

Nature and Composition. — Butter is the product obtained by the 
churning of cream or milk, whereby the fat particles are caused to adhere 
together into a compact mass, inclosing a certain portion of the casein, the 
excess of milk serum being subsequently largely removed by washing and 
mechanical working. 

Butter Fat is of extremely complex composition, containing a larger 
variety of glycerides than any other fat. Besides the glycerides of oleic, 
palmitic, and stearic acids, the usual glycerides of the insoluble or fixed 
fatty acids found in most fats, butter contains, notable quantities of the 
glycerides of a number of the volatile fatty acids, chief among which are 
butyric, caproic, capric, caprylic, lauric and myristic, to which are due 
in part its distinctive taste, and which by exposure to light and air readily 
become decomposed into the free acids. 

The process of separation of butter fat into its component glycerides 
is a matter of extreme difficulty, and results obtained by different chemists 
vary widely. Separation has been attempted by fractional distillation, 
by methods depending on the difference in chemical affinity of the various 
acids, and on the difference in solubility of the various lower homologues 
in water at different temperatures. 

According to Browne,* the composition of butter fat is as shown in 
table on page 552. Holland, Reed and Buckley t by then* improved 
method find 7% to 22% of stearic acid. 

The fatty acids are not all combined as simple triglycerides. Amberger, J 
for example, has isolated palmito-distearin and stearo-dipalmitin. 



* Jour. Amer. Chem. Soc, 21, 1899, pp. 612, 807 and 975 

t Jour. Agric. Res., 6, 1116, p. loi. 

X Zeits. Unters. Nahr. Genussm., 26, 1913, p. 3802. 



552 



FOOD INSPECTION AND ANALYSIS. 



Acid. 



Dioxystearic 

Oleic 

Stearic 

Palmitic. . . . 
Myristic. . . . 

Laurie 

Capric 

Caprylic. . . . 
Caproic .... 
Butyric. . . . 

Total . . . , 



Fatty Acids. 



I.OO 
32.50 
1-83 
38.61 
9.89 
2.57 
0.32 
0.49 
2.09 
5-45 

94-75 



Equivalent 
Triglycerides. 



I .04 

33-95 
1. 91 

40.51 
10.44 

2.73 
0.34 
0.53 
2.32 
6.23 

100.00 



The constants and variables of butter fat are given on pp. 528 and 

529. 

Effects of Feeding Oil Cakes on the Composition of Butter. — Experi- 
ments have shown that the substance which causes cottonseed oil to 
respond to the Halphen test may pass into the milk fat on feeding cows 
with cottonseed cake, but the substance that gives the Baudouin reaction 
is never carried into the milk on feeding with sesame cake. A number 
of investigators have found that feeding with cocoanut cake raises some- 
what the Polenske number of the milk fat. There is good evidence, 
however, that, while the addition of vegetable oils to butter introduces 
phytosterol, as detected by Bomer's phytosterol acetate test, this substance 
can not be introduced into the milk fat by feeding. These facts should 
be borne in mind in the examination of butter for foreign fats. 



ANALYSIS OF BUTTER. 

Methods of Proximate Analysis.— Drawing the Sample.— Butter 

is particularly difficult to sample owing to the uneven distribution of water 
and salt. If in bulk, as in a creamery previous to packing, or in tubs, 
remove a considerable number of cores with a butter trier to a quart or two- 
pint jar. If in bricks divide a number into quarters by cutting through the 
middle in two directions at right angles to the surface and take one quarter 
of each for the composite sample. 

Guthrie and Ross * have reported results which illustrate the difficulties 



Cornell Agr. Exp. Sta. Bui. 336, 1913. 



OILS AND FATS. 553 

of sampling. Of 51 packages from different sources 9 showed for adjacent 
samples drawn with a trier differences of moisture over 1% and 19 between 
0.5 and 1%. They conclude that the exact composition can only be 
reached by the analysis of a sample made up of many portions taken from 
different parts of the package. 

Preparation of the Sample.— Wiley Method."^— Close the jar and heat at 
about 40° C. in water or in a hot closet until thoroughly melted, taking care 
that no lumps remain. Cool under the tap with continual shaking until 
thoroughly congealed. The sample should be kept in a cold place till 

analyzed. 

Determination of Watet.— Gravimetric Method.— Dry 2 grams of the 
sample to constant weight in a flat-bottomed metal dish heated in a boiling 
water-oven. 

Patrick's Rapid M ethod.-\— This method is especially suited for the 
use of dahymen, inspectors and others not provided with laboratory 

facilities. 

Ten grams of the thoroughly mixed butter are weighed into a 250-cc. 
aluminium beaker, which, together with a glass rod has been previously 
tared, and boiled over (but not in) the flame of an alcohol lamp provided 
with a conical asbestos chimney, holding the beaker by means of a wire 
clamp in a nearly horizontal position to avoid loss from spattering or 
foaming, and whirling constantly to prevent overheating. The rod 
serves to break up lumps of curd which form, thus facilitating the drying. 
The heating should be so conducted as to avoid any considerable dis- 
coloration of the curd. With suitable heating the water may be removed 
in less than 15 minutes, after which the beaker is cooled in water and 
weighed. A balance sensitive to 10 milligrams, such as is used in weighing 
cream for testing by the Babcock method, is sufficiently accurate for weigh- 
ing the butter. 

Gray's Method.X—i. The Special Apparatus, for this method, shown in 
Fig. 100, consists of a flask {A) connected by a close-fitting rubber stopper 
(5) with a graduated tube (C), and this in turn with a condenser jacket 
(£) by a rubber stopper {D). The tube C is closed by a glass stopper, the 
zero mark being the end of the stopper. Each mark of the graduation 
represents 0.02 cc. or, when 10 grams of butter are used, 0.2%. 



* Proc. A. O. A. C, 1887. 

t Jour. Amer. Chem. Soc, 28, 1906, p. 1611; 29, 1907, p. 1126. 

J U. S Dept. of Agric, Bur. of Animal Ind., Circ. 100. 



554 



FOOD INSPECTION AND ANALYSIS. 



2. Process. 



-Weigh lo grams of the well mixed butter on a piece of 
parchment paper 13 cm. square, 
introduce into the flask, and add 
6 cc. of a mixture of 5 parts of 
amyl acetate and i part of amyl 
valerianate, free from water-soluble 
impurities. Connect the apparatus 
as shown in Fig. 100, fill the con- 
denser jacket with cool water to 
within 2.5 cm. of the top, and re- 
move the glass stopper F. Heat 
the flask over a Bunsen burner, 
thus melting the butter and boil- 
ing the water. Watch the con- 
densation of the steam in the 
graduated part of the tube C, and 
do not allow the steam to get higher 
than the 15% mark. In case of 
continued foaming, allow the mix- 
ture to cool, add 2 cc. of the amyl 
reagent, and continue heating. 
After the water in the sample has 
boiled out, the temperature rises 
and the amyl reagent boils, driving 
the last traces of water and water- 
vapor from the flask and bottom 
of the stopper. Some of the amyl 
reagent is carried into the tube C 
with the steam, and some is boiled 
over after the water has been 
driven ofif. 
the tube 
When the 
becomes £ 




This amyl reagent in 
is no disadvantage, 
mixture in the flask 
brown color and all 



the crackling noises in boiling 
Fig. 100.— Gray's Apparatus for the Rapid cease, which usually requires 5 to 
Determination of Water in Butter. g j^inutes, it is safe tO conclude 

that all water has been driven from the flask. 

Disconnect the flask A from the stopper B, place the glass stopper F 



OILS AND FATS. 555 

in the tube C, giving it a turn to insure its being held firmly; invert the 
tube C, first being sure that the mouth of the small tube inside the bulb 
is held upwards, pour the water from the condensing jacket E, and remove 
the jacket. When the tube C is inverted, the water and reagent flow 
into the graduated part of the tube. To separate these and to get the 
last traces of water down into the graduated part, the tube C is held with 
the bulb in the palm of the hand, and the stoppered end away from the 
body, raised to a horizontal position, and swung at arm's length sharply 
downward to the side. This is repeated a number of times until the 
dividing line between the water and reagent is very distinct, and no reagent 
can be seen with the water or vice versa. The tube should then be held 
a short time with the stoppered end downward, and the amyl reagent in 
the bulb agitated in order to rinse down any adhering water. 

The reading should not be taken until the tube and contents have cooled 
so little warmth is felt. When lo grams of butter are used, the percentage 
is read directly at the lower meniscus. 

With butter very low in moisture it may be desirable to use 15 grams, 
and with butter very high, 5 grams. 

Fat. — This may be determined either directly or indirectly. For 
the direct determination, a weighed amount of the sample, from 2 to 3 
grams, is first dried at 100° in sand or asbestos, contained in a thin and 
fragile round-bottomed evaporating-shell (Hoffmeister's Schalchen). If 
desired, the moisture may be determined in this connection by loss in 
weight after drying. The shell is afterwards inclosed in a piece of fat-free 
filter-paper, and crushed in pieces between the fingers in such a manner 
as to avoid loss. The pieces are gathered in a mass,, and folded together 
in the filter-paper to form a packet of a size readily transferable to a 
Soxhlet extractor, in which the fat is removed in the usual manner and 
weighed, after drying, in a tared flask. 

Or, the fat may be indirectly determined by subtracting the sum of 
the water, casein, and ash from 100. 

Casein.— Wiley Method."^ — The residue from the gravimetric deter- 
mination of water is stirred with petroleum ether until the fat is dissolved 
and transferred to a tared Gooch crucible. After thorough washing with 
petroleum ether, the crucible is dried at ico°, cooled, and weighed, thus 
obtaining the casein and ash. The loss on ignition at a dull red heat 
represents the casein. 

* Proc. A. O. A. C, 1887. 



556 FOOD INSPECTION AND ANALYSIS. 

If desired, nitrogen may be determined in the residue after removal of 
the fat with petroleum ether, and casein calculated from the nitrogen, 
using the factor 6.37. 

Ash. — The residue left on the Gooch crucible after ignition, obtained 
as described in the preceding section is the ash. It consists largely of 
salt, which may be calculated from the percentage of chlorine determined 
by titration. 

Milk Sugar and Lactic Acid compose most of the undetermined matter 
remaining after deducting from the total solids the sum of the fat, casein, 
and ash. Determine milk sugar, if desired, in an aqueous extract of the 
butter by Fehling's solution. 

Determination of Salt. — In a tared dish or beaker weigh out about 
5 grams of butter, taking a gram or so at a time from different parts of 
the sample. Add hot water to the weighed part, and after it has melted, 
the contents of the dish are poured into a separatory funnel, shaken and 
allowed to stand till the fat collects at the top, after which the underlying 
aqueous solution is drawn off into an Erlenmeyer flask, leaving the fat 
in the funnel bulb. Hot water is again added, and from ten to fifteen 
extractions are made, using about 20 cc. of water each time, all the water 
being collected in the Erlenmeyer flask. 

A few drops of a solution of potassium chromate are then added for 
an indicator, and the sodium chloride volumetrically determined by a 
standard silver nitrate solution. 

Salted butter contains from 0.5 to 6% of salt. 

U. S. Standard Butter is butter containing not less than 82.5% of 
butter fat. By acts of Congress approved August 2, 1886, and May 9, 
1902, butter may also contain added coloring matter. 

Detection of Foreign Fat.— Preparation of Fat Sample.— The 
butter fat is best obtained by filtering when hot, the sample being melted 
in a beaker on the water-bath. The water, with the curd and salt, will 
settle to the bottom. The clear fat is then filtered at a temperature not 
exceeding 50° C. and subjected to such examination as may be desired to 
determine its purity. 

Examination of the Fat. — This is discussed in detail under the head 
of Distinction of Oleomargarine from Butter, pages 567-571. 

U. S. Standard Butter Fat has a Reichert-Meissl number not less 

40° 
than 24 and a specific gravity not less than 0.905 at — ^ C. 

Detection of Process Butter.— See pages 571-576. 



OILS AND FATS. 557 

Artificial Coloring Matter in butter.— Formerly carrot juice 

and annatto were used almost entirely as butter colors. The carrot fur- 
nished to the farmer a ready means of coloring his dairy butter, and its use 
was long in vogue for this purpose, before the commercial butter colors were 
available. Other vegetable colors, such as turmeric, marigold, saffron, and 
safflower, are said to have been used for this purpose, but, with the possible 
exception of turmeric, the writer is not aware of authentic cases in which 
they have been found in recent years. While annatto as a butter color 
is still in use, it is rapidly giving place to various oil-soluble, azo coal- 
tar colors, which are admirably adapted to the purpose. Butter colors 
are now put on the market in solution in oil, usually cottonseed in this 
country and sesame in Europe. 

Detection. — Martin * devised a general scheme applicable for the 
detection of various colors in butter. His reagent consists of a mixture of 2 
parts of carbon bisulphide with 15 parts of ethyl or methyl alcohol. 25 cc. 
of this solution are shaken with about 5 grams of the butter to be tested, 
and, after standing for some minutes, the mixture separates into two 
layers, of which the lower consists of the fat in solution in the carbon 
bisulphide, while the upper is the alcohol, which dissolves out and is colored 
by the artificial dye employed. If saffron is present, the alcoholic extract 
will be colored green by nitric acid and red by hydrochloric acid and sugar. 

Coal-tar dyes, if present, may be fixed on silk or wool by boiling bits 
of the fiber in the alcoholic extract, diluted with water and acidulated 
with hydrochloric acid. 

Turmeric is to be suspected, if ammonia turns the alcoholic extract 
brown; marigold, if silver nitrate turns it black, and annatto, if on evapo- 
rating the alcoholic solution to dryness and applying to the residue a drop 
of concentrated sulphuric acid, a greenish-blue coloration is produced. 

Turmeric is further tested for in the residue from the alcoholic extract 
as above obtained, by boiling the residue in a few cubic centimeters of 
a dilute solution of boric acid (or a solution of borax acidulated with 
hydrochloric acid), and soaking a strip of filter-paper therein. On drying 
the paper, if it assumes a cherry-red color, turning dark olive by dilute 
alkali, the presence of turmeric is assured. 

Test for Carotin. — This substance, the chief coloring matter of the 
carrot root and according to Palmer and Eckles f of butter, does not impart 



* Analyst, i, p. 70. 

t Jour. Biol. Chem., 16, 1914, p. 191. 



558 FOOD INSPECTION AND ANALYSIS. 

its color to the alcohol layer in Martin's test. Moore * has pointed out 
this exception and shown that with only carotin present the alcohol layer 
in Martin's test remains colorless. If, however, a drop of very dilute 
ferric chloride is added and the test-tube shaken, the alcohol will gradually 
absorb the yellow color from the butter. Care must be taken to avoid an 
excess of ferric chloride, as very little of this reagent will suffice. 

Palmer and Thrum f employ a small crystal of ferric chloride instead 
of the solution and add it to the hot fat after separation from the alcohol 
layer. If the crystal is of the right size the yellow color of carotin is re- 
placed by the green color of ferrous chloride which in turn is removed by 
shaking with lo cc. of methyl or 95% ethyl alcohol, leaving the fat colorless. 

Detection of Annatto. — Treat 2 or 3 grams of the melted and filtered 
fat (freed from salt and water) with warm, dilute sodium hydroxide. 
After stirring, pour the mixture while warm upon a wet filter, using to 
advantage a hot funnel. If annatto is present, the filter will absorb the 
color, so that, when the fat is washed off by a gentle stream of water, the 
paper will be dyed straw color. It is well to pass the warm alkaline filtrate 
two or three times through the fat on the filter to Insure removal of the 
color. 

If, after drying the filter, the color turns pink on application of a drop 
of stannous chloride solution, annatto is assured. . 

Detection of Coal-tar Colors in Butter. — Geislefs Method.X — A few 
drops of the clarified fat are spread out on a porcelain surface and a pinch 
of fullers' earth added. In the presence of various azo-colors, a pink 
to violet-red coloration will be produced in a few minutes. Some varieties 
of fullers' earth react much more readily with the azo-dyes than do others. 
In fact some do not respond at all. When once a satisfactory sample of 
this reagent is obtained, a large stock should be secured of the same variety. 

Low's Method.^ — A small amount of material to be tested is melted 
in a test-tube, an equal volume of a mixture of i part of concentrated 
sulphuric acid and 4 parts of glacial acetic acid are added, and the tube 
is heated nearly to the boiling-point, the contents being thoroughly mixed 
by shaking; the tubes are set aside, and after the acid solution has settled 
out it will have been colored wine-red in the presence of azo-color, while 
with pure butter fat, comparatively no color will be produced. 

* Analyst 11, 1886, p. 163. 
t Jour. Ind. Eng. Chem., 8, 1916, p. 614. 
t Jour. Am. Chem. Soc, 20, 1898, p. no. 
§ Ibid., 20, p. 889. 



OILS AND FATS. 559 

Doolittle's Method for Azo-colors and Annatto.*— The mehed sample 
is first liltercd. Two test-tubes are taken and into each are poured about 
2 grams of the filtered fat, which is dissolved in ether. Into one test- 
tube are poured i or 2 cc. of dilute hydrochloric acid, and into the other 
about the same volume of dilute potassium hydroxide solution. Both 
tubes are well shaken and allowed to stand. In the presence of certain 
azo-dyes, the test-tube to which the acid has been added will show a pink 
to wine-red coloration, while the potash solution in the other tube will 
show no color. If annatto has been used, on the other hand, the potash 
solution will be colored yellow, while no color will be apparent in the 
acid solution, 

Comelison's Test for Artificial Colors.f — Melt 10 grams of the clear, 
dry fat, and shake well in a separatory funnel with 10 to 20 grams of 99,5% 
acetic acid. If the materials are too hot, the fat will dissolve, but at 
about 35° it separates quickly and almost completely. Draw off the clear 
acid, and after noting its color, test by adding to one portion of 5 cc. a few 
drops of concentrated nitric acid, and to another portion a few drops of 
concentrated sulphuric acid. 

Natural yellow butter gives by this test a colorless extract which 
remains colorless on adding nitric acid and becomes a faint pink color 
on adding sulphuric acid. The acid extracts containing annatto, cur- 
cumin, and carrot are various shades of yellow, both before and after 
addition of nitric acid, while with sulphuric acid they take on a pink colora- 
tion on standing, which in the case of curcumin is very decided. Soudan 
I and butter yellow give pink extracts, which remain pink on adding 
the stronger acids, while cerasine orange G, yellow O.B., yellow A.B. 
and certain other coal-tar dyes give extracts of various shades of yellow, 
which on treatment with the heavy acids in some cases remain colorless, 
but in others become pink, while the oil globule which separates remains 
colorless or takes on a pinkish color according to the dye. 

Mathewson's Method J is quite generally applicable although the color 
is somewhat contaminated with sterols. Dilute 30 cc. of the melted fat 
with 120 cc. of low-boiling gasoline and shake out with several portions of a 
mixture of 90 parts of phenol with 10 of water, using first 45 cc. and then 
30 cc. Wash the extract with 2 or 3 portions of gasoline, treat with suf- 
ficient cool, strong potassium or sodium hydroxide solution to dissolve the 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 152. 
t Jour. Am. Chem. Soc, 30, 1908, p. 1478. 
t U. S. Dept. of Agric, Bui. 448, 191 7, p. 6. 



560 FOOD INSPECTION AND ANALYSIS. 

phenol, and shake out with 50 to 100 cc. of ether. Wash the ether with 
caustic alkali solution to remove all phenol and finally with water, then 
evaporate or treat further as indicated below and on page 863. 

To extract the Soudan dyes shake out the gasoline solution of the fat 
once or. twice with a mixture of 80 parts of 85^^^, phosphoric acid (sp. gr. 
1.70) and 20 parts of concentrated sulphuric acid, but the method is not 
applicable to tolueneazo-^-naphthylamin and other colors sensitive to 
strong acids. The alkali salts of Soudan G and annatto color, being readily 
soluble in water, are most easily removed by shaking out with dilute sodium 
or potassium hydroxide solution. 

Extraction and separation may be carried out together as follows: 
Dilute the melted fat with gasoline and shake out first with 2% (N/2) 
sodium hydroxide solution to remove annatto, Soudan G, etc., and then wash 
several times with 4 to 6 N hydrochloric acid to remove aminoazo deriva- 
tives such as butter yellow and aminoazotoluene. Benzeneazo-j3-naphthyl- 
amin and tolueneazo-/3-naphthylamin are extracted rather slowly, appar- 
ently suffering rearrangement from hydrazo-imin into true azo form before 
going into solution in the acid. Neutralize the acid extract immediately 
to avoid decomposition. Separate the Soudans and similar colors not 
extracted by alkali or acid with phosphoric acid mixture as described above, 
wash once or twice with gasoline, dilute, partially neutralize, and extract 
with ether or gasoline, thus obtaining the color. 

Preservatives and their Detection.— Fresh or unsalted butter 
and renovated butter may contain a preservative. Formerly the one most 
commonly used for this purpose was the so-called " boric mixture " (borax 
and boric acid) well known as a milk preservative. In England the use of 
borax or boric acid is permitted. Sodium benzoate may be used in the 
United States if properly declared, but dairymen seldom take advantage of 
the ruling in the case of butter designed for domestic use. Some brands 
of nut butter contain sodium benzoate. Other preservatives less often used 
in butter are formaldehyde and salicylic and sulphurous acids. 

Boric Acid. — This, if present, is best detected in the aqueous solution 
that settles to the bottom when butter is melted at the temperature of the 
boiling water-bath, the supernatant fat being decanted off. Richmond * 
claims to be able to distinguish free boric acid from borax as follows: 
If on applying turmeric-paper directly to the aqueous liquid the paper turns 
red, the color being especially evident on drying, free boric acid is indicated. 

* Dairy Chemistry, p. 254. 



I 



OILS AND FATS. 561 

As a confirmatory test the reddened turmeric-paper is treated with dilute 
caustic alkali, whereupon it turns a dark olive-green if boric acid is present. 

In the absence of a red color by the above test, or when this color is 
faint, the aqueous solution is acidified slightly with hydrochloric acid 
and the turmeric-paper applied as before. If borax be present to an 
appreciable extent, the red color will now be quite marked, even though 
not appearing before. In other words, testing with turmeric-paper with- 
out acidifying with hydrochloric acid shows, according to Richmond, 
a slight coloration due to the free acid alone, while the more intense color 
formed by first acidifying is due to the combined acid or borax. 

Determination of Boric Acid.— Ten grams of the butter fat are weighed 
in a beaker and transferred with hot water to a separatory funjiel in which 
the fat is extracted with lo to 15 portions of hot water as described on page 
556. The combined aqueous extract is evaporated to dryness in a plati- 
num dish, the residue made alkaline, and ignited at a dull red heat. Boil 
the ash with water, filter, and wash with hot water, keeping the volume 
of the filtrate under 60 cc. Make sure that the solution is perfectly neutral 
to methyl orange by treatment, if necessary, with sulphuric acid and tenth- 
normal alkali, add 30 cc. of glycerin, a few drops of the phenolphthalein 
indicator, make up to 100 cc, and titrate with tenth-normal sodium hydrox- 
ide according to Thompson's method (page 886). 

Butter being practically free from phosphates, the preliminary treat- 
ment for removing phosphoric acid in Thompson's method may be 
omitted. 

Formaldehyde.— The aqueous solution, from which the fat of the 
butter melted at low temperature has been poured off, is added to some 
milk previously found free from formaldehyde, and the test for the latter 
with hydrochloric acid and ferric chloride is tried directly in the milk. 

Salicylic Acid.— Detection.—See method No. 2 for detection in milk, 
page 167. 

Determination of Salicylic Acid. — Method of the Paris Municipal 
LaWa/ory.— Repeatedly exhaust 20 grams of butter in a separatory 
funnel with a solution of sodium bicarbonate, thus obtaining soluble 
sodium salicylate, if salicylic acid be present. Acidulate the aqueous 
extract with dilute sulphuric acid, and extract with ether. Evaporate 
the ether, and to the residue add a little mercuric nitrate, forming a pre- 
cipitate nearly insoluble in water. Filter this off, wash the precipitate 
with water, and decompose into free salicylic acid with dilute sulphuric 
acid. Redissolve in ether, evaporate the solvent as before, and dry the 



562 FOOD INSPECTION AND ANALYSIS. 

residue at a temperature of 80° to 100°. . Extract the residue with petroleum 
ether, dilute the ethereal liquid with an equal volume of 95% alcohol, 
and titrate with tenth-normal alkali, using phenolphthalein as an indicator. 

I cc. of tenth-normal alkali =0.0138 gram salicylic acid. 

Benzoic Acid. — Detection. — Halphen-Rohin Method.^ — Dissolve 0.4 to 
0.5 gram of sodium bicarbonate in 50 cc. of water and 15 cc. of 95% alcohol 
in a separatory funnel, add 25 grams of the melted sample, agitate with a 
rotary motion, allow to stand 6 minutes, and draw off the alkaline liquid 
into a flask. Acidulate the contents of the flask with 7 or 8 drops of concen- 
trated sulphuric or hydrochloric acid, heat nearly to boiling, add a little talc 
or infusorial earth, shake i to 2 minutes, and filter on a folded paper return- 
ing the first portions that run through. Cool the filtrate, shake out with 
40 cc. of ether, wash the ether extract once with a mixture of 20 cc. of water 
and 5 cc. of 95% alcohol, then shake with a mixture of 20 cc. of water, 5 cc. 
of 95% alcohol, and 0.2 to 0.3 gram of sodium bicarbonate. Draw off the 
alkaline solution into a dish and test by the modified Mohler method 
(page 892). 

Sulphurous Acid. — The aqueous liquid, separated from the butter fat, 
is distilled, and the distillate treated with bromine water and barium 
chloride. A precipitate on the addition of the latter reagent indicates the 
presence of sulphurous acid or a sulphite in the butter. 

Glucose in Butter. — Crampton f states that glucose has been found by 
him in butter intended for export to tropical countries, added to pre- 
vent decomposition. In one sample made for export to Guadeloupe 
he found over 10% of glucose. 

For its detection or estimation 10 grams of the sample are weighed 
out and transferred to a separatory funnel with hot water, and shaken 
out with successive portions of hot water. These are combined, and 
the aqueous extract made up to 250 cc. The reducing sugar may be 
determined by Fehling's solution or by polarization, using in the latter 
case alumina cream as a clarifier. While a slight reduction should be 
disregarded, any considerable reduction may be undoubtedly ascribed 
to glucose. 

Butter ''Filled" with Water.— Various preparations have been 
placed on the market to aid in incorporating water with butter. So-called 

* Ann. chim. anal, appl., 13, 1908, p. 431. 
t Jour. Am. Chem. Soc, 20, 1S98, p. 201. 



OILS AND FATS. 563 

" black pepsin " has been used for this purpose. By churning the butter 
with water and a certain amount of the preparation in such a manner 
as to destroy the grain, it is possible to introduce two or three times the 
normal amount of water. 

RENOVATED OR PROCESS BUTTER. 

This product is also variously termed " boiled," " aerated," and 
" sterilized " butter. There are various modifications of the process of 
manufacture, but the object is to melt up and treat rancid butter in such 
a manner that for a time at least it is sweet. The following manner of 
treatment is typical, and shows in the main the necessary steps in carrying 
out the process, though details of manipulation vary in different localities. 

The butter is melted in large tanks surrounded with hot-water jackets 
at a temperature varying from 40° to 45° C. By this means the curd 
and brine settle to the bottom, whence they are drawn off, while the lighter 
particles rise to the top in the form of a froth or scum and are removed 
by skimming. 

The clear butter fat is then, as a rule, removed to other jacketed 
tanks, and, while still in a molten condition, air is blown through it, which 
removes the disagreeable odors. The melted fat is then churned with 
an admixture of milk (more often skimmed) till a perfect emulsion is 
formed, after which it is rapidly chilled by running into ice-cold water, 
with the resnlt that it becomes granular in form. It is then drained 
and " ripened " for some hours, after which it is worked free from excess 
of milk and water, salted, and packed. 

Under some state laws this product, to be legally sold, must conform 
to rules of labeling as strict as those prescribed for oleomargarine. In 
other localities it may be sold with impunity. Not infrequently it is 
sold as choice creamery butter, and sometimes at the same price. 

U. S. Standard Renovated or Process Butter should contain not more 
than 16% of water, and at least 82.5% of butter fat. 

OLEOMARGARINE. 

According to the U. S. revenue laws, artificial butter composed wholly 
or in part of fat other than butter fat must be branded oleomargarine. 
The name butterine, although used in advertising matter, does not have 
the sanction of the government. The product is commonly known in 
England as margarine. As a rule the oleomargarine of commerce is 



564 FOOD INSPECTION AND ANALYSIS. 

composed of refined oleo oil, usually churned up with neutral lard, milk, 
and a small amount of pure butter, the whole being salted and sometimes 
colored to resemble butter. Cottonseed oil and other vegetable oils are 
also used to some extent. 

Oleo Oil is prepared from the fat of beef cattle somewhat as follows.* 
Immediately after the animals are killed the fresh intestinal and caul 
fats are removed and placed in tanks of water at a temperature of about 
80° F. From this water they are transferred to other tanks of cold water 
and chilled until all animal heat is removed. The fat is then cut or 
hashed into small pieces and rendered in jacketed kettles, the temperature 
being kept as low as possible (formerly about 150° F., now less than 1 10° F.) 
to avoid a cooked taste, salt being used to aid the separation. 

The melted fat {premier pis) is drawn off from the connective tissue, 
clarified, and allowed to crystallize for one or more days in graining or 
seeding vats at about 85° F. 

From these vats the semi-solid emulsion of oil and stearin is dipped into 
cloths, which are folded and placed in a press between sheets of metal and 
subjected to powerful pressure. By this means the oil is separated from the 
stearin, and is drawn into casks for export or for manufacture into oleo- 
margarine. Large quantities are annually exported to Holland, where 
oleomargarine is manufactured, and either sold for consumption in that 
country, or re-exported to other countries in Europe. 

The oleo oil thus expressed is a mixture of olein and palmitin. When 
first prepared, it is a clear amber-colored fluid, free from odor or fatty 
taste. It is packed in tierces, and, when opened at ordinary temperature, 
is a light-yellow solid. 

The further process of manufacture of oleomargarine as formerly 
conducted consists in the main of mixing the oleo oil as above obtained 
with varying proportions of neutral lard, milk, and genuine butter, with or 
without added coloring matter, and churning the mixture at a temperature 
above the melting-point of the fats, the neutral lard having previously been 
cured for at least forty-eight hours in salt brine. After the churning, the 
whole mass is cooled by contact with ice water. The chilled mass is 
drained, and afterwards salted, worked, and given much the same treat- 
ment as butter. 

The composition of this type of oleomargarine varies between the 



* Report on Oleomargarine, Its Manufacture and Sale, 19th Ann. Report, Mass. St. Bd. 
of Health, 1887. 



OILS AND FATS. 565 

following limits: Oleo oil, 20 to 25%; neutral lard, 40 to 45%; butter, 
10 to 25%; milk, cream, salt, etc., 5 to 30%. 

Since the manufacture of cottonseed oil has been carried out on a large 
scale this oil has been used in considerable quantity in the United States for 
mixing with animal fats in the production of artificial butter. In certain 
continental countries the addition of a certain amount of sesame oil (in 
Germany 10% of the total fat) is required by law for the purpose of dis- 
tinguishing the product from genuine butter by the Baudouin or some 
similar test. These mixtures respond respectively to the Halphen and 
Baudouin tests, although not appreciably different from animal oleo- 
margarine in their content of soluble and insoluble fatty acids (Reichert- 
Meissl and Polenske numbers) and insoluble fatty acids (Hehner number). 
Like oleomargarine of purely animal origin they are also readily distin- 
guished from butter by their refraction, saponification number, and several 
other constants. 

Vegetable oleomargarine prepared chiefly from cocoanut and palm 
kernel oils is a quite different product, as noted in a subsequent section. 

Coloring of Oleomargarine. — The artificial coloring matters employed 
are the same as in the case of butter, and are. similarly tested for. 

In many states oleomargarine cannot be legally sold when colored 
to resemble butter. Under other state laws coloring matter is allowable. 
The federal law and most state laws prescribe the most rigid rules for 
marking packages containing oleomargarine, with a view to affording 
the utmost protection to the producer of butter against the fraudulent 
substitution therefor. 

Sulphurized Oil. — Cottonseed oil treated with sulphur by a secret 
process has recently been used in oleomargarine. The sulphur is claimed 
to improve the oil, but the fact that a yellow color is imparted is significant. 
Sulphurized oil blackens silver foil or a silver coin when heated at about 
250° C. Quantitative tests are said to furnish no evidence. 

Crampton and Simon's Test for Palm Oil.* — So called " butter 
oils," consisting of cottonseed oil to which has been added 2 to 5% of palm 
oil are used to color oleomargarine. The following tests serve for the 
detection of palm oil. 

Preparation of Sample. — The sample should be kept in a cool, dark 
place until tested, as exposure to air and light, or the presence of water, 
alcohol, ether or similar reagents interfere with the tests. Immediately 

* Jour. Am. Chem. Soc, 27, 1905, p. 270. 



566 FOOD INSPECTION AND ANALYSIS. 

before testing, the sample is filtered as quickly as possible at a temperature 
not exceeding 70° C. 

First Method. — Dissolve 100 cc. of the fat in 300 cc. of petroleum ether, 
and shake out with 50 cc. of 0.5% potassium hydroxide. Draw off the 
watery layer, make distinctly acid with hydrochloric acid, and shake out 
with 10 cc. of colorless C. P. carbon tetrachloride. Separate the carbon 
tetrachloride solution, transfer a portion to a porcelain crucible, add 
2 cc. of a mixture of one part of colorless, crystallize C. P. phenol and 
2 parts of carbon tetrachloride, then 5 drops of hydrobromic acid (sp. gr. 
1. 19), and mix by gentle agitation.* 

The almost immediate development of a bluish-green color is indicative 
of palm oil. 

Second Method. — Shake 10 cc, of the melted and filtered fat with an 
equal volume of colorless C. P. acetic anhydride, add one drop of sulphuric 
acid (sp. gr. 1.53), and shake a few seconds longer.f 

If palm oil be present, the lower layers on settling out will be found 
to be colored blue with a tint of green. The color in this as in the preced- 
ing test is transient. 

Of the edible oils only sesame and mustard oils give a similar color 
reaction. Sesame oil, after repeated extractions with alcohol, will not 
give the blue color, but cottonseed oil containing as little as 1% of palm 
oil still responds to the test. 

Gill X believes this test unreliable because it does not give concordant 
results in the hands of different chemists and being a test for carotin is not 
characteristic of palm oil. 

Adulterants of Oleomargrine. — This product is liable to adultera- 
tion not only by the use of inferior and unwholesome fat, but by the admix- 
ture in some cases of paraffin. § This sophistication is made manifest 
if an appreciable amount of the adulterant has been used, by the high 
melting-point and the low saponification number, as well as by the low 
specific gravity. If a clear saponification is impossible under ordinary 
conditions, paraffin is to be suspected. It may be separated and quanti- 
tatively determined as described on page 527. 



* Halphen uses a similar reagent to detect rosin oil in mineral oil. Jour. Soc. Chem. 
Ind., 21, 1902, p. 1474. 

t The reagents are the same as used in the Liebermann-Storch test for rosin oil. 

X Jour. Ind. Eng. Chem., 9, 191 7, p. 136. 

§ Geissler, Jour. Am. Chem. Soc, 21, 1899, p. 605. 



OILS AND FATS. 567 

Healthfulness of Oleomargarine.— Under the directions of the Mass- 
achusetts Board of Health,* a large number of artificial digestion experi- 
ments were made to show the relative nutritive value of butter and oleo- 
margarine, and at the same time the wholesomeness of oleomargarine 
as a food was carefully investigated. The general conclusions reached 
were that, when comparing the best grades of both products, there is 
little if any difference between butter and oleomargarine on grounds of 
digestibility, while a good oleomargarine is much to be preferred to a 
poor butter from a nutritive standpoint. As to its wholesomeness, a 
large number of experts consulted were unanimous in expressing their 
favorable opinions of oleomargarine as a healthful article of food. 

When sold on its own basis in accordance with the law, it forms an 
excellent cheap substitute for butter. It is only when fraudulently sold 
as butter or in violation of the various state and federal laws, that it comes 
within the province of the health authorities to condemn it, and, unfor- 
tunately, by reason of its close resemblance to the dairy product, the 
temptation to sell it for what it is not is always great. 

Distinction of Oleomargarine from Butter.— The two 
products resemble each other closely in general appearance, consistency* 
and somewhat in flavor. Their distinction involves preliminary organ- 
oleptic test followed by physical and chemical examination. 

Odor and Taste. — It is easy with a little practice to become so accus- 
tomed to the odor and taste of oleomargarine, as to be able to pass judg- 
ment with considerable confidence by these senses alone, whether a sample 
in question is oleomargarine or butter. The distinction is rendered more 
apparent by melting a portion of the sample on the water-bath. If the 
product is butter, either fresh or renovated, the butyric odor of the melted 
fat is very characteristic, while the melted oleomargarine not only is lack- 
ing in the butyric odor (a negative property), but possesses often a " meaty " 
smell peculiar to itself, which, while not unpleasant, is unmistakable. 
The flavor of oleomargarine although not always the same to one experi- 
enced in distinguishing between the two products is very apparent. This 
flavor, though somewhat variable, may he compared to that of cooked meat. 

Qualitative Tests for cottonseed and sesame oils are made by the usual 
color methods and for peanut oil by Renard's or Bellier's method. 

Range of Constants. — By reference to the tables on pages 528 and 529 it 
is evident that the constants of oleo oil and lard are very similar but radically 



19th Ann. Report, Mass. State Board of Health, 1887, p. 248. 



568 



FOOD INSPECTION AND ANALYSIS. 



different from those of butter fat, furthermore that the addition of cotton- 
seed or sesame does not interfere with the ready distinction of oleomargarine 
from butter. For ordinary purposes it is necessary only to determine the 
refraction and the Reichert-Meissl number coupling the determination of 
the latter with that of the Polenske number in case the presence of an 
oil of the cocoanut oil group is suspected. The presence of cottonseed oil 
in the American oleomargarine, readily responding to the Halphen test, 
serves the same purpose as sesame oil compulsorily added to the con- 
tinental product. Other constants and tests are discussed on p. 571. 

The distinction between butter fat, animal fat such as goes to make up 
oleomargarine, and mixture of the two is brought out in the following 
table by Villiers and Collin*: 









Hehner's 


Soluble 


Koettstorfer's 


Volatile 








Number. 


Acids. 


Equivalent. 


Acids. 


Pure butter. ,-- 


88 
88.35 


5 
4-8 


224 
222.6 


26 


Butter, 95%; 


foreign 


fat, 5%--- 


24.7 


" 90% 




" 10%.. . 


88 


70 


4.5 


221.2 


23-4 


" 85% 




" 15%--- 


89 


05 


4.3 


219.8 


22.2 


" 80% 




" 20%... 


89 


40 


4-1 


218.4 


20.9 


" 75% 




" 25%--- 


89 


75 


3-9 


217 


19.6 


" 70% 




" 30%... 


90 


10 


3-6 


215.6 


18-3 


" 65% 




" 35%--- 


90 


45 


3-4 


214.8 


17.1 


" 60% 




" 40%-.- 


90 


80 


3-2 


212.8 


15.8 


" 55% 




" 45%--- 


91 


15 


3 


211. 4 


14-5 


^' 50% 




" 50%... 


91 


50 


2-7 


210 


13.2 


■■• 45% 




" 55%--- 


91 


85 


2-5 


208.6 


12 


'■' 40% 




" 60%... 


92 


20 


2-3 


207.2 


10.7 


" 35% 




" 65%... 


92 


55 


2.1 


205.8 


9-4 


■•' 30% 




" 70%..- 


92 


90 


1.8 


204.4 


8.1 


*' 25% 




" 75%--- 


93 


25 


1.6 


203 


6.9 


*' 20% 




" 80%... 


93 


60 


1.4 


201.6 


5-6 


" 15% 




" 85%... 


93 


95 


1.2 


200.2 


4.3 


" 10% 




" 90%-.- 


94 


30 


0.9 


198.8 


3 


". 5% 




" 95%- -• 


94 


65 


0.7 


197.4 


1.8 


Foreign fat. . 






0=; 


0-5 


196 


o.< 




yo 




•J 



Butyro-refractoineter Readings. — The instrument, as its name implies, 
was primarily intended by Zeiss for the examination of butter, and, while 
its use has been extended for work with other fats and oils, its construc- 
tion is such as to show particularly a distinction between butter and 
oleomargarine by the appearance of the critical line of the fat. This 
mode of differentiation is due to the peculiar construction of the double 
prism, which shows differences of dispersive power by different appear.' 
ances of the critical line. The prisms are so constructed that the critical 



* Les Substances Alimentaires, p. 731. 



EDIBLE OILS AND FATS. 569 

line of pure butter is colorless, while margarine and artificial butter, which 
have greater dispersive powers than natural butter, show 'a blue-colored 
critical line. But anomalies in the color, both with pure butter and mix- 
tures, are more or less observable, which render it impossible to draw a 
sharp line between adulterated and genuine butter. The appearance of 
a blue fringe may, however, be a useful factor in cases of suspected adultera- 
tion. 

The following figures for index of refraction and butyro-refractometer 
readings at 25° C. are by WoUny.* The oleomargarine was undoubtedly 
free from cocoanut and palm kernel oils : 

Natural butter i. 4590-1. 4620; 49.5-54.0 scale divisions 

Oleomargarine i. 4650-1. 4700; 58.6-66.4 scale divisions 

Mixtures (artificial butter) i. 4620-1. 4690; 54.0-64.8 scale divisions 

Limit of Scale Reading for Pure Butter. — Whenever in the refracto- 
metric examination of butter at a temperature of 25° C. higher values 
than 54.0 are found for the critical line, these samples will, according 
to Wollny, by chemical analysis always be found to be adulterated; but 
with all samples in which the value for the position of the critical line 
does not reach 54.0 chemical analysis may be dispensed with, and the 
samples may be pronounced to be pure butter. Wollny suggests, as a 
means of removing all chances of adulterated butter escaping detection, 
that the above limit be placed still lower, and that all samples exhibiting 
values exceeding 52.5 (at a temperature of 25° C.) be set aside for chemi- 
cal analysis. 

In calculating the position of the critical line for other temperatures 
than 25° C. allow per 1° C. variation of temperature a mean value of 
0.55 scale division. t The table on page 570, which has been compiled in 
this manner, shows the values corresponding to various temperatures, 
each value being the upper limit of scale divisions admissible in pure 
butter. 

If, therefore, at any temperature between 45° and 25° values be found 
for the critical line which are less than the values corresponding to the 
same temperature according to the table, the sample of butter may safely 



* Schlussbericht iiber die Butteruntersuchungsfrage, Milchwirthschaftlicher Verein, Kor- 
respondenzblatt, No. 39, 1891, p. 15. 

t With natural butter this number is, as a rule, somewhat less (0.52), with oleomargarine 
a little greater (0.56). 



570 



FOOD INSPECTION AND ANALYSIS. 



Temper- 
ature. 


Scale 
Division. 


Temper- 
ature. 


Scale 1 
Division. 


Temper- 
ature. 


Scale 
Division. 


Temper- 
ature. 


Scale 
Division. 


45° 


41-5 


40° 


44.2 


35° 


47.0 


30° 


49.8 


44° 


42.0 


39° 


44.8 


34° 


47-5 


29° 


50-3 


43° 


42.6 


38° 


45-3 


33° 


48.1 


28° 


50.8 


42° 


43- 1 


37° 


45-9 


32° 


48.6 


27° 


514 


41° 


43-7 


36° 


46.4 


31° 


49.2 


26° 


519 


40° 


44.2 


35° 


47.0 


30° 


49.8 


25° 


52.5 



be pronounced to be natural, i.e., unadulterated butter. If the reading 
shows higher numbers for the critical line, the sample should be reserved for 
chemical analysis. 

Note. — Dr. Eichel of Metz has suggested that instead of comparing 
the scale divisions at the same temperature, the position of the critical 



i 



line may be determined at the moment when the butter 
begins to set. In this case he gives fifty-four as the highest 
admissible number for the critical line of pure butter. 

No sharp distinction is apparent between pure and 
renovated butter on the refractometer. 

Special Thermometer for the Butyro-refractometer. — 
Instead of employing the ordinary thermometer, as shown 
in Fig. 36, a special thermometer (Fig. loi) has been de- 
vised for work both with butter and with lard. This in- 
strument has two scales, arranged side by side, one for 
butter and one for lard, each of which indicates at once 
the highest allowable reading for the pure fat, correspond- 
ing to the temperature at which the observation is made, 
which, however, need not be noted. 

If the scale reading of the instrument, as observed 
through the telescope, differs materially from the reading 
of the special thermometer, the fat under examination is 
undoubtedly adulterated, or, in the case of butter, a 
higher reading indicates oleomargarine. The special ther- 
FiG.ioi.— Special j^Qj^etej- thus indicates the highest permissible number for 

Butyro-refrac- 

tometer Ther- P^re butter. 

mometer for The Relchert-Meissl Number (see page 497) is by far the 
Butter and j^Qst important single determination in establishing proof 
of the character of the sample, whether butter or oleo- 
margarine, for evidence in court, and in such cases this determination 
is indispensable. The result is conclusive, excepting in those instances 



OILS AND FATS. 571 

(rare in the United States) where the admixture of animal oleomargarine 
is small or the foreign fat is cocoanut or palm kernel oil skillfully pro- 
portioned to the butter (see table, page 500). 

It is difficult to fix a minimum figure below which, in doubtful cases, 
a sample may be pronounced impure by reason of admixture with foreign 
fat. In general, however, a Reichert-Meissl number under 20 would be 
almost sure to show adulteration, though instances are on record where 
butter of known purity has fallen even lower than this. It is in fact rare 
that pure butter has a number under 24. 

Stebbins * gives the maximum, minimum, and average of the Reichert 
number obtained by him on 317 samples of unadulterated butter, some of 
which were of low grade, as follows: Maximum, 18.2; Minimum, 11.2; 
Average, 14.7. These figures should be multiplied by 2 for comparison 
with Reichert-Meissl numbers. 

As a rule little difference is apparent between pure and " renovated " 
samples as regards their Reichert-Meissl numbers. 

Vieth has shown that the Reichert number of butter is generally a 
trifle lower after it becomes rancid. 

The Polenske Number is valuable in detecting cocoanut or palm 
kernel oil in butter as is obvious from a study of the figures given in the table 
on page 500. Other methods which have been proposed for the purpose are 
the Jensen-Kirschner method (page 501), the Ave-Lallement method,! the 
Robin method, J the Shrewsbury-Knapp method, § and the Hanus method. 1 1 

The Halphen and Baudouin tests serve to detect cottonseed and sesame 
oils respectively. 

Distinction of Butter, Process Butter, and Oleomar- 
garine. — With the increased occurrence in the market of the commercial 
product known as " process " butter, especially in localities where its sale 
is restricted or regulated by law, it becomes incumbent on the analyst to 
distinguish it from the other products which it resembles. 

As a rule, the tests, chiefly physical, that are applied on the edible prod- 
uct as a wJwle (i.e., without separation of the curd, salt, etc.), such as the 
foam test, the milk test, the microscopical examination, and the appear- 
ance of the melted sample, distinguish broadly between pure fresh butter 

* Jour. Amer. Chem. Soc, 21, 1899, P- 939- 

t Zeits. Unters. Nahr. Genussm., 14, 1907, p. 318. 

X Compt. rend., 143, 1906, p. 512; 8th Int. Cong. App. Chem., 18, 1912, p. 305. 

§ Analyst 35, 1910, p. 385; 37, 1912, p. 3. 

II Zeits. Unter-Nahr. Genussm, 13, 1907, p. 18. 



572 FOOD INSPECTION AND ANALYSIS. 

on the one hand, and oleomargarine on the other. In other words, 
although there are those skilled in making the above tests who claim to 
be and doubtless are able to note distinguishing features between oleo- 
margarine and process butter, yet these two products respond alike, 
though perhaps in varying degrees, to these tests, and are classed together 
as distinguished from pure butter. 

On the other hand, such tests as depend upon the refractometer, 
the Reichert-Meissl number, and, indeed, all the chemical constants 
which are applied to the separated fat, freed from other substances, will 
serve to distinguish between oleomargarine and butter, whether " pro- 
cess " butter or otherwise, since the "processing" or " renovating " of 
butter does not change the character of its fat sufficiently to materially 
alter these constants. 

It is best, therefore, for purposes of routine preliminary separation 
to submit all samples to the " foam " test and to examine them by the 
butyro-refractometer. These tests alone, which are very quickly and readily 
applied, will rarely fail to separate into the three classes, butter, pro- 
cess butter, and oleomargarine, the products under examination, after which 
such confirmatory tests as are desired are made on adulterated samples. 

The Foam Test, also known as the "boiling" or "spoon" test.* 
This, though originally intended as a household test, is in reality one of 
the very best laboratory methods of separating pure butter samples from 
renovated butter and oleomargarine. A small lump of the sample (from 
3 to 5 grams) is heated in a large spoon over a Bunsen flame, turned 
very low, stirring constantly during the heating. Genuine butter, under 
these conditions, will boil quietly, but with the production of consider- 
able froth or foam, which will often swell up over the sides of the spoon, 
when, just after boiling, the latter is raised from the flame. Renovated 
butter or oleomargarine, under this treatment, will bump and sputter 
noisily like hot grease containing water, but will not foam.f Another 
point of difference is that on removing the spoon from the flame and 
observing the character of the curdy particles, in the case of genuine 
butter these particles of curd will be very small and finely di\dded in the 
melted fat, being indeed hardly perceptible, while with oleomargarine 
and renovated butter, the curd will gather in somewhat large masses or 
lumps. 

* U. S. Dept. Agric, Farmers' Bui. 131. 

t A very slight foam is sometimes observable with occasional renovated samples, but 
nothing like the abundant amount produced by the genuine product. 



OILS AND FATS. 573 

The test may be carried out in a test-tube if desired. 

The Waterhouse or Milk Test.*— This test is based on the assump- 
tion that butter fat, which is in itself exclusively the product of milk, 
will mingle intimately with the milk when added thereto in a melted 
condition and cooled therein, whereas oleomargarine, being foreign to 
milk fat, will, under like conditions, refuse to diffuse itself naturally 
in milk as a medium. 

About 50 cc. of well-mixed sweet milk are heated nearly to boiling 
in a beaker, and from 5 to 10 grams of the fat sample are added. The 
mixture is then stirred, preferably with a small wooden stick, until the 
fat is melted. The beaker is then placed in a dish of ice-cold water, and 
the stirring continued till the fat reaches the solidifying-point, at which 
period, if the sample is oleomargarine, the fat can readily be collected 
by the stirrer into one lump or clot, but, if butter, it cannot be so collected, 
but remains in a granulated condition, distributed through the milk in 
small particles. It is not necessary to keep up the stirring through the 
entire term of cooling, but to begin stirring before the fat starts to solidify, 
which should require from 10 to 15 minutes after the mixture is placed in 
cold water. 

This test, if carefully carried out, shows a marked distinction between 
butter, whether pure or renovated, and oleomargarine. Under certain 
conditions, as when the cooling is too rapid, samples of renovated butter 
fat will sometimes show a slight tendency to clot together as in the case 
of oleomargarine, but to no such extent as the latter. 

The authors' experience with this test has shown it to be very reliable, 
not only in identifying oleomargarine from butter, but in nearly every 
case renovated butter can be distinguished from genuine. As a rule, 
genuine butter fat, even after cooling to the solidifying-point, shows the 
greatest tendency to emulsionize with the milk when stirred, without 
adhering to the wooden rod, and is slow to come to the surface when the 
stirring is stopped. Renovated butter fat, when stirred in the cold milk, 
almost instantly gathers in a film on the surface of the milk when the 
stirring is stopped, without emulsionizing. It does not clot together like 
oleomargarine, but it tends to adhere to the wooden rod. 

Patrick f recommends the use of skimmed or partially skimmed 
milk, and heats to the boiling-point after the fat has been introduced 
into the hot milk. 

* Parsons, Jour. Amer. Chem. Soc, 23, 1901, p. 200. 
t Farmer's Bulletin, No. 131. 



574 FOOD INSPECTION AND ANALYSIS. 

Examination of the Curd. — The curd of genuine butter is made up 
largely of such of the milk proteins as are insoluble in water, and hence 
pass into the cream when separated. These proteins form a gelatinous 
mass in the butter, readily clotting together when the fat is melted. On 
the other hand, the curd of process butter, which is, as it were, artificially 
derived from the entire or skim milk used in its manufacture (in order 
to replace the natural curd which has been removed in the " purifying " 
process), differs from the proteins of cream in that it is granular and 
flaky, consisting chiefly of coagulated casein. Hence the distinction 
noted as to the appearance of the curd in the foam test. 

For the same reason, if beakers containing pure and renovated butter 
are melted on the water-bath, the curd of the pure sample will settle at 
once, or in a very few minutes, to the bottom after melting, leaving a 
comparatively clear supernatant fat. The renovated sample will nearly 
always fail to settle out clear, even after standing on the water-bath for 
half an hour or more, but will still be cloudy throughout the mass, due 
to particles of non-cohesive, floating curd. 

In the case of oleomargarine, the curd of which is composed partly 
of pure butter curd (from cream proteins) and partly of the proteins of 
the milk with which it is churned, the cloudiness of the fat on melting 
depends on the relative proportion of milk proteins, and in general is not 
especially characteristic. 

Identification of the Source of the Curd.* Half fill a small beaker 
with the sample and melt on the water-bath. Decant as much as possible 
of the fat and pour the rest, consisting largely of the water, salt, and 
curd, upon a wet filter. Acidify the filtrate, which contains the salt 
and soluble proteins, with acetic acid and boil. If the sample is pure 
butter, only a slight milkiness is found, indicating absence of albumins, 
whereas, in the case of process butter, a white, flocculent albuminous 
precipitate is produced. 

Apply to the filtrate also Liebermann's test for albumin; i.e., add 
strong hydrochloric acid. If a violet coloration is produced, the sample 
is presumably " process " butter. 

Microscopical Examination of Butter. — Considerable information may 
in general be gained by an examination of the sample under ordinary 
light and with a rather low power, say from 120 to 150 diameters. For 
examination in this way a bit of the sample on the edge of a knife blade 

*Hess and Doolittle, Jour. Am. Chem. Soc, 22, 1900, p. 151. 



OILS AND FATS. 575 

is placed on the glass slide, and simply pressed lightly into a thin film 
by the cover-glass. A very characteristic difference between genuine 
and renovated butter is at once seen in the relative opacity of the fields. 
The fat film, in the case of the fresh, pure butter, is much more transparent 
than that of the renovated. Again, the curd is so finely divided through- 
out the mass of genuine butter fat that the field is much more even than 
that of the renovated, w^herein often large and opaque patches of curd 
are frequently distributed throughout the field. 

When a renovated butter sample, mounted as above, is viewed hy 
reflected lights for which purpose the microscope mirror is turned so as 
not to transmit light through the instrument, one sees a very dark and 
scarcely perceptible field; but the opaque patches of curd above referred 
to are strikingly apparent as white masses against a dark background. 

With Polarized Light. — It has already been stated that the micro- 
scope is useful in showing whether or not a fat. has been melted, the 
crystalline structure of the fat once melted and afterward cooled being 
rendered apparent, especially when viewed by polarized light. This 
fact has long been known and put to practical use in the identification 
microscopically of butter and oleomargarine.* 

When viewed by polarized light between crossed Nicols under a low 
magnification, pure butter not previously melted should show no crystal- 
line structure, being uniformly bright throughout, and, if the selenite 
plate be used, should present an even colored field, entirely devoid of 
fat crystals. On the other hand, with process butter or oleomargarine, 
both of which have been melted and subsequently cooled the crystalline 
structure should be marked, showing with polarized light a more or less 
mottled appearance, and a play of colors with the selenite. 

Various conditions enter in to affect the reliability of the polarized light 
test. It is nearly always possible in cold weather to observe these dis- 
tinctions in practice, as above described, in a sharp and striking manner. 
Figs. 269, 270, and 271, PI. XXXVIII, show typical fields of the three 
products with crossed Nicols and selenite plate. The appearance of pure 
butter is perfectly blank, while oleomargarine presents a much more 
mottled appearance than renovated butter. Such well-defined points 
of variation as are shown in PI. XXXVIII are not always to be seen in 
practice, even in the hands of an expert. Pure butter sometimes exhibits 
a somewhat mottled field, due to a slight crystallization at some period 
of its history. In the summer-time, for instance, when butter melts so 
* Hummell, ibid., 22, p. 327; Crampton, loc. cit., supra, p. 703. 



576 FOOD INSPECTION AND ANALYSIS. 

easily at ordinary temperatures, these distinctions between pure and 
adulterated samples as shown by polarized light are by no means as satis- 
factory as in the winter. 

Great care should be taken on this account, on the part of the col- 
lector of samples as well as the analyst, to keep the sample from melting 
under ordinary conditions before it is examined. 

Hess and Doolittle's Method of Examining the Curd.*— A convenient 
portion of the sample of suspected butter is melted in a beaker, as much 
of the fat as possible is decanted off, and the remaining curd, washed 
free from fat with ether, is poured out on a glass plate, and dried. A 
sample of pure butter is treated in like manner by way of comparison. 
When examined under a very low magnification of from 3 to 6 diameters, 
the curd from the pure sample will be seen to be non-granular and amor- 
phous in appearance, while, in the case of renovated butter, the curd 
will appear very coarse grained and mottled. 

Zega's Test for Oleomargarine. f — A portion of the filtered-fat is 
poured into a test-tube and kept for two minutes in a boiling water-bath. 
I cc. of this fat is then measured with a hot pipette into a 50-cc. tube con- 
taining 20 cc. of a mixture of 6 parts ether, 4 parts alcohol, and i part 
glacial acetic acid. The tube is stoppered, shaken well, and cooled in 
water at 15° to 18° C. In the case of pure butter fat, the solution remains 
clear for some time, a slight deposit being apparent only after standing 
an hour or more. With oleomargarine, a deposit is evident in a very 
short time, and in ten minutes a heavy precipitate comes down. With 
10% of oleomargarine in butter, a separation occurs in about fifteen 
minutes. When a few solid particles have separated out, they are with- 
drawn and examined under the microscope. With genuine butter, long 
narrow rods appear, sometimes pointed at the ends, often bent, and grouped 
as a rule centrally in star-shaped bundles. Oleomargarine presents an 
appearance of bundles of fine needles, closely packed to form masses 
frequently resembling sheaves and dumb bells in shape. 

VEGETABLE OLEOMARGARINE (NUT BUTTER). 

Cocoanut oil and palm kernel oil are especially adapted to the 
preparation of vegetable butter. Following are the constants of the fat 
of two vegetable butters " Sanella " and " Tomor." J 

* Jour. Am. Chem. Soc, 22, 1900, p. 151. 

t Chem. Ztg., 1899, 23, p. 312. 

J Pharm. Zentrh., 48, p. 16; 49, p. 490. 



OILS AND FATS. 



577 





Refraction 
25° C. 


Reichert-Meissl 
No. 


Polenske 
No. 


Saponification 
No. 


Sanella, Summer 

Sanella, Winter 


38.5 
42.0 


7-9 
6.5 
8.0 


15.6 

II. 2 

15-8 


247.0 
238.8 


Tomor 


250.1 









The above figures indicate that the chief constituent of both prepara- 
tions is cocoanut oil; they also contain sesame oil. Both products were 
colored, salted, and churned with a liquid preparation of almonds and egg 
yolk. 

Nut butters are coming into favor in the United States. Much of the 
cocoanut oil brought into the country or made from imported copra since the 
beginning of the great war is utilized in these products. The products are 
sold in bricks, packed in attractive cartons. Although notably different 
from animal oleomargarine they are labeled " oleomargarine " to comply 
with the federal law, in addition, however, the package usually bears a 
special name suggesting cocoanut oil. 

Some of the brands contain benzoate of soda as a preservative, which 
is declared on the label; others are free from chemical preservatives. All 
are placed on the market uncolored, but at the time of sale a capsule con- 
taining a liquid color is given the purchaser who from directions on the 
label can color the product if he sees fit. 



LARD. 

Nature and Composition. — Lard is the fat of hogs, separated by heat 
from the scraps or containing tissues. The choicest or highest grade of 
lard is known as leaf lard, and is derived from the fat which surrounds 
the kidneys. A comparatively small part of the lard of commerce is, 
however, strictly speaking, pure leaf lard. Most of it is derived from 
the whole fat of the animal by rendering, by the aid of steam under pres- 
sure, either in open kettle or in closed tanks, the former being used more 
often for rendering lard on a small scale, and the latter being the most 
common commercial method. 

Next to the leaf, the fat from the hog's back is considered the best 
in quality, after which is graded, in the order named, the fat from the 
head, the region of the heart, and the small intestines, the last two grades 
constituting what is commonly known as " trimmings." 

Good lard is white and granular, having the consistency of salve. It 
has an agreeable, characteristic odor and taste. 



578 



FOOD INSPECTION AND ANALYSIS. 



The leaf or kidney fat furnishes also the source of the so-called neutral 
lard, already mentioned as an ingredient of oleomargarine. The leaf, 
being first chilled and finely ground, is placed in the kettle and ren- 
dered at a temperature of from 40° to 50° C, at which heat only a portion 
of the lard separates. This portion is, while melted, washed with water 
containing salt or dilute acid, and fofms the neutral lard, a product almost 
entirely free from odor. The remainder of the lead is then transferred 
to the closed tank and subjected for some hours to steam under pressure 
at a temperature of 230° to 290° F., the resulting lard being graded as pure 
leaf lard. 

The composition of the mixed fatty acids of lard is thus calculated 
by Twitchell : • 

Linoleic acid 10 .06% 

Oleic acid 49 . 39% 

Solid acids (by difference), stearic and palmitic 48.55% 

The solid triglycerides consist in part of a-palmito distearin which has 
a different crystalline form from the /3-palmito distearin of tallow, thus 
explaining the results obtained in the Belfield test, 

Dennstedt and Voigtlander * gives the following constants for American 
lards made from fat from different parts of the animal : 



Fat from 



Head 

Back. 

Leaf. 

Foot. 
Ham. 



Ham (German) . . 



specific 
Gravity 

at 100° C. 

(Water at 
15° C. =1.) 



0.8637 
0.8629 
0.8631 
O.8611 
0.8621 
0.8616 
0.8637 
0.8615 
0.8700 
0.8589 
0.8641 
0.8615 
0.8628 



Iodine 
Value. 



66.2 
66.6 
65.0 
61.5 
65.0 

65.1 
62.2 
590 
63.0 
68.8 
68.4 
66.6 
68.3 



0.8597 



550 



Maumene 

Number at 

40° C. 



33 
32 
34 

37 
35 
38 



30 
38 



30 



Melting-point, Bense- 
mann's Method. 



Temp. C. 

of Incipient 

Fusion. 



24 

24 

24 

28.5 

28.5 

31-5 
26 

29 
28.5 

24 
26 
26 
26 



Melted to 
a Clear 
Drop. 



32 



46 

45 

44 

44-5 

40 

45 

44 

44-5 



Refractive 
Index. 



Butyro- 

refractom- 

eter at 

40° C. 



46 



52.6 

52.5 
52.0 

524 
51.8 
51-9 
514 
50.2 
52.0 
44.8 
Si-9 
Si-9 
530 

49.2 



* Lewkowitsch, Chem. Tech. and Anal, of Oils, Fats, and Waxes, sth Ed., 2, 1914, p. 701. 



OILS AND FATS. 



579 



Effects of Feeding Hogs on Oil Cakes. — Fulmer,* Emmett and 
Grindley f and other investigators have found that feeding cottonseed 
meal to hogs causes the lard from these hogs to give a color with the 
Halphen test, but Tolman | Farnsteiner, § and Polenske 1 1 have shown 
that the lard does not contain phytosterol when examined by Bomer's 
phytosterol acetate method. 

Lard from hogs fed on sesame cake has been shown to respond to the 
Baudouin test, but not to the phytosterol acetate test. 

Lard from " Oily Hogs" is quite different from the ordinary products. 
Richardson and Farey ^ have analyzed one sample of back fat, three of leaf 
lard, and two of ham fat with the following average results: 





Melting-point. 


Refract- 
ive 
Index, 
40°. 


Saponi- 
fication 

No. 


Iodine 

No. 


Free 
Fatty 
Acids 

as 
Oleic. 


Insoluble Fatty Acids. 




Open 
Capil- 
lary, 
Lower 

Limit. 


Closed 
Capil- 
lary, 
Upper 
Limit. 


Titer 
Test. 


Liquid 
Acids. 


Iodine 
No. 


Back fat 

Leaf lard 

Ham fat 


-1-5° 
-0.5 
— 1.2 


+ 12.0° 
+ 20.0 
+ IS-5 


1.4620 
1.4620 
I . 4630 


189.0 
191. 1 
189.7 


93-9 
93-9 
94.0 


0. 16 
0. 19 
0.18 


21.2° 

22.9 

20.6 


89.4 
87.8 
86. s 


104.5 
107.9 
109.0 



U. S. Standards. — Standard Lard and Standard Leaf Lard are lard and 
leaf lard respectively, free from rancidity, containing not more than 1% 
of substances other than fatty acids, not fat, necessarily incorporated 
therewith in the process of rendering, and standard leaf lard has an iodine 
number not greater than 60. 

U. S. P. Standards. — Melting-point, 36-42° C; saponification value, 
195-203; iodine value, 46-70; 10 grams of sample dissolved in 30 mils 
of chloroform mixed with 10 mils of neutral alcohol and i drop of 
phenolphthalein solution require not more than 2 mils N/io alkali for 
neutralization. Qualitative and microscopic tests are also given. 

Lard Oil. — This oil is obtained by subjecting lard contained in woolen 
bags to hydraulic pressure in the cold. The lard oil (chiefly olein) thus 
expressed constitutes nearly 60% of the whole, and the residue is known as 
lard stearin. 

* Jour. Amer. Chem. Soc, 26, 1904, p. 837. 

t Ibid., 27, 1905, p. 263. 

tibid., 27, 1905, p. 589. 

§ Zeits. Unters. Nahr. Genussm., 11, 1906, p. i. 

II Arb. kaisl. Gesundheitsamt, 22, 105, p. 568. 

If Jour. Amer. Chem. Soc, 30, 1908, p. 1191. 



580 



FOOD INSPECTION AND ANALYSIS. 



Lard oil is a thin fluid, pale yellow in color, and with varying specific 
gravity, due to varying conditions of pressure and temperature. It has 
a pleasant, though somewhat bland, taste, and is used to some extent as 
an edible oil. It is used in France as an adulterant of olive oil, and with 
the Maumene, elaidin, and nitric acid tests, it behaves much like olive oil. 

Adulterants of lard oil are cottonseed and corn oils. 

Compound Lard. — The article sold under this name is a mixture 
consisting usually of beef or lard stearin and cottonseed oil. Sometimes 
no lard whatever is present. Lard stearin is the residue left in the cloths 
after the lard oil has been removed by pressure (page 579). Beef stearin 
is, similarly, the residue from which oleo oil has been expressed (page 564). 
The cottonseed oil used is highly refined, and finally decolorized by mixing 
with fuller's earth and filtering. 

Lard Substitutes differ from compound lard in that they contain no 
hog fat and are sold under distinct names in competition with lard. They 
consist of various mixtures of cottonseed oil with stearin (usually beef) or 
of hydrogenated cottonseed oil. Wesson states that cocoanut oil, although 
used in large amount in vegetable butter in the United States, is not 
suitable for lard substitutes, as it causes the mixture to froth on heating. 
When hydrogenated oils are used traces of nickel may be present, although 
now less often than formerly. 

Examples of lard substitutes are Fairbanks' " Cottolene," Southern 
Cotton Oil Company's " Snowdrift " and " Scoco," Proctor & Gamble's 
" Crisco," Armour's " Vegetole," Swift's " Jewel " and " Crescent," and 
Wilson's " Advance." 





Iodine No. 


Melting- 


Titer 
Test. 


Free Fatty 
Acids. 


Color. 


Flavor. 




point. 


Yellow. 


Red. 


I 


98.2 


42.9 


35-7 


0.13 


32 


3-2 


Good 


II 


97-4 


50 


2 


36.2 


0.14 


35 


4.8 


Poor 


III 


95-1 


50 


8 


37-2 


0. 19 


32 


3-2 


Poor 


IV 


97-3 


47 


5 


35-9 


0. 10 


26 


2.8 


Poor 


V 


95-6 


41 


6 


36.9 


0. II 


17 


1-7 


Good 


VI 


95 I 


48 


8 


37-3 


0. 14 


35 


6.2 


Poor 


VII 


98.0 


46 


8 


35-9 


0.13 


27 


2.7 


Good 


VIII 


89.0 


50 


4 




0.14 


35 


4-9 


Fair 


IX 


96. 1 


42 


2 


36.4 


0. II 


35 


3-6 


Good 


X 


93-7 


43 





36.7 


0. 12 


20 


2.0 


Fair 


XI 


85.2 


53 


I 


35-6 


0.18 


35 


4-3 


Poor 


XII 


78.1 


33 


7 


34-4 


0.09 


22 


2.2 


Good 



OILS AND FATS. 



581 



The table on p. 580, kindly furnished by DrrDavid Wesson, gives the 
results of examination of the leading brands of compound lard and lard 
substitutes on the American market. The color values are of the melted 
fat in terms of yellow and red as read in 5|-inch cells of the Lovibond 
tintometer. 

Adulteration of Lard. — " Compound lard," although properly branded 
by the manufacturer, may be sold for pure lard by the retailer. This 
substitution and the addition of beef tallow to lard are the common forms 
of adulteration practiced in the United States. Other oils that may be 
looked for are cocoanut, palm kernel, corn peanut, and sesame. Formerly 
water was incorporated with the fat to such an extent as to materially 
cheapen it, but this sophistication is now rare. 

Analyses of Pure and Compound Lard. — Leach gives analyses together 
with conclusions drawn therefrom as follows : 

ANALYSES OF SAMPLES ILLUSTRATLNTG TYPES OF LARD, LARD SUBSTI- 
TUTES, AND MIXTURES. 



Nitric Acid Test. 



Crystallization. 





Butyro-re 


frac- 






tometer. 












Bechi Reac- 


3 






s 


tion. 


?io! 


hi 


C u 
cd 


2 




fthn 


fl 


5 6 S 


G 






0) 

<u 
Pi 


c 0=3 





None 


42-5 


49-7 


+ 0.1 


58.1 




42 


50 


+ 0.2 


59-9 




41-5 


50.1 


+ 0.0 


58.7 




43 


50 


+ 0.6 


63-7 




41-3 


51 


-f 0.8 


64.6 




42 


50-5 


+ 0.7 


64.8 




42 


49-7 


— C.I 


56.4 




SO 


41.2 


-3-8 


37-3 


Deep color 


42 


5«-7 


+ 8.9 


108 


<( << 


43 


50-5 


+ 1-3 


69 -S 


None 


43 


48.5 


-0.7 


55-2 


Deep color 


43-5 


51 


+ 1.1 


71.4 


«' << 


43-7 


50.1 


+ 1-3 


66.7 




43-5 


49-1 


+ 0.3 


54-7 



Conclusion. 



A 
B 
C 
D 
E 
F 
G 
H 
I 

J 
K 
L 

M 

N 



Slight color. 
Red 

Slight color 



Very slight color 
Deep-brown red 

Red 



Lard stearin 



Very slight color 

Deep brown 

Red 



Beef stearin 
Few small 

bunches 
Lard stearin 

Lard and 

beef stearin 
Lard stearin 



Lard and 
beef stearin 



Lard 



Leaf lard 
Beef tallow 
Cottonseed oil 

Lard and cotton- 
seed oil 

Lard and beef 
tallow 

Lard and cotton- 
seed oil 
Ditto 

Lard, beef tallow, 
and cottonseed 
oil 



Notes on the Above Table.— It will in general be noted that adultera- 
tion of lard with cottonseed oil alone is indicated by an abnormally high 
refractometer number, while the presence of tallow will result in an 



582 FOOD INSPECTION AND ANALYSIS. 

abnormally low refraction. But both adulterants may be present and 
a normal refraction result. In such a case the positive detection of one 
of them, such as the cottonseed oil by the Bechi or Halphen test, will 
indirectly show the presence of the other (tallow), and this indu-ect proof 
will be confirmed by crystallization. 

Samples A, B and C give reactions corresponding to normal, pure 
lard. D, E, and F show somewhat high refractometer and iodine num- 
bers, but give no direct reaction for cottonseed oil by the Bechi test. 
G, although showing low iodine and refractometer numbers, gives no 
evidence of the presence of tallow by crystallization. In fact, the crys- 
tals from this sample proved under all circumstances to be most clearly 
typical of pure lard, broad and flat plates with obliquely cut ends. 

This sample was, in fact, pure leaf lard. It is generally true that a 
stiff, strictly pure leaf lard, which both by its consistency and by its low 
iodine and refractometer numbers might suggest the presence of beef fat, 
shows on crystallization much more definitely characteristic lard stearin 
than does a whole-hog lard, whose iodine and refractometer numbers are 
more nearly the normal standard. 

In distinction from such leaf lard, a sample which may have a similar 
consistency and iodine and refractometer numbers, but which is composed 
of a whole-hog lard of a comparatively high iodine number, together with 
beef fat, gives unmistakable proof of its adulteration by its crystallization, 

METHODS OF ANALYSIS. 

Detection of Beef Stearin or Tallow. — Beljield-Gladdmg Microscopic 
Method."^ — Dissolve 2 to 2.5 grams of the melted sample with the aid 
of heat in 7.5 cc. of ether-absolute alcohol (i : 2), cool in ice water until a 
copious precipitate forms, filter, and wash once or twice with the ether- 
alcohol mixture. Dry at room temperature, transfer to a test-tube, and 
dissolve in 15 cc. of ether. Loosely stopper the test-tube with cotton, 
place in a vessel containing sufficient water to insure a uniform tempera- 
ture, and allow to stand for some hours until abundant crystals are formed. 
Examine under the microscope in ether as a medium or if desired in 
alcohol or oil. 

If the crystals are, however, in a pulverulent condition, a drop of 
alcohol can be used as a mountant, or oil, as preferred. Mounted under 
a cover-glass they are examined under various powers of the microscope. 

* Jour. Amer. Chem. Soc, 18, 1896, p. 189. 



OILS AND FATS 583 

Figs. 272 and 273, PL XXXIX, show the typical appearance of pure 
lard stearin from a leaf lard of known purity, and Figs. 276, 277, and 
278, PI. XL, illustrate beef stearin. These figures show distinctive crystal- 
lization of each form under the best conditions. The lard stearin crystals 
when thus obtained are flat rhomboidal plates cut off obliquely at one 
end, and are grouped irregularly, as if thrown carelessly together. The 
beef stearin crystals, on the other hand, are cylindrical rods or needles, 
often curved, with sharp ends, and are arranged as shown in fan-shaped 
clusters. Conditions of crystallization are frequently such as not to 
show the sharp distinctions noted above. Both forms of crystals are at 
times apt to gather in clusters that at first sight appear somewhat similar, 
and are often misleading as to their true character. It is found almost 
invariably that the beef stearin crystals gather in clusters, radiating from 
a common center or point, often with a peculiar twisted appearance, 
breaking up into little fans. Lard crystals, it is true, do not always lie 
fiat in irregular groups as shown in Fig. 272, but, as in Fig. 274, form 
clusters that, unless studied carefully, might at first sight be considered 
as identical with the fan shapes of the beef stearin already described. 
It will be seen, however, that if the best possible conditions are attained, 
the crystals of lard, instead of radiating from a point, are arranged more 
like feathers or alternate leaves on a branch, each crystal being given forth 
from another close at hand. Moreover, the lard crystals are themselves 
straight and not curved, the apparent curve in the appearance of the 
clusters being, on careful examination, especially under high power, 
seen to be chiefly due to several of these straight crystals arranged at 
angles to each other. 

Even when the highest powers of the microscope are applied to the 
beef stearin crystals, they will always appear as cylindrical, sharp-pointed 
rods, some straight, others curved; while with the lard crystals they 
should be capable of showing the thin, fiat, oblique-ended structure when 
examined with higher powers, even when they are arranged in the feathery 
clusters, the apparently pointed ends of some of the crystals being due 
to the fact that the plates are viewed edgewise. This is apparent in 
Fig. 275, in which the crystals are magnified to 480 diameters. 

Leys-Emery Melting-point Method.^ — Place 5 grams of the warm 
filtered fat in a glass-stoppered 25-cc. cylinder, 150 to 175 mm. high and 18 



*Leys, jour, pharm. chim., [6], 26, 1907, p. 289; Emery, U. S. Dept. Agric. Bur. Anim. 
Ind. Circ, 132. 



584 FOOD INSPECTION AND ANALYSIS. 

mm. inside diameter, add 25 cc. of warm ether, stopper, shake vigorously 
until the fat is dissolved, and allow to stand 18 hours at 20 to 25° C. Decant 
off the liquid, wash with two portions of 5 cc. of ether by decantation, 
and use a third portion for transferring to the filter. Wash with cold 
ether, using a total of 10 to 15 cc. with the aid of slight suction at the end. 
Spread out the crystals on filter-paper and when dry mix well and determine 
the melting-point in a capillary tube i mm. in diameter, filling so as to 
form a column 9 mm. high and compacting firmly by tapping. The point 
when the substance appears perfectly clear and transparent is taken as the 
true melting-point. 

Thirty samples of leaf lard gave melting-points from 63.6 to 64.1. Sam- 
ples below 63.4 are regarded as suspicious and below 63 as adulterated. 

Detection of Cottonseed Oil. — This is best accomplished by the Halphen 
test and the determination of the refraction, specific gravity, and the iodine 
number. See tables pages 528 and 529. 

Detection of Cocoanut and Palm Kernel Oils. — The Reichert-Meissl 
and Polenske numbers furnish the best evidence. The iodine and saponi- 
fication numbers also are useful in diagnosis. See table page 528, also 
figures given after descriptions of the methods. 

Detection of Com Oil. — In the absence of cottonseed oil and sesame 
oils, as shown by qualitative tests, corn oil is indicated by an abnormally 
high refraction and iodine number, the maximum for cottonseed oil being 
usually lower than the minimum for corn oil. In case these constants are 
not decisive apply the Bomer phytosterol acetate test. According to 
McPherson and Ruth,* the crystals thus obtained from lard melt at 1 13°, 
those from corn oil at 127 to 128°. 

Detection of Sesame Oil. — The Baudouin and Villivecchia-Fabris 
tests are decisive for appreciable amounts. The iodine number is also 
useful. 

Detection of Peanut Oil. — The test for arachidic and lignoceric acids 
should be applied. 

Detection of Nickel in Hydrogenated Lard Substitutes. — Prall-Kerr 
Method. '\ — Warm 10 grams of the fat with 10 cc. of hydrochloric acid 
(sp. gr. 1. 1 2) in a test-tube on a water-bath for 2 or 3 hours with repeated 
shaking and filter on a wet paper into a porcelain dish. Evaporate off 



*Ohio Dairy and Food Com. Ann. Rep. 1906. 

t Zeits. Unters. Nahr. Genussm., 24, 1912, p. 109; Jour. Ind. Eng. Chem., 6, 1914, 
p. 207. 



OILS AND FATS. 585 

most of the acid on a water-bath, add 2 to 3 cc. of concentrated nitric 
acid and continue the evaporation to dryness to destroy organic matter. 
Dissolve the residue in a few cc. of water and add a few drops of each 
1% solution of dimethylglyoxime in alcohol, and dilute ammonia water. 
If nickel is present a red color appears which for quantitative estimation 
may be compared with the color developed in a standard solution of a 
nickel salt. 

Iron and copper are said to interfere although the color of ferric 
hydroxide is not the same as that formed in the presence of nickel. 

Detection of Paraffin. — See page 527. 



'h 



CHAPTER XrV. 
SUGAR AND SACCHARINE PRODUCTS. 

Nature and Classification "of Sugars.— Of all classes of food mate- 
rials the sugars from their great solubility are the most readily available, 
and on this account are very valuable as nutrients. As in the natural 
processes of digestion the starches and more difficultly digestible of the 
carbohydrates are converted into sugar and thus rendered assimilable, 
so by processes quite analogous to those that take place in the alimentary 
tract, the chemist converts these same carbohydrates into sugar as an 
end-point for purposes of definite determination. 

The sugars are characterized by their sweet taste, their ready solu- 
bility in water, their power to rotate the plane of polarized light, and 
theu: insolubility in ether and absolute alcohol. 

The sugars occurring commonly in food naturally divide themselves 
into two groups: First, the Hexoses (CtiHi206) including dextrose, levulose, 
and galactose; second, the Disaccharides (C12H22O11) especially sucrose, 
maltose, and lactose. Other sugars occurring less frequently or in smaller 
amount as well as a classification of all the food carbohydrates are given 
on pages 35-38. 

The members of both groups are intimately related. Thus by the 
ordinary process of so-called inversion sucrose, or cane sugar, belonging to 
the disaccharides, is converted by the action of heat and dilute acid into 
two sugars, dextrose and levulose, belonging to the hexoses, in accord- 
ance with the following reaction: 

Ci2H220ii-hH20 = C6H,o06+CnHi206. 

Cane sugar Dextrose Levulose 

The same equation expresses also the result that takes place when 
lactose, or milk sugar, is heated with dilute acids, breaking up into dextrose 
and galactose. 

586 



SUGAR AND SACCHARINE PRODUCTS 



587 



Occurrence. — Sugars occur in roots, grasses, stems of plants, trunks 
of trees, leaves, and fruits, usually in the form of cane sugar, or sucrose, 
and of invert sugar (dextrose and levulose) mixed in varying propor- 
tions. 

The following table from Buignet * shows the kind and amount of 
sugars occurring in some of the common fruits : 



Apricots 

Pineapples 

English cherries. . 

Lemons 

Figs 

Strawberries 

Raspberries 

Gooseberries 

Oranges 

Peaches (green). . 
Pears (Madeleine) 
Apples 

Prunes 

Grapes (hothouse) 
' ' green 



Cane Sugar. 



6.04 

11-33 
.00 

.41 
.00 

^■33 

2.01 

.00 

4.22 

.92 

-36 

5.28 

2.19 

5-24 
.00 
.00 



Reducing 
Sugar. 



2-74 

1.98 

10.00 

1.06 

11-55 
4.98 

5-22 
6.40 

4-36 
1.07 
8.42 
8.72 

5-45 

2.43 

17.26 

1.60 



Acid. 



1.864 

•547 

.661 

4.706 

•057 

-550 

1.380 

1-574 

-448 

3.900 

-115 
1. 148 

■(>23 
1.288 

•345 
2.485 



CANE SUGAR, OR SUCROSE. 

Nature and Occurrence. — ^This, the most common of all the sugars, 
is nearly always understood by the unqualified term of sugar. It crys- 
tallizes in monoclinic prisms. Its specific gravity is 1.595. Its melting- 
point is about 160° C. Its specific rotary power .[a:]^, in solutions having 
a concentration of from 10 to 20 grams in 100 cc. is, according to Tollens, 
66.48°. Sucrose is extremely soluble in water, which, when cold, will 
hold in solution twice its weight of the sugar. 

Cane sugar is ordinarily derived from four sources — the sugar beet, 
the sugar cane, the maple tree, and the sorghum plant. The first two 
sources supply the principal output of commercial cane sugar, about 
half the sugar on the world's market being furnished, by the sugar beet 
and the other half by the sugar cane. It should be understood that the 
product sucrose, or cane sugar, is chemically the same whether derived 
from either of the above sources and thoroughly refined. 

U. S. Standard Sugar is white sugar containing at least 99.5% of 
sucrose. 



Ann. Chim. Phys., 59, 233. 



588 



FOOD INSPECTION AND ANALYSIS. 



The Sugar Cane {Saccharum officinarum) is cultivated principally in 
Louisiana and other southern states, in Cuba and the West Indies, and 
in the Hawaiian Islands. Its growth and cultivation form an industry 
in nearly all tropical countries. 

Allen * has compiled the following table showing the composition 
of the juice of the sugar cane from different localities: 



Locality and Kind 
of Cane. 


Water. 


Sugar. 


Woody- 
Fiber. 


Salts. 


Authority. 


Martinique 


72.1 
72.0 
77.0 

65-9 
69.0 

76-73 
76.08 


18.0 
17.8 
12.0 
17.7 
20.0 

13-39 
14.28 


9-9 

9-8 

II. 

16.4 

10. 

9.07 

8.87 


0.4 
I.O 

•39 

•35 


Peligot 
Dupuy 
Casaseca 


Guadaloupe 

Havana. ........... 


Cuba 


Casaseca 


Mauritius ......... 


leery 

Avequin 

Avequin 


Ribbon cane 

Tahiti 





The composition of raw cane sugar ash according to Monier is as 
follows : 

RAW CANE SUGAR ASH. 

Carbonate of calcium 49 .00 

" " potassium 16.50 

Sodium and potassium sulphate 16.00 

Sodium chloride 9 .00 

Silica and alumina 9 . 50 



100.00 



Manufacture of Cane Sugar. — ^The process of manufacturing raw 
sugar from sugar cane is briefly as follows: The juice is first extracted 
from the canes by crushing in roll mills and is freed from nitrogenous 
bodies, organic acids, etc., by the process of defecation, which consists 
in heating to coagulate the albumin, and nearly neutralizing with milk 
of lime, the impurities being removed as a scum. The juice is then 
subjected to evaporation and crystallization, the raw, or muscovado sugar, 
which contains from 87 to 91 per cent of sucrose, being separated from 
the molasses, which is the mother liquor, by draining or by centrifugal. 

Some of the best grade of muscovado, or raw sugar, is used as ' ' brown 
sugar" without further refining, and much of the molasses is used as a 
table syrup and for cooking, while the lower grades of molasses are used 
in the manufacture of rum. 

* Com. Org. Anal., 4 Ed., Vol. I, p. 359. 



t 



SUGAR AND SACCHARINE PRODUCTS. 



589 



The following table from Thorpe * shows the average comp osition 
of raw and refined sugar: 



Cane 
Sugar. 



Glucose'. 



Water. 



Organic 
Matter. 



Ash. 



RAW SUGAR. 



Good centrifugal . 
Poor centrifugal . . 
Good muscovado. 
Poor muscovado . 

Molasses sugar 

Jaggary sugar 

Manilla sugar 

Beet sugar, ist 

Beet sugar, 2d . . . 



REFINED SUGAR. 

Granulated sugar 

White coffee sugar 

Yellow X C sugar 

Yellow sugar 

Barrel sugar 



96-5 
92.0 
91.0 
82.0 
85-0 

75-0 
87.0 

95-0 
91.0 



99.8 
91.0 
87.0 
82.0 
40.0 



0-75 
2.50 
2.25 
7.00 
3.00 
11.00 

5-50 
0.00 
0.25 



0.20 
2.40 
4-50 
7-50 
25.00 



1.50 
3.00 
5.00 
6.00 
5.00 
8.00 
4.00 
2.00 
3.00 



0.00 

5-5° 

6.00 

6.00 

20.00 



0.85 

I-7S 
1. 10 

3-5° 
5.00 
4.00 
2.25 
1-75 
3-25 



0.00 
0.80 
1.50 
2.50 
10.00 



0.40 

0-75 
0.65 
1.50 
2.00 
2.00 
1.25 

1-25 
2.50 

0.00 
0.30 
1. 00 
2.00 
5.00 



1 The term "glucose" includes sugars which reduce Fehling's solution, but are not necessarily 
optically active. 

The following minimum and maximum figures are taken from analyses 
made by Babington f of twenty-two samples of brown sugar and thirty- 
one samples of molasses. 



BROWN SUGAR. 

Direct polarization 84 

Invert " -27 

Sucrose by Clerget 83 . 5 

Reducing sugar 3 

Moisture 3.5 

Ash 0.8 

MOLASSES. 

Direct polarization — 30 

Invert " — 10 

Sucrose by Clerget 32 

Reducing sugar 13 

Moisture 29 

Ash 0.5 

* Outlines of Industrial Chem., p. 383. 
t Can. Inl. Rev. Dept. Bui. 25. 



to 



to 



87 
29 

91-5 
6 

6 
3-0 



50 
— 21 

52 
24 
32 
4 



590 



FOOD INSPECTION AND ANALYSIS. 



The Sugar Beet {Beta vulgaris) is grown chiefly in France and Ger- 
many, and to a lesser extent in Holland and England. The successful 
growth of the sugar beet in the United States is confined mainly to Cali- 
fornia, Colorado, Utah, and Nebraska, and the entire output of beet sugar 
in this country is comparatively small. 

According to R. Hoffmann, sugar beets have about the following 
composition, three types being selected — first, those poor in sugar; second, 
those having a medium sugar content, and third, those rich in sugar: 



COMPOSITION OF THE SUGAR BEET. 



First Type. 



Second Type. 



Third Type. 



Water 

Sugar 

Nitrogenous compounds 

Non-nitrogenous compounds 

Soluble 

Insoluble (cellulose) 

Ash 



89. 20 
4.00 

1. 00 

4-13 

1. 01 
0.66 



83.20 
9.42 
1.64 

3-34 
1.50 
0.90 



75.20 

15.00 

2.20 

4.23 
2.07 
1.30 



The following is the mean composition of ten samples of California 
sugar beet : * 

Per cent juice extracted 61 .38 

Specific gravity i .062 to i .075 

Per cent of reducing sugar 0.91 

Per cent of sucrose 14-38 

Total solids calculated 16.58 

Total solids weighed 1 7 . 20 

Per cent of ash 0-994 

The composition of beet sugar ash according to Monier is as follows: 

RAW BEET SUGAR ASH. 

Carbonates of potassium and sodium 82 . 20 

Carbonate of calcium 6. 70 

Potassium and sodium sulphate and sodium chloride. ... 11 .10 

100.00 

Manufacture of Beet Sugar. — In making raw sugar from sugar beets 
the latter are first washed and sliced by machinery and the juice extracted 
* U. S. Dept. of Agric, Div. of Chem., Bui. 27, p. 302. 



SUGAR AND SACCHARINE PRODUCTS. 591 

by diffusion or digestion with warm water. The juice is then clarified 
or defecated in much the same manner as that from the sugar cane, after 
which it is usually bleached with sulphur dioxide. 

The subsequent evaporation and crystallization are carried out usu- 
ally in vacuum pans, and the sugar separated out by centrifugals. 

Beet sugar molasses is unfit for food, due to the presence of nitroge- 
nous bodies, which give it a very unpleasant taste and smell. 

Process of Refining. — In refining raw sugar, a syrup is made, which 
is subjected to centrifuging and further defecation, using lime, clay, 
liquid blood, calcium acid phosphate, and other substances as clarifiers. 
The syrup is then filtered, first through cloth bags and then through 
bone char, after which it is evaporated and allowed to crystallize, the 
resulting granulated sugar being separated, as in the case of raw sugar, 
by centrifugal machines. 

Granulated Sugar of commerce is without doubt the purest food product 
on the market, being generally 99.8% sucrose. It is usually treated with 
an extremely weak solution of ultramarine to counteract the natural 
yellow color. 

The syrup from which the granulated sugar is separated forms the 
"golden," or "drip," syrup used on the table. Its typical composition 
•s as follows: Sucrose, 40%; reducing sugars, 25%; water, 20%; organic 
natter, 10%; ash, 5%. 

The dry sugars, whether white or brown, are rarely subjected to 
adulteration. 

Maple Sap. — The sap of the maple tree, Acer saccharinum, or Acer 
barbatum, furnishes a sugar considerably prized for its peculiar flavor. 
The maple sugar industry is largely confined to the northeastern states 
and to Canada, and the maple sugar season is generally limited to six 
weeks or two months in the spring. 

The following are minimum and maximum figures from the analyses 
of five samples of maple sap made in Massachusetts : 

Specific gravity i .007 to i .015 

Sucrose 0.769 " 2.777 

Reducing sugar " 0.012 

The ash of maple sap varies from 0.04 to o. i per cent. Albuminoids 
are present in amount varying from 0.008 to 0.03 per cent. 

Maple Sugar and Syrup are made by, simply boiling down the sap 
to the proper consistency, usually in open pans, and removing the scum 



592 



FOOD INSPECTION AND ANALYSIS. 



with great care, since this contains nitrogenous matters that would cause 
fermentation in the finished product. Pure cane sugar is never com- 
mercially produced from the maple sap, since the refining process would 
deprive it of the flavor which gives to maple sugar the chief value. 

McGill gives the following as the average analyses of six samples 
of maple syrup of known purity: 





Saccharim- 
eter Invert. 


Cane Sugar 
by Clerget. 


By Copper. 


Ash. 


Water. 




Saccharim- 
eter Direct. 


Reducing 
Sugar. 


Cane Sugar. 


Solids. 


+ 62.2 


— 21.2 


62.4 


.42 


63-36 


-53 


35-7° 


64.30 



The variation in the composition of pure maple products is shown 
by the following table compiled by A. H. Bryan * from analyses published 
by Hortvetjt Jones,{ and Winton§, and some sixty analyses made at 
the sugar laboratory of the Bureau of Chemistry, U. S, Department of 
Agriculture. 



Maple Sugar. 



Mini- 
mum. 



Maxi- 
mum. 



Average. 



Maple Syrup. 



Mini- 
mum. 



Maxi- 
mum. 



Average. 



Water per cent 

Direct polarization " 

Invert sugar " 

Lead number 

Total ash per cent 

Soluble ash " 

Insoluble ash " 

Alkalinity of soluble ash 

Alkalinity of insoluble ash 

Ratio of insoluble to soluble ash 

Iodine reaction 

Polarization at 87° after inversion °V. 

Malic acid value 



3-05 
72.6 
1. 16 

1.83 
0.64 

0-33 
0.20 
0.40 

0-55 
0.50 



II. o 

■87.4 
8-37 
2.48 
1.32 
0.67 
0.87 

0-95 
1.72 
2.20 



- 2.0 
0.65 



+ 2.0 
1.67 



2.23 
0.91 
0.46 
0.46 
0.63 
0.94 
1. 00 
none 



Not m 

51-0 
0-34 
1. 19 
0.46 
0.21 
0.14 
0.26 
0.31 
0.60 



ore tha 
62.2 
9.17 
2.03 
1. 01 
0.63 
0.56 
C.68 
0.94 



0.41 



+ 2.0 
1.76 



n 32.00 



1-49 
0.60 
0.38 
0.23 
0.50 

0-S4 
1.70 
none 

0.78 



In the table which follows appear the maximum, minimum, and average 
results obtained in the four most extensive investigations of genuine maple 



* U. S. Dept. Agric, Bur. of Chem., Circular No. 40, p. 10. 
t Jour. Am. Chem. Soc, 26, 1904, p. 1523. 
I Vt. Agric. Exp. Sta. Rep., 1904, p. 446; 1905, p. 315. 
§ Jour. Am. Chem. Soc, 28, 1906, p. 1204. 



SUGAR AND SACCHARINE PRODUCTS. 



593 



syrup which have yet been undertaken * as compiled by Snell and Scott. 
The electrical conductivity and volumetric lead values are not included. 
(See pages 659 and 661.) 



SUMMARY OF ANALYSES OF MAPLE SYRUP BY DIFFERENT ANALYSTS 
CALCULATED TO THE DRY SUBSTANCE. 



Maximum: 

Bryan 

Jones 

McGill 

Snell and Scott. 
Minimum: 

Bryan 

Jones 

McGill 

Snell and Scott. 
Average : 

Bryan 

Jones 

McGill 

Snell and Scott. 



No. 
of 
Sam- 
ples. 




Ash. 




Alkalinity of 
Ash. 




Lead No 




Total. 


Sol- 
uble. 


Insol- 
uble. 


Sol- 
uble. 


Insol- 
uble. 


Cana- 
dian. 


Win- 

lon 

(25 g. 

Syrup) 


Win- 
ton 
(25 g. 
Dry 
Mat- 
ter) 


481 

48 

456 

126 

481 

48 

456 

126 

481 

48 

456 

126 


1.68 
1.32 
1.38* 
1.58 

0.68 
0.77 
0.69* 
0.61 

I.oo 
0.92 

0.89* 
0.88 


I 23 

0.72 

0.79* 

0.77 

0-35 
0.45 
0.33* 
0.30 

0.63 
58 
0.56* 
48 


1. 01 

0.78 

075* 
0.92 

0.23 
0.25 
12* 
0. 16 

0.37 
0.34 
0.33* 
0.40 


122 
102 


208 
145 




4.41 




6.56 
7.50 


2 38t 
1.76 


4.09 


103 

41 
46 


201 

41 

55 


1-37 
1-74 


lost 
2.70 


1.41 


51 

75 
79 


48 

97 
83 


2.83 
3 48 


i.75t 


2.30 


68 


116 



Malic 
Acid 
Value. 



1.60 
I II 
I i6t 
I 46 

o 29 
0.65 
o 3ot 
0.38 

0.84 
o 82 
o 77t 
0-7S 



* IIS samples. t 47 samples. J 452 samples. 

A summary of 363 analyses of authenticated samples of maple sugar 
by A. H. Bryan f with the collaboration of Straughn, Church, Given, 
and Sherwood appears in the table which follows. The analyses were 
made on syrup prepared as described on page 656, but the results are cal- 
culated to the dry basis. 



* Bryan, U. S. Dept. of Agric. Bur. of Chem. Bui. 134, 1910; Jones, Vt. Agr. Exp. Sta. 
Rep., 1904-5, p. 315; McGill, Lab. Int. Rev. Dept. Ottawa Bui. 228, 1911; Snell and, Scott, 
Jour. Ind. Eng. Chem., 6, 1914, p. 216. 

t U. S. Dept. of Agric. Bui. 466, 1917. 



594 



FOOD INSPECTION AND ANALYSIS. 





Number 
of 
Anal- 
yses. 


Sucrose. 


Invert 
Sugar. 


Total 
Ash. 


Soluble 
Ash. 


Insol- 
uble 
Ash. _ 


Undeter- 
mined 


Winton 
Lead 

No.* 


Malic 
Acid 
Value. 


United States: 
Maximum . . 


283 


98.62 
57-04 
91.89 

96-59 
58-92 
86.46 


37-3° 
0.09 

5-46 

35 26 
0.88 
8.76 


1.66 
0.76 
0-95 

1.70 
0. 76 
1.06 


I. 14 

0.37 
0.62 

0.89 
0.31 
0.61 


0.81 

0. 21 
0-33 

1. 00 
0. 24 
0-45 


5-84 
0.00 
1.70 

8.18 
0.02 
3-70 


4-95 
1-85 
2.68 

4.14 
1.86 
3-04 


1.72 

0-51 
0.91 

1-51 
0.62 


Minimum . . 




Average. . . . 




Canada : 

Ma.ximum. . 


80 


Minimum . . 




Average. . . . 




I 03 







* Determinations on 308 samples by Ross modification: Max. S-90, min. 2.20, av. 3.50. 

Partial ash analyses of maple products and brown sugar have been 
made by Jones * with the following maxima and minima results : 









100 Parts of Ash Contain 




Ratio of 








Number 
















of 
Analysis. 






























CaO. 


K2O. 


SO3. 


CaO to K2O 


CaO to SO3 


KoQ to SO3 














X 100. 


X 100. 


Xioo. 


Maple syrup: 


Min. . . . 


6 


18.03 


30.00 


0.68 


ISO 


3-4 


1-9 




Max. .. 




23.98 


38.98 


2.30 


181 


12.7 


7-2 


Maple sugar: 


Min. . . . 


4 


21.03 


18.26 


I-51 


57 


5-2 


5-1 




Max 




31-74 


32-95 


2.42 


153 


10.4 


9-4 


Brown rugar: 


Min. . . . 


4* 


4-17 


30.72 


4-58 


257 


27 


II 




Max 




21.62 


55-40 


17-78 


949 


157 


58 



* Including one analysis by Hortvet. 

U. S. standards for Maple Products. — Maple Sugar is the solid 
product resulting from the evaporation of maple sap, and contains in the 
water-free substance not less than 0.65% of maple sugar ash. 

Maple syrup is syrup made by the evaporation of maple sap or by the 
solution of maple concrete, and contains not more than 32% of water 
and not less than 0.45% of maple syrup ash. 

Adulteration of Maple Sugar and Syrup. — The chief adulterants of 
maple sugar are brown, or molasses sugar, and white, or refined sugar, 
the latter being (5ften used in mixture with burnt or inferior maple stock, 
which itself would be abnormally dark in color and of a rank taste. 
Maple syrup is commonly adulterated with a syrup made from refined 
cane sugar, less often with golden or drip syrup, or molasses. Gluco.se, 
which formerly was a common adulterant, is now seldom employed. 

* Loc. cit., 1905, p. 331. 



SUGAR AND SACCHARINE PRODUCTS/ ^ 595 

Refined Sugar or refined sugar syrup added to maple products, while 
not greatly affecting the polarization, diminishes the percentage of total 
ash and the lead number, as well as the malic acid value and ash constants. 

According to analyses by Jones and Hortvet, brown sugar of various 
grades contains from 0.59 to 4.33% of total ash, some of the grades with 
low ash content, or syrups made from them, not being distinguishable 
from maple sugar or maple syrup respectively by this determination alone; 
the ratio of insoluble to soluble ash, however, is commonly higher in 
brown sugar than in maple products. It is frequently possible to identify 
brown, or molasses sugar, especially when it forms the larger portion 
of the alleged maple sugar or syrup, by the physical sense of taste. When 
the perfectly characteristic taste of brown, or molasses sugar, or of "drip 
syrup," so far predominates over the maple flavor as to be unmistakable, 
especially in cases where the maple flavor is entirely lacking, one need 
have little hesitation in condemning the product. 

Glucose in maple products is detected by polarization both before and 
after inversion. A reading of the inverted solution much in excess of 
3° Ventzke at 87° C. furnishes evidence of the presence of this adul- 
terant. 

Sorghum {Andropogon sorghum, variety saccharatus) has for many 
years been grown quite extensively in the southern and western states, 
and used as a source of syrup which is highly prized because of its distinc- 
tive flavor. 

Much experimental work was carried out by Collier * in the early 
eighties and prior thereto with the belief that the sorghum plant would 
become an important source of commercial crystallized sugar, but experi- 
ments were at length abandoned. 

The composition of the juice of the sorghum plant is shown by the 
following results of analyses of eleven varieties made by Hardin.| 

Total solids 15-97 to 18.71 

Specific gravity 1.0656 to 1.0775 

Solids not sugar 5.02 to 10.63 

Cane sugar 2.81 to 8.01 

Reducing sugars 3.87 to 7.55 

Some varieties of sorghum juice have been known to contain 15 or 
even 17% of sucrose. 

* See numerous government reports. 

t U. S. Dept. Agric. Div. Chem. Bui. 37, p. 75. 



596 FOOD INSPECTION AND ANALYSIS. 

In making syrup from sorghum, the ripe canes are crushed, the juice 
is heated with milk of Hme, and the scum removed. The juice is then 
concentrated usually in open pans to the required consistency. 

The following analysis of sorghum syrup is by Jordan and Chesley.* 

Total solids 74-63 

Sucrose 40 .00 

Reducing sugars 28.42 

Gums and extractives 4 -03 

Ash 2 .82 

Acidity as tartaric o - 79 

GRAPE SUGAR, OR DEXTROSE. 

Dextrose (C6H12O6+H2O), designated (/-glucose by Fisher and 
known in its commercial form as starch sugar, occurs in honey with 
levulose, and in fruits with both levulose and cane sugar. It is produced 
by the action of dilute acids or of certain ferments on starch, dextrin, 
or cane sugar. Grapes contain about 15% of dextrose. Anhydrous 
dextrose is soluble in 1.2 parts of cold water. It is soluble in alcohol, but 
less so than cane sugar. It is much less sweet than cane sugar. 

The specific rotary power of dextrose is 

[a]o = 52.3, [«];•= 58. 

A normal solution of dextrose on the Soleil-Ventzke scale polarizes at 
78.6°. For the commercial preparation of dextrose see p. 598. 

U. S. Standards for Various Sugars. — Standard 70 sugar, or brewers^ 
sugar, is hydrous starch sugar containing not less than 70% of dextrose, 
and not more than 0.8% of ash. 

Standard 80 sugar, climax, or acme sugar, is hydrous starch sugar 
containing not less than 80% of dextrose., and not more than 1.5% of ash. 

Standard anhydrous starch sugar is anhydrous starch sugar contain- 
ing not less than 95% of dextrose without water of crystallization, and 
not more than 0.8% of ash. 

The ash of these standard products consists almost entirely of chlorides 
and sulphates of lime and soda. 

LEVULOSE. 

Levulose, also known as (/-fructose and /-(^-fructose, occurs in foods 
as the product of inversion of cane sugar. It is prepared by the action 

* Jour. Ind. Eng. Chem., 9, 1917, p. 256. 



SUGAR AND SACCHARINE PRODUCTS. 597 

of dilute acids on inulin. Normally it is in the form of a syrup, but 
with extreme care pure anhydrous levulose can be obtained. Diabetene 
is a commercial form of dry levulose. Levulose is formed with dextrose 
in the inversion of cane sugar (page 586), and with dextrose occurs in honey 
and in many fruits. The specific rotary power of levulose varies with 
the temperature. At 15° C. [«]z)= -98.8°, decreasing by 0.6385° for 
each degree increase in temperature. Its left-handed reading on the 
Ventzke sugar scale at 15° C. is equivalent to 148.6°. Levulose is sweeter 
than dextrose. Its reducing power on Fehling's solution is assumed 
to be the same as that of dextrose. 

MALT SUGAR, OR MALTOSE. 

Maltose (C,,li,.0,,+ B.,0) is of little importance from the standpoint 
of the food analyst, excepting as an ingredient of commercial glucose, 
and as being the sugar produced by the action of ptyaline, the ferment 
of the saliva on the starch of food in the ordinary process of digestion. 
When gelatinized starch is subjected to treatment with malt extract at 
55° to 60° C, it is converted into dextrin and maltose as follows: 
ioCi'>H.oOio + 8H20 = 2Ci2H2oOio + 8Ci2H220ii. 

"starch Dextrin Maltose 

In its commercial preparation maltose is separated from dextrin by 
crystallization in alcohol. By the action of weak acids and heat both 
dextrin and maltose are further converted into dextrose. 

Maltose usually crystallizes in minute needles, and its molecule of 
water is expelled at 110° C. It is somewhat less soluble in water than 
dextrose. It is shghtly soluble in alcohol, though less than sucrose. So- 
lutions of maltose possess the property of birotation; i.e., when freshly 
prepared they do not at once assume their true optical activity. The 
rotation of a freshly prepared solution of maUose increases on standing, 
requiring several hours to reach its maximum. The specific rotary 
power, according to O 'Sullivan, of anhydrous maltose is [a]z) = i39-2. 
[«],.= 154.5. For hydrated maltose [a]o would thus be 132.2. 

A normal solution of maltose hydrate on the Soleil -Ventzke scale should 
polarize at 198.8°. 

DEXTRIN. COMMERCIAL GLUCOSE. 

DEXTRIN, (CeHioOs)^, possesses more the nature of a gum than of a 
sugar, and is sometimes called British gum. It is said to occur naturally 
in the sap of various plants, but this is not definitely assured. 



598 FOOD INSPECTION AND ANALYSIS. 

It undoubtedly occurs in beer and in bread crust, and is one of the 
constituents of commercial glucose. Like starch, it is convertible by 
hydrolysis with acid into dextrose. By treatment of starch with malt 
extract or diastase, starch is converted into dextrin and maltose, these 
two bodies being separated, in the commercial preparations of dextrin, 
by repeated treatment with alcohol. 

Dextrin is an uncrystallized, colorless, tasteless body, capable of 
being pulverized. It is readily soluble in water, slightly soluble in dilute 
alcohol, but insoluble in alcohol of 60% or stronger. It is not colored 
by iodine, and exercises no reducing action on alkaline copper solution. 
Its specific rotary power is [cx]]j = 2oo, [a]j= 222. 

Amylodextrin, erythrodextrin and achroodextrin are intermediate 
products formed in the transformation of starch into dextrose. Amylo- 
dextrin is colored purple and erythrodextrin red by iodine solution, while 
achroodextrin produces no coloration. It is probable that some of these 
dextrins are not simple substances. 

Commercial Glucose, otherwise known as mixing syrup, crystal syrup, 
and starch, or corn syrup, is a heavy, mildly sweet, colorless, semi-fluid 
substance, having a gravity of 40° to 45° Baume. It is largely used as 
an adulterant of maple syrup, molasses, honey, drip syrup, and jellies 
and jams, and as an ingredient of confectionery. 

In France and Germany it is made from potato starch, but in the United 
States mainly from corn starch. The conversion is effected by boiling 
with dilute sulphuric or hydrochloric acid, after which the acid is neutral- 
ized with marble dust, or sodium carbonate respectively, the juice is 
filtered through bone black, and finally concentrated by evaporation, 
the degree of conversion and of concentration depending on whether 
the liquid glucose or the solid dextrose is wanted for the final product. 
The end product obtained by complete conversion is the dry commercial 
grape sugar, or dextrose, which is purified by repeated crystallization. 

Commercial glucose is a mixture of dextrin, maltose, and dextrose 
cf the following varying composition: 

Dextriri 29.8% to 45-3% 

Maltose 4-6% " i9-3% 

Dextrose 34-3% "36-5% 

Ash 0.32%" 0-52% 

Water 14-2% "17.2% 



SUGAR AND SACCHARINE PRODUCTS. 599 

Calcium sulphate is usually found in the ash if sulphuric acid was used 
for conversion. 

Solid commercial grape sugar, or dextrose, has the following coni' 
position : 

Dextrin o% Q-iVo 

Maltose o% i .8% 

Dextrose 72% 99-4% 

Ash 0.3% 0.75% 

Water 0.6% 17.5% 

U. S. Standard glucose, mixing glucose, or confectioners' glucose, is color- 
less glucose, varying in density between 41° and 45° Baume, at a tempera- 
ture of 100° F. (37.7° C). It conforms in density, within these limits, to 
the degree Baume it is claimed to show, and for a density of 41° Baume 
contains not more than 21% of water, and for a density of 45° not more 
than 14%. It contains on a basis of 41° Baume not more than 1% of 
ash, consisting chiefly of chlorides and sulphates of lime and soda. 

Healthfulness of Glucose. — The analyst alleging commercial glucose 
as an adulterant is frequently asked in court as to its healthfulness, so 
that the following conclusions of a committee appointed some years ago 
by the National Academy of Sciences to ascertain among other things 
whether there is any danger attending the use of this product in food are 
in point: "First, that the manufacture of sugar from starch is a long- 
established industry, scientifically valuable and commercially important; 
second, that the processes which it employs at the present time are unob- 
jectionable in their character and leave the product uncontaminated; 
third, that the starch sugar thus made and sent into commerce is of excep- 
tional purity and uniformity of composition and contains no injurious 
substances; and fourth, that though having at best only about two- 
thirds the sweetening power of cane sugar, yet starch sugar is in no way 
inferior in healthfulness, there being no evidence before the committee 
that maize starch sugar, either in its normal condition or fermented, has 
any deleterious effect upon the system, even when taken in large quan- 
tities." 

MILK SUGAR, OR LACTOSE. 

Lactose (C12H22O11+H2O) is prepared commercially from skim- 
milk by coagulating with rennet and digesting the whey with chalk and 
aluminum hydroxide. The insoluble matter is filtered out, and the 
filtrate is concentrated in vacuo to a syrup, which, on standing, yields 



600 FOOD INSPECTION AND ANALYSIS. 

crystals of lactose. The product is purified by repeated crystalliza- 
tion. 

Lactose ordinarily crystallizes in rhombic, hemihedral crystals. Its 
specific gravity is 1.525. Its water of crystallization is lost by drying at 
130° C. It is soluble in 6 parts of cold water, and in 2^ or less of boiling 
water. It is insoluble in absolute alcohol and ether. It has a very slightly 
sweet taste. 

The specific rotary power of milk sugar, after remaining in solution 
long enough to overcome its birotation, is 

[«]z) = 52-5- 

In the ordinary souring of milk the lactose becomes converted into 
lactic acid. 

On heating lactose with dilute acids it undergoes inversion, forming 
dextrose and galactose in accordance with the formula given on p. 565, 
illustrating the inversion of cane sugar. 

Milk sugar is of considerable importance by reason of the large amount 
used of late in the preparation of modified milk for infant feeding. 

Grape sugar and cane sugar are to be looked for as adulterants of 
milk sugar. 

The purity of milk sugar is best established by titrating against Feh- 
ling's solution, 10 cc. of which are equivalent to 0.067 gram of lactose. 

RAFFINOSE. 

Raflfinose, C18H32O165H2O, is a sugar belonging neither to the saccha- 
rose nor the glucose group, but to the so-called saccharoid group, the other 
members of which do not occur in foods. 

Raflfinose occurs in beet root molasses to the extent of from 3 to 4 
per cent. It is a crystalline, slightly sweet substance, soluble in water 
and slightly soluble in alcohol. It does not reduce Fehling's solution, 
but readily undergoes fermentation with bottom yeast. On inversion it 
splits up into levulose and melibiose (C12H22O11). 

The melting-point of raflfinose is 118° to 11*9° C. Its specific rotary 
power [a:lD== + 104.5 ^-t a temperature of 20° C. 

THE POLARISCOPE AND SACCHARIMETRY. 

A full discussion of the principles of polarized light and even a detailed 
description of their application to the polariscope will not be given here, 
but the reader who wishes full information along this line is referred to 



SUGAR AND SACCHARINE PRODUCTS. 



601 



the various treatises such as those of Browne * Landolt,t Rolfe,t 
Spencer, § Tucker, 1| and Wiechmann,^ in which ^various forms of 
polariscopes are described and their underlying principles discussed. 

The Soleil-Ventzke Saccharimeter is the one most commonly used 
in this country, being adopted as the standard for all United States govern- 
ment work. Fig. 102 shows this instrument, known as the half-shadow 
apparatus, in its simplest form with a single movable wedge in its com- 
pensating system. 

An excellent light for work with this instrument is that furnished by 
the Welsbach burner, a convenient form of lamp being shown in Fig. iii, 
in which the burner is inclosed in a sheet-metal chimney of suitable con- 




FiG. 102. — Single-wedge Saccharimeter. 



struction. An argand, gas, or kerosene burner may, however, be used, 
and in a late form of Schmidt and Haensch instrument. Fig. 103, a spe- 
cially constructed incandescent electric lamp is supplied. 

The International Commission for Uniform Methods of Sugar Analysis 
at its seventh session held at New York, 191 2, passed the following resolu- 
tion based on studies by A. H. Bryan: " Wherever white light is used in 
polarimetric determinations, the same must be filtered through a solution 
of potassium bichromate of such a concentration that the percentage con- 



* Handbook of Sugar Analysis, New York, 191 2. 

t Optical Rotation of Organic Substances, trans, by Long, Easton, 1902. 

t The Polariscope in the Chemical Laboratory, New York, 1905. 

§ Handbook for Sugar Manufacturers and their Chemists, New York, 1905. 

II Manual of Sugar Chemistry, New York, 1905. 

*if Sugar Analysis, New York, 1914. 



602 FOOD INSPECTION AND ANALYSIS. 

tent of the solution multiplied by the length of the column of solution in 
centimeters is equal to nine." 

The Single-wedge Saccharimeter. — The following description of the 
saccharimeter and directions for its use are from the revised regulations 
of the U. S. Internal Revenue Department. The tub-^ N, Fig. 102, con- 
tains the illuminating system of lenses and is placed next to the lamp; 
the polarizing prism is at O and the analyzing prism at H. The quartz 
wedge compensating system is contained in the portions of the tube marked 
FEG and is controlled by the milled head M. The tube / carries a small 
telescope, through which the field of the instrument is viewed, and just 
above is the reading-tube K, which is provided with a mirror and magnify- 
ing lens for reading the scale. 

The tube containing the sugar solution is shown in position in the 
trough between the two ends of the instrument. In using the instrument 
the lamp is placed at a distance of at least 200 mm. from the polarizing 
end; the observer seats himself at the opposite end in such a manner 
as to bring his eye in line with the tube /. The telescope is moved in or 
out until the proper focus is secured to give a clearly defined image, 
when the field of the instrument will appear as a round, luminous 
disk, divided into halves by a vertical line passing through its center, 
and darker on one half of the disk than on the other, when the com- 
pensating quartz wedge is displaced from the neutral position. If the 
observer, still looking through the telescope, will now grasp the milled 
head M and rotate it first one way and then the other, he will find 
that the appearance of the field changes, and at a certain point the 
dark half becomes light and the light half dark. By rotating the milled 
head delicately backward and forward over this point he will be able to 
find the exact position of the quartz wedge operated by it, in which the 
field is neutral, or of the same intensity of light on both halves. The 
three different appearances presented by the field are shown in Fig. 106, 
opposite page 605. 

One of the compensating quartz wedges is fixed and the other is 
movable, sliding one way or the other according as the milled head is 
turned, so that for different relative positions of the two wedges a different 
thickness of quartz is interposed in the path of the polarized ray. By 
tliis means the amount of the rotation which the sugar solution or other 
optically active substance examined exerts upon the light polarized by 
the prism at O may be, as it were, counteracted by varying the relative 
position of the wedges. 



SUGAR AND SACCHARINE PRODUCTS. 



603 



With the milled head set at the point which gives the appearance of 
the middle disk shown in Fig. io6, the eye of the observer is raised to the 
reading tube K, which is adjusted to secure a plain reading of the divisions, 
and the position of the scale is noted. It will be seen that the scale proper 
is attached to the quartz wedge, which is moved by the milled head; 
and attached to the other quartz wedge is a small scale called a vernier^ 
which is fixed, and which serves for the exact determination of the posi- 
tion of the movable scale with reference to it. On each side of the zera 
line of the vernier a space corresponding to nine divisions of the movable 
scale is divided into ten equal parts. By this device the fractional part 
of a degree indicated by the position of the zero line is ascertained in 




Fig. 103. — Double-wedge Soleil-Ventzke Saccharimeter, mounted on Bock Stand and 
provided with Incandescent Electric Lamp. 

tenths; it is only necessary to count from zero until a line is found which 
makes a continuous line with one on the movable scale. 

With the neutral field, as indicated above, the zero of the movable 
scale should correspond closely with the zero of the vernier, unless the 
zero point is out of adjustment. 

Adjusting the Instrument. — If the observer desires to secure an exact 
adjustment of the zero of the scale, or in any case if the latter deviates 
more than two-tenths of a degree, the zero lines are made to coincide by 
moving the milled head and securing a neutral field at this point by 



604 FOOD INSPECTION AND ANALYSIS. 

means of the small key which comes with the instrument, and which 
fits a small nipple on the left-h.a.nd side of Ff the fixed quartz wedge of 
the compensating system. This nipple must not be confounded with 
a similar nipple on the rlght-h.a,nd side of the analyzing prism H, which 
it fits as well, but which must never be touched, as the adjustment of 
the instrument would be seriously disturbed by moving it. With the 
key on the proper nipple it is turned one way or the other until the 
field is neutral. Unless the deviation of the zero be greater than 0.2° it 
will not be necessary to use the key, but only to note the amount of the 
deviation, and for this purpose the observer must not be content with 
a single setting, but must perform the operation five or six times and take 
the mean of these different readings. If one or more of the readings 
show a deviation of more than 0.2° from the general average they should 
be rejected as incorrect. Between each observation the eye should be 
allowed a moment of rest. 

The Scale usually has no equal divisions on one side of the zero fol 
reading right-handed polarization, and 20 equal divisions on the othei 
side for left-handed polarization. The scale is an arbitrary one, based 
on the plan that a normal aqueous solution of pure cane sugar (26.048 
grams made up to 100 cc.) will read exactly 100° or divisions to the right 
of the zero when polarized in a 200-mm. tube. 

The accuracy of various portions of the scale may be verified bf 
quartz control plates of varying thickness, usually mounted in tubes, 
the correct polariscopic reading of each of which plates has been accurately 
determined, this reading being as a rule marked on the tube. As the 
sugar value of such a quartz plate varies with the temperature, the 
temperature at which the particular reading marked thereon applies is 
usually specified, and in many cases a table giving its exact value at 
different temperatures from 10° to 35° accompanies the plate. 

The Double-wedge Saccharimeter is shown in Fig. 104, the arrangement 
of the optical parts being also shown. 

In this instrument the two sets of wedges employed are of oppo- 
site optical properties, so that extreme accuracy may be arrived at by 
making the readings with both, the inaccuracies of one being compen- 
sated for by the other. Ordinarily in using this form, one movable wedge, 
say the one controlled by the right-hand milled screw head, is set at zero, 
while the reading of the sugar solution or other substance to be polar- 
ized is made with the other movable wedge. 

The Triple-field Saccharimeter. — The latest form of saccharimeter 



SUGAR AND SACCHARINE PRODUCTS. 



605 




Fig. 104. — Triple-wedge, Triple-field Soleil-Ventzke Saccharimeter. 

is the triple-field instrument, the construction of the polarizer being 
shown in Fig. 105. 

In this form the analyzer is the same as in the fore- 
going instruments, but the polarizer consists of one large 
and two small Nicol prisms I, II, and III, the construction 
and arrangement being such that when the compensating 
wedges are at the neutral point, sections i, 2, and 3 of 
the circular field (corresponding respectively to the prisms 
I, II, and III) are evenly lighted, forming a circular 
uniformly colored field, while in any other position of I — 
the wedges section i is dark while 2 and 3 are light or 
vice versa. The accompanying diagram, Fig. 106, shows 
the appearance of the field of this instrument in the three 
positions of the quartz wedge, viz., at the neutral point 
and at both sides thereof. 

The lamp used for illumination should be separated 
from the polariscope on account of the influence of its Fig. 105. 

heat on the readings. This is best accomplished by 
having the lamp in a separate compartment from the polariscope, so 




606 , FOOD INSPECTION AND ANALYSIS. 

that both are on opposite sides of a partition, an opening in which trans- 
mits the Hght. In any event some kind of screen should be interposed 
between the two. Best resuks are obtained if the room in which the 
observations are made is dark. 

Comparisons of Scales of Various Polariscopes. — Besides the Soleil- 
Ventzke instrument, there are various other forms of polariscope. Among 
the best known of these are Laurent's, Wild's, and Duboscq's, all of 
which are made with scales reading in circular degrees, while in some 
cases modified forms have scales in which, like the Soleil- Ventzke, per- 
centages of sugar are directly read off. Some instruments are provided 
with double scales reading both circular degrees and percentages of sugar, 
and in certain of the Duboscq instruments additional scales for percent- 
ages of milk sugar and diabetic sugar are provided. 

In the Wild, Duboscq, and Laurent instruments the source of light 
is the sodium flame, yielding what is termed a monochromatic light. 
This is produced by fused sodium cliloride passing through a Bunsen 
flame, various mechanical devices being employed for making the light 
continuous. In the Ventzke instrument, as was stated above, the ordinary 
light from a bright gas or oil flame is used. 

For convenience in conversion of readings on one instrument to their 
equivalents on other scales, the following factors can be used: 

r° Ventzke =0.3468° angular rotation Z). 

° angular rotation Z) =2.8835° Ventzke. 

° Ventzke =2.6048° Wild (sugar scale). 

° Wild (sugar scale) =0.3840° Ventzke. 

° " " " =^.1331° angular rotation Z). 

° angular rotation D =7.5110° Wild (sugar scale) 

° Laurent (sugar scale) =0.2167° angular rotation Z). 

° angular rotation D =4.6154° Laurent (sugar scale). 

° Soleil-Duboscq =0.2167° angular rotation £>. 

° " " =0.2450° " " ;'. 

° " " =0.620° Soleil- Ventzke. 

° " " =1.619° Wild. 

° Soleil-Ventzke =1.608° Soleil-Duboscq (old scale). 

° " " =1.593° " " (new scale). 

° Wild =0.611° " " (Wild normal weight 10). 

o li ^j_223° " " ( " " " 20). 

Normal Weights of Sugar for Different Instruments. — The follow- 
ing normal weights (number of grams in 100 cc. at 17.5° C.) are those on 
which the scales of the various instruments are based: Soleil-Ventzke, 
26.048; Soleil-Duboscq 16.29 (formerly 16.19); Wild, usually, 10 or 20; 
Laurent, 16.29. 

The International Commission for Uniform Methods in Sugar Analysis 
has decided to use for the Ventzke scale 26 grams and make up at 20° C. 
to 100 metric cc, which figures are approximately equivalent to 26.048 



SUGAR AND SACCHARINE PRODUCTS. 607 

grams made up to loo Mohr cc. Unless otlierwise stated the term normal 
weight as here used refers to 26 grams. 

At the date of writing Browne and other prominent American sugar 
chemists are advocating the adoption of an international weight of 20 grams 
and a scale to correspond. This change, which is in the interest of sim- 
plicity, is endorsed also by leading French and English authorities. 

Specific Rotatory Power.— This is a theoretical term to express a stand- 
ard by which the various optically active substances may be compared, 
and is understood to mean the amount in angular degrees through which 
the plane of polarization of a ray of light of stated wave length is rotated 
by I gram of a given substance in aqueous solution of i cc. and forming 
a column i decimeter in length. The actual rotatory power of a solution 
varies directly with the length of the column traversed by the light, with 
the concentration of the solution, and with the wave length of light, 
hence the need of a purely theoretical basis for purposes of comparison. 

The specific rotatory power is usually expressed as [ajo or [a]j, the 
letters D or ; indicating the character of the light. Thus, D indicates 
the monochromatic light obtained from the sodium flame, named from the 
D line of Fraunhofer in the yellow portion of the spectrum, while j (from 
the French jaime) indicates what is known as the transition tint, the 
rose-purple color produced when ordinary white light passes through 
the polarizer and analyzer, placed with then: principal sections parallel 
to each other and with r plate of quartz 3.75 mm. thick interposed between 
them.* 

The specific rotatory power is determined as follows: 

[a]D or [a]j = -^, 

where a = observed angular rotation, 

<; = grams of the substance in 100 cc. of the solution, and 
/ = length of the observation-tube in decimeters; or in cases where, 
instead of the grams per 100 cc, the percentage composition is known 
(expressed by ^ = grams of the substance in 100 grams of the solvent), 



and the specific gravity (expressed by d), then [a]r, or [a]j = 



looa 
~pdi' 



* Some confusion is caused by the adoption of the characters D and j, since both would 
naturally seem to indicate yellow light. The so-called transition tint above defined is, how- 
ever, complementary to the mean yellow, or jaune moyen, and it is the complementary color 
and not the yellow itself that is indicated by the character j. 



608 FOOD INSPECTION AND ANALYSIS. 

Birotation.— In polarizing solutions of all the common sugars other 
than sucrose the phenomenon of birotation should be taken into account, 
whereby a change in optical activity is shown by standing. Thus, solu- 
tions of dextrose, levulose, and lactose polarize much higher when freshly 
prepared than after long standing, requiring in some instances several 
hours before the lowest or normal figure is reached. Maltose, on the 
other hand, increases in polarization after standing in solution. By 
boiling the solution it may at once be brought to its correct reading. The 
desired result may also be accomplished by adding a few drops of ammo- 
nia, either treatment being resorted to before the solution is made up to 
the required volume. 

ANALYSIS OF CANE SUGAR AND ITS PRODUCTS. 

Qualitative Tests for Sucrose. — (a) Polariscope Test. — The substance 
to be tested, if not already in solution, is dissolved in water, and if the 
solution is not perfectly clear, is clarified by the addition of alumina 
cream or by subacetate of lead (page 6io) and filtered. An observation 
tube is filled with the clear solution and the polariscope reading noted. 
A measured portion of the same solution is then treated with one-tenth its 
volume of concentrated hydrochloric acid and is subjected to inversion 
(page 6ii), after which the same tube as before is filled with the inverted 
solution and a second reading obtained, one-tenth of the observed reading 
being added for the true invert polariscopic reading. If the two readings 
are virtually the same, sucrose is absent, but, in the presence of sucrose, 
the second reading will be considerably lower than the first or may even 
be to the left of the zero. 

(6) Test with Nitrate of Cobalt.^ — Prepare a 5% solution of cobaltous 
nitrate, and a 50% solution of potassium hydroxide. If the sugar solution 
to be tested contains dextrin or gums, these should be first removed by 
treatment with alcohol. 15 cc. of the sugar solution to be tested are mixed 
with 5 cc. of the cobaltous nitrate reagent, and 2 cc. of the potassium 
hydroxide solution are added. Sucrose produces under these conditions 
a permanent amethyst-blue color, while dextrose gives at first a turquoise- 
blue passing over into light green. In a mixture of the two sugars the 
color due to sucrose will predominate. 

According to Wiley, i part of sucrose in 9 parts of dextrose may be 

* Wiley, Ag. Anal., p. 189. 





Fig. io6. — Appearance of the Field in the Half-shade (above) and Triple-shade (below) 

Saccharimeter. 



SUGAR AND SACCHARINE PRODUCTS. 609 

detected by this test. Browne * notes that other sugars give a similar 
coloration, hence the test is not infalHble although a useful guide. 

Analysis of Cane Sugar.— In the case of commercial granulated or 
loaf sugar the sucrose determination is usually all that is necessary to 
determine its purity, and the same is true, as a rule, of the powdered 
white sugars. A fahly complete analysis of raw or brown sugar con- 
sists in the determinations of moisture, sucrose, invert sugar, ash, organic 
non-sugars, and quotient of purity. Care should be taken that the por- 
tion subjected to analysis is a fair representation of the whole, and is 
perfectly homogeneous. 

Determination of Moisture. — Two to five grams of the sample are dried 
in a flat, tared metal dish, to constant weight in vacuo, or in a McGill 
oven t in a current of ah, at about 70° C, at which temperature levulose 
is not decomposed. For ordinary purposes drying to constant weight 
in a boiling-water oven is sufhciently accurate. 

Determination of Ash. — The residue from the moisture determination 
is burned slowly and cautiously over a low flame until frothing has ceased. 
Afterwards increase the flame and ignite to a white ash at a low red heat, 
preferably in a muffle furnace. 

In igniting saccharine substances. which contain an appreciable amount 
of cane sugar, the contents of the dish will swell up and froth, unless 
great care be taken, to such an extent as to flow over the sides of the dish, 
occasioning loss and inconvenience. Such frothing may be largely held 
in check by directing the flame at first down from above upon the pasty 
mass, instead of from under the dish as ordinarily, till all is reduced to a 
dry char, afterwards continuing the ignition from below in the usual 
manner. 

Organic Non-sugars. — These consist mainly of compounds of organic 
acids, together with gum, coloring matter, albuminous bodies, etc. They 



* Sugar Anal., p. 681. 

t A. McGill, Laboratory of Inland Revenue, Ottawa, Canada, has devised a forced- 
draft water-oven for drying at temperatures between 60° and 90° C. The oven is heated 
by means of ordinary gas-burners, and the temperature is controlled by introducing at the 
bottom of the oven a blast of air from a blower run by a small water-motor. Before dis- 
charging into the oven, the air-tube enters the water-chamber and is coiled a number of 
times in order to sufficiently warm the air before it enters the oven. The exit end of tlie 
air-tube is covered with a concavo-convex disk in order to distribute the blast and to pre- 
vent harmful currents. By regulating the burners and the flow of air, a fairly constant tem- 
perature can be obtained. The bottom of the oven is curved instead of flat, to prevent 
bumping when the water is boiling; a perforated plate serves as a false bottom. 



610 FOOD INSPECTION AND ANALYSIS. 

are determined by difference between ioo% and the sum of the sucrose, 
invert sugar, moisture, and ash. 

Quotient of Purity. — By this term is meant the percentage of pure 
sugar in the dry substance. It is calculated by dividing the per cent 
of sucrose by the percentage of total solids and multiplying the result by loo. 

Determination of Sucrose by the Polariscope. — Reagents. — (a) Lead- 
Suhacetate Solution.* — Boil for half an hour 430 grams of normal lead 
acetate, 130 grams of litharge, and 1000 cc. of v^ater, allow to cool and 
settle. Dilute the supernatant liquid to 1.25 specific gravity with recently 
boiled water. 

Anhydrous lead subacetate, first proposed by Horne,t may be sub- 
stituted for the solution. 

{b) Alumina Cream. — Divide a cold, saturated solution of alum into 
two unequal portions, add to the larger a slight excess of ammonia, then 
by degrees the remaining portion to faint acid reaction. 

Process. — If the Soleil-Ventze polariscope is to be used, weigh out 
26 grams of the sugar, which may conveniently be done in the German- 
silver, tared tray especially designed for this purpose (Fig. 107). If any 




Fig. 107. German-silver Sugar-tray with Tare. 

other instrument is employed, weigh out the standard or normal weight 
for that instrument (see page 606). Transfer the sugar by washing to a 
loo-cc. graduated sugar-flask, and if the solution is perfectly clear, as 
would be the case with a refined sugar, make up to the mark and shake 
to insure a uniform solution. If the solution is slightly turbid, or more 
or less opaque or dark-colored, a clarifier must be added before making 
up to the mark to obtain a clear solution for polarization. The kind 
and amount of clarifier to be used depends on the nature of the sugar 
solution and must be learned by experience. If the turbidity is only slight, 
from 5 to 10 cc. of alumina cream alone will often prove sufficient; if 



* U. S. P. lead subacetate, sometimes sold as Goulard's extract, may also be used. 
t Jour. Am. Chem. Soc, 26, 1904, p. 186. 



SUGAR AND SACCHARINE PRODUCTS. 611 

more opaque, lo cc. of lead subacetate solution or a small amount of 
the dry salt may be used. 

For additional details as to clarification see page 644, under Molasses. 

After adding the clarifier, the flask is filled to the mark with water 
and shaken, the solution being poured upon a dry filter and the first 
few cubic centimeters of the filtrate rejected. A 2oo-mm. observation- 
tube is filled with the clear sugar solution and the polarization noted. 
If sucrose is the only optically active substance present, the direct reading 
on the polariscope will indicate its percentage. 

Inversion by the Clerget-Herzfeld Method. — In the presence of invert 
or other sugars the normal solution is subjected to inversion as follows: 
Free a portion of the solution from lead by treating with anhydrous 




Fig. 108. — A Convenient Sugar-scale. 

sodium carbonate, sodium sulphate or potassium oxalate, filter, place 
50 cc. in a loo-cc. flask, add 25 cc. of water and little by little, while 
rotating the flask, 5 cc. of 38.8% hydrochloric acid. Heat in a water 
bath at 70° C, so that the solution in the flask reaches 67° to 69° C. in 
2\ to 3 minutes. Maintain at 69° C. during 7 to 7I minutes, making a total 
time of heating of 10 minutes. Remove the flask, cool the contents rapidly 
to 20° C, and dilute to 100 cc. Polarize this solution in a 200-mm. tube 
provided with a lateral branch and a water jacket, passing a current of 
water around the tube to maintain a temperature of 20° C. 

The inversion may also be accomplished by allowing a mixture of 
50 cc. of the clarified solution, freed from lead, and 5 cc. of the acid to 
stand for 24 hours at no less than 20° C. or for 10 hours at not less than 25°. 

The sucrose is obtained by the Clerget-Herzfeld formula based on the 
rotation of cane sugar before and after inversion, 

^_ ioo{a-h) 
142.66— // 2' 



612 FOOD INSPECTION AND ANALYSIS. 

where 5 = per cent of sucrose, a = direct polarization, &-- invert polari- 
zation, and / = temperature. Note that if the direct polarization is to 
the right or positive, and the invert to the left or negative, then a—h would 
be the sum of the two polarizations. 

In many cases where it is almost impossible to obtain a colorless solu- 
tion for polarization in the 200-mm. tube, a loo-mm. tube may be employed, 
and the readings multiplied by 2, or half the normal weight,* viz., 13 
grams of the sample may be taken and made up to 100 cc, the 200-mm. 
tube employed, and the readings multiplied by 2. 

The determination of sucrose by the Clerget-Herzfeld formula is 
applicable to all mixtures of the common sugars excepting those in which 
lactose, or milk sugar, is present. 

Theory of Inversion. — On page 586 a reaction is given showing that 
when sucrose is subjected to inversion by the action of dilute acids or 
of invertase or yeast it splits up into the two sugars dextrose and le\ailose, 
forming equal quantities of each. The dextrose is, however, dextro- 
rotatory and the levulose laevorotatory. Invert sugar is the term applied 
to the mixture of dextrose and levulose formed by the inversion of sucrose. 
The specific rotatory power of sucrose varies so little with the temperature 
as to be regarded for practical purposes as constant. At 87° a solution 
of invert sugar polarizes at zero. This is due to the fact that the rotatory 
power of levulose, unlike that of sucrose and dextrose, varies with the 
temperature. At from 87° to 88° the left-handed rotation of the levulose 
balances the right-handed rotation of the dextrose in the invert sugar, 
hence the zero reading. As the temperature decreases from 87°, the 
rotatory power of the levulose proportionally increases, till at 0° the normal 
invert sugar solution would polarize —42.66. On these facts the Cherget- 
Herzfeld formula is based, assuming that a normal solution of pure cane 
sugar polarizes + 100, while after inversion the reading for 0° temperature 
would be —42.66 and would decrease 0.5 for each degree in temperature 
above 0°. Thus at 20° the invert reading would be —32.66. 

Neutralization of the free acid after inversion is sometimes practiced 
to avoid the disturbing influence of mineral acid on the polarization of 
c?-fructose as well as of certain impurities present in molasses, juices, etc. 

* Wherever the term " normal weight " occurs hereafter will be meant, unless otherwise 
noted, the normal weight of sugar for the Soleil-Ventzke polariscope, viz., 26 grams, and 
by a " normal solution " will be meant 26 grams in 100 cc. of water at 20° C. Clerget's 
formula, as originally worked out by him, was not based on this normal weight, but on 
16.35 grams. It is, however, applicable to 26 grams. 



SUGAR AND SACCHARINE PRODUCTS. 613 

When neutralization is practiced the factor in the Clerget-Herzfeld formula 
should be 141. 7 instead of 142,66.* Neutralization, however, introduces 
another disturbing factor, namely sodium chloride, to counterbalance which 
Saillard f adds an equivalent amount of this salt to the solution used for 
direct polarization. The most rational system of defecating and inverting is 
that proposed by Deerr.| He employs for defecation barium hydroxide 
in conjunction with a acid reagent containing aluminum sulphate and 
sulphuric acid in such proportions that the two solutions neutralize each 
other forming aluminum hydroxide and barium sulphate. After direct 
polarization of the filtered solution inversion is carried on with another 
portion of the acid reagent, then an equivalent amount of barium hydroxide 
is added thus again precipitating all added substances. 

Detection of Invert Sugar. — Methyl-bhie TesL§ — This test depends 
on the decolorization of methyl blue by invert sugar. Twenty grams of 
sugar are dissolved in water and made up to 100 cc. If the solution is not 
clear, sufficient subacetate of lead solution is added to clarify before making 
up to the mark, and the solution is filtered. Add to the filtrate enough 
10% sodium carbonate solution to make alkaline, and filter a second time. 
Take about 50 cc. of the filtrate in a casserole, add 2 drops of a 1% solu- 
tion of methyl blue, and boil over a free flame, noticing particularly the 
time the solution begins to boil. 

If the color disappears in one minute after boiling, there is present 
at least 0.01% of invert sugar. If it is not completely decolorized by 
3 minutes' boiling, no invert sugar is present. 

Determination of Invert Sugar in Cane Sugar Products by the Polar- 
iscope. — While invert sugar is best determined by Fehling's solution as 
described elsewhere, it may be approximately estimated by the polari- 
scope, though less satisfactorily. On page 671 a method is given for the 
determination of levulose by polariscopic readings at two different tem- 
peratures. Since invert sugar is composed of equal parts by weight of 
dextrose and levulose, the percentage of levulose multiplied by 2 would 
give that of invert sugar. 

Test for Ultramarine in Sugar.[[ — A large amount of the sugar is 
dissolved in water and the coloring matter is allowed to settle out, wash- 

* Browne, Handbook of Sugar Analysis, New York, 1912, p. 271. 

t 8th Int. Cong. App. Chem., 27, 1912, p. 63. 

t Int. Sugar Jour., 17, 191 5, p. 179. 

§ Wiechmann, Sugar Analysis, New York, 1914, p. no. 

||Leffmann and Beam, Select Methods of Food Analysis, p. 126. 



614 FOOD INSPECTION AND ANALYSIS. 

ing the residue several times by decantation. On treatment with hydro- 
chloric acid, the blue color is discharged if due to ultramarine. 

SUGAR DETERMINATION BY COPPER REDUCTION. 

Various convenient methods of determining sugars depend on the 
readiness with which certain of them, known as reducing sugars, act on 
copper salts, especially on the tartrate of copper, reducing it to cuproui- 
oxide. 

This reducing power is exercised in a definite degree under fixe " 
conditions, so that the amount of reducing sugar present may be accuratel 
determined. Of the common sugars, sucrose is the only one that has 
practically no dnect reducing action, but on undergoing inversion it is con- 
verted into reducing sugars, which are readily determined. 

Use of Fehling's Solution. — There are various well-known mixtures 
of copper sulphate, tartaric acid salts (usually Rochelle salts or cream 
of tartar), and alkalies, called after chemists who have employed them 
in the determination of the reducing sugars, each one possessing certain 
advantages, but none have become so widely adopted as Fehling's solu- 
tion, the use of which in one form or another is now well-nigh universal. 

There are a number of methods by which Fehling's solution is employed 
for this purpose, both volumetric and gravimetric. The former are 
simpler and quicker of manipulation, and thus are preferable for com- 
mercial work where extreme accuracy is not required. The gravimetric 
methods are usually considered more delicate and accurate, calling for 
less skill, but more time in arriving at results, and with less of the " per- 
sonal element " than the volumetric. 

Some modifications of the Fehling methpd, especially as carried out 
gravimetrically, differ for the various reducing sugars to be determined, 
and others are carried out alike, so far as manipulation is concerned, 
whether the particular sugar to be determined be dextrose, maltose, or 
lactose. 

While, strictly speaking, the reducing power of dextrose, levulose, and 
invert sugar are not identical, it is customary in commercial work to 
regard them as such, and no appreciable error arises in consequence 
except in extreme cases. Thus the term " reducing sugars " is com- 
monly applied indiscriminately to dextrose, levulose, and invert sugar, 
the same factor being used in calculating either, in mixtures wherein 
other reducing sugars, as lactose, maltose, etc., having widely different 
reducing powers are absent. 



SUGAR AND SACCHARINE PRODUCTS. 615 

Fehling's solution is made up in two separate parts as follows: 

A. Fehling's Copper Solution. — 34.639 grams of carefully selected 
crystals of pure copper sulphate dissolved in water and diluted to exactly 
500 cc. 

B. Fehling's Alkaline Tartrate Solution.— ij^ grams Rochelle salts 
and 50 grams sodium hydroxide are dissolved in water and diluted to 
exactly 500 cc. 

The Fehling solution should be standardized by dissolving 0.5 gram 
of pure anhydrous dextrose in water, and diluting to exactly 100 cc. Ten 
cubic centimeters of this dextrose solution should exactly reduce the copper 
in 10 cc. of the Fehlmg (5 cc. each of solutions A and B) when conducted 
according to the volumetric process described below. 

Volumetric Fehling Process. — For determining dextrose, levulose, 
or invert sugar, prepare a clarified, deleaded, and neutralized solution of the 
sugar of such a strength that an accurately weighed amount dissolved in 
water and made up to 100 cc. shall not contain more than 1% of the 
reducing sugar, as nearly as can be estimated with or without a rough 
preliminary titration. For the determination of lactose or maltose a 
i|% solution may be used. 

Measure accurately into a flask of about 250 cc, capacity 5 cc. Feh- 
ling's copper sulphate solution. A, and 5 cc. of the alkaline solution, B. 
Add about 40 cc. of water, mix and boil over a free flame, with copper 
gauze beneath the flask. While still boiling, add from a pipette or burette 
a measured quantity of the sugar solution, prepared as above, until the 
copper after three minutes' boiling is all reduced to cuprous oxide. The 
end-point is determined in a variety of ways. Practice will soon enable 
the eye to judge the near approach of the end- point by the changes in color 
that take place in the solution, which turns from a deep blue, first to green, 
then to a dull-red tint, and finally to a bright brick-red. The sugar- 
containing solution may be added from the burette quite rapidly until 
the solution reaches the dull-red tint, after which care is taken to add a 
little at a time, keeping account of the total amount added. If the flask 
be removed from the flame, and the bright, diffused light from a window 
viewed through the solution with the eye on a level with the surface, a thin 
film scarcely wider than a line will be observed just below the surface 
(see Fig. 109), which is blue so long as some of the copper in the solu- 
tion remains unreduced. When, however, all the copper has been reduced, 
this film ceases to be blue and becomes colorless or yellow. 

If the film is not at once apparent, it may often be made quite notice- 



^ 



616 



FOOD INSPECTION AND ANALYSIS. 




able by simply diluting the solution in the flask with water. At the approach 
of the end-point the sugar-containing solution should be added a very little 
at a time. The exact end-point is best arrived at by filtering off a few drops 
of the liquid, acidifying the filtrate with acetic 
acid, and adding a drop of a solution of ferrocy- 
anide of potassium. As long as there is unreduced 
copper present, a precipitate or brown-red colora- 
tion will appear when the ferrocyanide is added. 
The testing is greatly facilitated by lowering a 
small filter into the liquid by means of forceps 
and removing a small portion of the clear solu- 
tion thus obtained with a medicine dropper (B. B. 
Ross) . The sugar solution toward the end should 
be added to the contents in the flask in small in- 
stallments (say half a cubic centimeter each time), 
boiling the liquor for at least three minutes after 
each addition, until no brown-red coloration is 
produced by adding the ferrocyanide to a little 
of the filtered acidified liquid. When the number 
of cubic centimeters of sugar solution necessary 
to reduce the copper has thus been determined, a 
second titration should be made to verify the first, 
running the entire amount of sugar-containing 
liquid found necessary in the first case into the second flask. 

The equivalents of lo cc. of the mixed alkaline copper solution in the 
above method are, in terms of the common reducing sugars, as follows: 

0.05 gram of invert sugar, dextrose, or levulose; 
0.0475 gram of cane sugar after inversion; 
0.0807 gram of maltose; 
0.067 gram of lactose. 

Suppose, for example, a sample of brown sugar is to be examined 
for invert sugar. This class of sugar has usually from 2 to 6 per cent 
of invert sugar. Hence, if 10 grams of the sample are dissolved in 100 
cc, the resulting solution will contain not more than 1% of invert 
sugar. 

Suppose 12.9 cc. of this 10% sugar solution were found by the above 
process to reduce 10 cc. of Fehling's solution. 

10 cc. Fehling's solution are equivalent to 0.05 gram i;ivert sugar. 



Fig. 109. — Flask and Con- 
tents used in Volumetric 
Fehling Determinations. 
Showing layer just be- 
neath the surface, the 
color of which indicates 
the end-point in adding 
the sugar-containing li- 
quid. 



SUGAR AND SACCHARINE PRODUCTS. 617 

Therefore 12.9 cc. of the sugar solution contain 0.05 gram invert- 
sugar. 

100 cc. sugar solution contain 10 grams sample, and 12.9 cc. contain 

1.29 grams sample, the equivalent of 0.05 gram invert sugar. 

„ . 0.05X100 
Hence per cent mvert sugar = = 3-9- 

GRAVIMETRIC Fehling PROCESSES.— In determining reducing sugars 
by gravimetric processes, a measured volume of the sugar solution is 
allowed to act upon a measured volume of hot Fehling's solution for a 
fixed time, thus forming cuprous oxide. This may be dried and weighed 
direct, but is more commonly converted either into cupric oxide by ignition, 
or into metallic copper by reduction with hydrogen or by electrolysis. 
In any case the sugar is calculated from the weight of the cuprous oxide, 
the cupric oxide, or the metallic copper (whichever method be used) by 
the employment of the proper factor, or by the use of tables compiled 
for the purpose. 

Note. — Much difference of opinion exists as to the best and most 
accurate Fehling gravimetric method to employ. For the determination 
of dextrose, the Association of Official Agricultural Chemists has given 
its approval to the AUihn method, wherein the cuprous oxide deposited 
is further reduced to metallic copper and the dextrose calculated from 
the copper by Allihn's table. 

The author for two reasons prefers the method of O'Sullivan as 
employed by Defren, with the use of the Defren tables, in accordance 
with which the reducing sugar is expressed in terms of its equivalence 
to cupric oxide, first because of its comparative simplicity, involving as it 
does less processes than the Allihn method (each additional process 
introducing a possible source of error), and, second, because the same 
method as carried out is applicable for the determination not only of 
dextrose, but also of maltose and lactose, Defren having worked out 
tables adopted for them all. Munsen and Walker* have also devised a 
simple method with accompanying tables, adapted, with a uniform system 
of procedure, to the determination of the various reducing sugars. In 
using the tables for dextrose, maltose, and lactose compiled by Allihn, 
Wein, and Soxhlet, the method employed must in each case be carried out 
in strict accordance to the minutest details adopted by each of the above 
authorities, and they are by no means uniform. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.), p. 241. 



618 FOOD INSPECTION AND ANALYSIS. 

The Defren-O'Sullivan Method.* — Mix 15 cc. of Fehling's copper 
solution A (page 615), with 15 cc. of the tartrate solution, ^, in a quarter- 
liter Erlenmeyer flask, and add 50 cc. of distilled water. Place the flask 
and its contents in a boiling water bath and allow them to rerhain five 
minutes. Then run rapidly from a burette into the hot liquor in the 
flask 25 cc. of the sugar solution to be tested (which should contain not 
more than one-half per cent of reducing sugar). Allow the flask to remain 
in the boiling water bath just fifteen minutes after the addition of the 
sugar solution, remove, and with the aid of a vacuum filter the contents 
rapidly in a platinum or porcelain Gooch crucible containing a layer 
of prepared asbestos filler about i cm. thick, the Gooch with the asbestos 
having been previously ignited, cooled, and weighed. The cuprous 
oxide precipitate is thoroughly washed with boiling distilled water till 
the water ceases to be alkaline. 

The asbestos used should be of the long-fibered variety, and should 
be specially prepared as follows: Boil first with nitric acid (specific 
gravity 1.05 to i.io), washing out the acid with hot water, then boil with 
a 25% solution of sodium hydroxide, and finally wash out the alkali with 
hot water. Keep the asbestos in a wide-mouthed flask or bottle, and 
transfer it to the Gooch by shaking it up in the water and pouring it 
quickly into the crucible while under suction. 

Dry the Gooch with its contents in the oven, and finally heat to dull 
redness for fifteen minutes, during which the red cuprous oxide is con- 
verted into the black cupric oxide. If a platinum Gooch is used (and 
this variety is preferred by the writer), it may be heated directly over 
the low flame of a burner. If the Gooch is of porcelain, considerable 
care must be taken to avoid cracking the crucible, the heat being increased 
cautiously and the operation preferably conducted in a radiator or muffle. 
After oxidation as above, the crucible is transferred to a desiccator, cooled, 
and quickly weighed. From the milligrams of cupric oxide, calculate 
the milligrams of dextrose from the following table: 

* Jour. Am. Chem. Soc, 18, 1896, p. 749, and Tech. Quart., 10, 1897, p. 167. 



1 



SUGAR AND SACCHARINE PRODUCTS. 



619 



DEFREN'S TABLE FOR THE DETERMINATION OP DEXTROSE, MALTOSE, 

AND LACTOSE. 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrains 


Milligrams 

of Cupric 

O.xide. 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of De.xtrose. 


of Maltose. 


of Lactose. 


3° 


13.2 


21-7 


18.8 


80 


35-4 


58-1 


50-5 


31 


^3-7 


22.4 


19-5 


81 


35-9 


58-9 


5I-I 


32 


14. 1 


23.1 


20.1 


82 


36-3 


59-6 


51-7 


33 


14.6 


23-9 


20.7 


83 


36.8 


60.3 


52-4 


34 


15-0 


24.6 


21.4 


84 


37-2 


61. 1 


53-0 


35 


15-4 


25-3 


22.0 


85 


37-7 


61.8 


53-6 


36 


15-9 


26.1 


22.6 


86 


38.1 


62.5 


54-3 


37 


16.3 


26.8 


23-3 


87 


38-5 


63-3 


54-9 


38 


16.8 


27-5 


23-9 


88 


39-0 


64.0 


55-5 


39 


17.2 


28.3 


24-5 


89 


39-4 


64.7 


56.2 


40 


17-6 


29.0 


25.2 


90 


39-9 


65-5 


56.8 


41 


18. 1 


29.7 


25-8 


91 


40.3 


66.2 


57-4 


42 


18.5 


30-5 


26.4 


92 


40.8 


66.9 


58-1 


43 


19.0 


31.2 


27.1 


93 


41.2 


67.7 


58-7 


44 


19.4 


31-9 


27-7 


94 


41.7 


68.4 


59-3 


45 


19.9 


32-7 


28.3 


95 


42.1 


69.1 


60.0 


46 


20.3 


33-4 


29.0 


96 


42.5 


69.9 


60.6 


47 


20.7 


34-1 


29.6 


97 


43-0 


70.6 


61.2 


48 


21.2 


34-8 


30.2 


98 


43-4 


71-3 


61.9 


49 


21.6 


35-5 


30.8 


99 


43-9 


72.1 


62.5 


50 


22.1 


36.2 


31-5 


100 


44-4 


72.8 


63-2 


51 


22.5 


37-0 


32.1 


lOI 


44-8 


73-5 


63.8 


52 


23.0 


37-7 


32-7 


102 


45-3 


74-3 


64-4 


53 


23 -4 


38.4 


33-3 


103 


45-7 


75-0 


65.1 


54 


23.8 


39-2 


34-0 


104 


46.2 


75-7 


65-7 


55 


24.2 


39-9 


34-6 


105 


46.6 


76-5 


66.3 


56 


24-7 


40-5 


35-2 


106 


47.0 


77-2 


67.0 


57 


25-1 


41-3 


35-9 


107 


47-5 


77-9 


67.6 


58 


25-5 


42.1 


36-5 


108 


48.0 


78.7 


68.2 


59 


26.0 


42.8 


37-1 


109 


48.4 


79-4 


68.9 


60 


26.4 


43-5 


37-8 


no 


48-9 


80.1 


69-5 


61 


26.9 


44-3 


38-4 


III 


49-3 


80.9 


70.1 


62 


27-3 


45-0 


39-0 


112 


49-8 


81.6 


70.8 


63 


27.8 


45-7 


39-7 


"3 


50.2 


82.3 


71-4 


64 


28.2 


46-5 


40.3 


114 


50-7 


83.1 


72.0 


65 


28.7 


47-2 


40.9 


"5 


51 -I 


83.8 


72-7 


66 


29.1 


47-9 


41.6 


116 


51.6 


84-5 


73-3 


67 


29-5 


48.6 


42.2 


117 


52.0 


85-2 


74.0 


68 


30.0 


49-4 


42.8 


118 


52-4 


85-9 


74-6 


69 


30-4 


50.1 


43-5 


119 


52-9 


86.6 


75-2 


70 


30-9 


50.8 


44-1 


120 


53-3 


87.4 


75-9 


71 


31-3 


51.6 


44-7 


121 


53-8 


88.1 


76.6 


72 


31.8 


52-3 


45-4 


122 


54-2 


88.9 


77.2 


73 


32.2 


53-0 


46.0 


123 


54.7 


89.6 


77-9 


74 


32.6 


53-8 


46.6 


124 


55-1 


90-3 


78-5 


75 


33-1 


54.5 


47-3 


125 


55-6 


91. 1 


79. r 


76 


33-5 


55-2 


47-9 


126 


56.0 


91.8 


79.8 


77 


34-0 


56.0 


48.5 


127 


56.5 


92-5 


80.4 


78 


34-4 


56-7 


49-2 


128 


56.9 


93-3 


81. 1 


79 


34-9 


57-4 


49-8 


129 


57-3 


94-0 


81.7 



620 



FOOD INSPECTION AND ANALYSIS. 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 
AND LACTOSE— {Continued). 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams > 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of Dextrose. 


of Maltose. 


of Lactose. 


130 


57-8 


94-8 


82.4 


180 


80.4 


131-8 


114. 6 


1,31 


58.2 


95-5 


83.0 


181 


80.8 


132-5 


115.2 


132 


58.7 


96.2 


83.6 


182 


81.3 


133-2 


115.8 


^33 


59-1 


97-0 


84.2 


183 


81.8 


134-0 


116.5 


134 


59-6 


97-7 


84-9 


184 


82.2 


134-7 


117. 1 


135 


60.0 


98-4 


85-5 


185 


82.7 


13--5 


117. 8 


136 


60.5 


99.2 


86.1 


186 


83.1 


136.2 


118. 4 


137 


60.9 


99.9 


86.8 


18/ 


83-5 


136.9 


119. 1 


138 


61-3 


100.7 


87.4 


188 


84.0 


137-7 


"9-7 


139 


61.8 


101.4 


88.1 


189 


84-4 


138.4 


120.4 


140 


62.2 


102. 1 


88.7 


190 


84-9 


139-I 


121. 


141 


62.7 


102.8 


89-3 


191 


85-4 


139-9 


121. 7 


142 


63.1 


103-5 


90.0 


192 


85-9 


140.6 


122.3 


143 


63.6 


104.3 


90.6 


193 


86.3 


141.4 


123.0 


144 


64.0 


105.0 


91-3 


194 


86.8 


142.1 


123.6 


145 


64-5 


105.8 


91.9 


195 


87.2 


142.8 


124-3 


146 


64.9 


106.5 


92.6 


196 


87.7 


143.6 


124.9 


147 


65-4 


107.2 


93-2 


197 


88.1 


144-3 


125.6 


148 


6s. 8 


108.0 


93-9 


198 


88.6 


145 -I 


126.2 


149 


66.3 


108.7 


94-5 


199 


89.0 


145-8 


126.9 


150 


66.8 


109.5 


95-2 


200 


89-5 


146.6 


127.5 


151 


67-3 


no. 2 


95-8 


201 


89.9 


147-3 


128.2 


152 


67-7 


III.O 


96-5 


202 


90.4 


148.1 


128.8 


153 


68.3 


III. 7 


97-1 


203 


90.8 


148.8 


129-5 


154 


68.7 


112. 4 


97-8 


204 


91-3 


149-6 


130. 1 


155 


69.2 


113. 2 


98.4 


205 


91.7 


150.3 


130.8 


156 


69.6 


113-9 


99-1 


206 


92.2 


151.1 


131-5 


157 


70.0 


114. 7 


99-7 


207 


92.6 


151.8 


132.1 


158 


70-5 


115-4 


100.4 


208 


93-1 


152-5 


132.8 


159 


70.9 


116. 1 


101.0 


209 


93 -S 


153-3 


133-4 


160 


71-3 


116. 9 


101.7 


210 


94.0 


154-I 


134-1 


161 


71.8 


117. 6 


102.3 


211 


94-4 


154.8 


134-7 


162 


72-3 


118. 4 


103.0 


212 


94-9 


IS5-6 


135-4 


163 


72.7 


119. 1 


103.6 


213 


95-3 


156-3 


136.0 


164 


73-2 


119. 9 


104.3 


214 


95-8 


157-1 


136-7 


165 


73-6 


120.6 


104.9 


215 


96-3 


157-8 


137-3 


166 


74-1 


121. 4 


105.6 


216 


96.7 


158.6 


138.0 


167 


74-5 


122. 1 


106.2 


217 


97-2 


159-3 


138.6 


168 


74-9 


122.9 


106.9 


218 


97-6 


160. 


139-3 


169 


75-4 


123.6 


107-5 


219 


98.1 


160.8 


139-9 


170 


75-8 


124.4 


108.2 


220 


98.6 


161.5 


140.6 


171 


76-3 


125. 1 


108.8 


211 


99.0 


162.3 


141. 2 


172 


76.8 


125.8 


109-5 


222 


99-5 


163.0 


141. 9 


173 


77-3 


126.6 


no. I 


223 


99-9 


163-7 


142.5 


174 


77-7 


127.3 


110.8 


224 


100.4 


164.5 


143-2 


175 


78.2 


128. 1 


III. 4 


225 


100.9 


165.3 


143.8 


176 


78.6 


128.8 


112.0 


226 


101.3 


166.0 


144. 5 


177 


^9.1 


129.5 


112.6 


227 


101.8 


166.8 


145-1 


178 


79-5 


130-3 


^^3-3 


228 


102.2 


167.5 


145.8 


179 


80.0 


131. 


"3-9 


229 


102.7 


168.3 


146.4 



SUGAR AND SACCHARINE PRODUCTS. 



621 



DEFREN'S TABLE FOR THE DETERMINATION OF DEXTROSE, MALTOSE, 

AND -LACTOSE—iConcli'ded). 



Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


Milligrams 

of Cupric 

Oxide. 


Milligrams 


Milligrams 


Milligrams 


of Dextrose. 


of Maltose. 


of Lactose. 


of Dextrose. 


of Maltose. 


of Lactose. 


230 


103. 1 


169. 1 


147-P 


280 


126.1 


206.8 


179.6 


231 


103.6 


169.8 


147-7 


281 


126.5 


207.5 


180.2 


232 


104.0 


170.6 


148.3 


282 


127.0 


208.3 


180.9 


233 


104 -5 


171-3 


149-0 


283 


127.4 


209.0 


181.5 


234 


105.0 


172. 1 


149.6 


284 


127.9 


209.8 


182.2 


235 


105.4 


172.8 


150-3 


285 


128.3 


210.5 


182.9 


236 


105.9 


173-6 


.150-9 


286 


128.8 


211. 3 


183.6 


237 


106.3 


174-3 


151. 6 


287 


129.3 


212. 1 


184.2 


238 


106.8 


175-I 


152.2 


288 


129.7 


212.8 


184.9 


239 


107.2 


175-8 


152-9 


289 


130.2 


213.6 


185.6 


240 


107.7 


176.6 


153-5 


290 


130.6 


214-3 


186.2 


241 


108. 1 


177-3 


154-2 


291 


131.1 


215.1 


186.9 


242 


108.6 


178. 1 


154.8 


292 


13I-5 


215-9 


187.6 


243 


109.0 


178.8 


155-5 


293 


132.0 


216.6 


188.2 


244 


109.5 


179.6 


156.1 


294 


132-5 


217.4 


188.9 


245 


109.9 


180.3 


156.8 


295 


133-0 


218.2 


189.5 


246 


no. 4 


181. 1 


157-4 


296 


133.4 


218.9 


190.2 


247 


no. 9 


i8r.8 


158.1 


297 


133-9 


219.7 


190.8 


248 


III. 3 


182.6 


158-7 


298 


134-3 


220.4 


191-5 


249 


III. 8 


183-3 


159-4 


299 


134-8 


221.2 


192.1 


250 


112. 3 


184. 1 


160.0 


300 


135-3 


221.9 


192.8 


251 


112. 7 


184.8 


160.7 


301 


135-7 


222.7 


193.4 


252 


113. 2 


185-5 


161. 3 


302 


136.2 


223-5 


194.1 


253 


"3-7 


186.3 


162.0 


303 


136.6 


224.2 


194.7 


254 


114. 1 


187. 1 


162.6 


304 


137-1 


225.0 


195.3 


255 


114. 6 


187.8 


163-3 


305 


137.6 


225.8 


196.0 


256 


115. 


188.6 


163.9 


306 


138.0 


226.5 


196.6 


257 


115-5 


189.3 


164.6 


307 


138-5 


227.3 


197-3 


358 


116. 


190. 1 


165.2 


308 


138.9 


228.1 


197.9 


259 


116. 4 


190.8 


165.9 


309 


139-4 


228.8 


198.6 


260 


116. 9 


191. 6 


166.5 


310 


139-9 


229.6 


199-3 


261 


"7-3 


192.4 


167.2 


3" 


140.3 


230.4 


199.9 


262 


117. 8 


193 -I 


167.8 


312 


140.8 


231.1 


200.6 


263 


118. 3 


193-9 


168.1 


313 


141.2 


231.9 


201.3 


264 


118. 7 


194.6 


169.5 


314 


141.7 


232.7 


202.0 


265 


119. 2 


195-4 


169.8 


315 


142.2 


233.4 


202.6 


266 


119. 6 


196. 1 


170.4 


316 


142.6 


234.2 


203-3 


267 


120. 1 


196.9 


171.1 


317 


143 -I 


234.9 


203.0 


268 


120.6 


197.7 


171.7 


318 


143.6 


235-7 


204.6 


269 


121. 


198.4 


172.4 


319 


144.0 


236.5 


205.3 


270 


121. 4 


199.2 


173-0 


320 


144-5 


237.2 


205.9 


271 


121. 9 


199.9 


173-7 










272 


122.4 


200.7 


174.4 










273 


122.8 


201.5 


I75-0 










274 


125.3 


202.2 


175-7 










27s 


123-7 


203.0 


176.3 










376 


124.2 


203.7 


177.0 










277 


124.6 


204.5 


177.6 










278 


125. 1 


205 . 2 


178.3 










279 


12^.6 


206.0 


T78.0 











622 FOOD INSPECTION AND ANALYSIS. 

Munson and Walker Method.* — i. Preparation of Solutions and 
Asbestos. — Use the copper sulphate solution and alkaline tartrate solution 
as given on page 615. Prepare the asbestos, which should be the 
amphibole variety, by first digesting with i :3 hydrochloric acid for t\A o or 
three days. Wash free from acid, and digest for a similar period with 
soda solution, after which treat for a few hours with hot alkaline copper 
tartrate solution of the strength employed in sugar determinations. Then 
wash the asbestos free from alkali, finally digest with nitric acid for several 
hours, and after washing free from acid, shake with water for use. In 
preparing the Gooch crucible, load it with a film of asbestos one-fourth inch 
thick, wash this thoroughly with water to remove fine particles of asbestos; 
finally wash with alcohol and ether, dry for thirty minutes at 100° C, 
cool in a desiccator and weigh. It is best to dissolve the cuprous oxide 
with nitric acid each time after weighing, and use the same felts over and 
over again, as they improve with use. 

2. Process. — Transfer 25 cc. each of the copper and alkaline tartrate 
solutions to a 400-cc. Jena or Non-sol beaker, and add 50 cc. of reducing 
sugar solution, or, if a smaller volume of sugar solution be used, add 
water to make the final volume 100 cc. Heat the beaker upon an asbestos 
gauze over a Bunsen burner, so regulate the flame that boiling begins in 
four minutes, and continue the boiling for exactly two minutes. Keep 
the beaker covered with a watch-glass throughout the entire time of 
heating. Without diluting, filter the cuprous oxide at once on an asbestos 
felt in a porcelain Gooch crucible, using suction. Wash the cuprous 
oxide thoroughly with water at a temperature of about 60° C., then with 
10 cc. of alcohol, and finally with 10 cc. of ether. Dry for thirty minutes 
in a water oven at 100° C., cool in a desiccator and weigh as cuprous 
oxide. 

The number of milligrams of copper reduced by a given amount of 
reducing sugar differs when sucrose is present and when it is absent. 
In the tables on pages 623 to 631 the absence of sucrose is assumed, except 
in the two columns under invert sugar, where one for mixtures of invert 
sugar and sucrose (0.4 gram of total sugar in 50 cc. of solution), and one 
for invert sugar and sucrose when the 50 cc. of solution contains 2 grams 
of total sugar are given, in addition to the column for invert sugar 
alone. 



* Jour. Am. Chem. Soc, 28, 1906, p. 163; 29, 1907, p. 541; U. S. Dept. Agric, Bur. 
of Chem., Bui. 107 (rev.), p. 241; Circ. 82. 



SUGAR AND SACCHARINE PRODUCTS. 



623 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 
SUGAR, LACTOSE, AND MALTOSE. 











[Weights in 


milligrams.] 


















Invert Sugar 














o 








and Sucrose. 




Lactose. 




Maltose. 





3 
















3 


o 


























(U 

•o 
O 


'a 




^ 










X 

+ 


d 

X 

+ 




d 

X 

+ 




3 

s 

a 

3 


u 

<u 
a 
0. 




2 

V 

Q 


(U 

> 


d 





X 


i 

X 
6 


6 
6 


6 

Si 

X 
6 


d 




1 

a 



• 10 


8.9 


4.0 


4.5 


1.6 




3.8 


3.9 


4.0 


5.9 


6.2 


10 


II 


9.8 


4.5 


S-o 


2 . 1 




4.S 


4.6 


4-7 


6.7 


7.0 


II 


13 


10.7 


4.9 


5-4 


2.5 




5.1 


5.3 


5.4 


7.5 


7.9 


12 


13 


ii-S 


5.3 


5.8 


3.0 




5.8 


5.9 


6.1 


8.3 


8.7 


13 


14 


12.4 


5.7 


6.3 


3.4 




6.4 


6.6 


6.8 


9.1 


95 


14 


IS 


13-3 


6.2 


6.7 


3.9 




7-1 


7.3 


7.S 


9.9 


10. 4 


IS 


i6 


14-2 


6.6 


7.2 


4.3 




7.8 


8.0 


8.2 


10.6 


II. 2 


16 


17 


IS-I 


7.0 


7.6 


4.8 




8.4 


8.6 


8.9 


II. 4 


12 .0 


17 


i8 


16 .0 


7.5 


8.1 


5-2 




9.1 


9.3 


9-5 


12 . 2 


12.9 


18 


19 


16.9 


7.9 


8.5 


5.7 




9.7 


10. 


10.2 


13.0 


13.7 


19 


ao 


17.8 


8.3 


8.9 


6.1 




10.4 


10.7 


10.9 


13.8 


14.6 


20 


31 


18.7 


8.7 


9.4 


6.6 




n.o 


II. 3 


II. 6 


14.6 


15.4 


21 


32 


I9S 


9.2 


9.8 


7.0 




II. 7 


12.0 


12.3 


15.4 


16. 2 


32 


23 


20 . 4 


9.6 


10.3 


7.5 




12.3 


12.7 


13.0 


16.2 


17.1 


23 


24 


21.3 


10. 


10.7 


7.9 




13.0 


13.4 


13.7 


17.0 


17.9 


24 


as 


22 . 2 


10, s 


1 1 . 2 


8.4 




13.7 


14.0 


14.4 


17.8 


18.7 


25 


a6 


23.1 


10. 9 


II .6 


8.8 




14.3 


14.7 


IS. I 


18.6 


19.6 


26 


27 


24 . 


11-3 


12.0 


9.3 




15.0 


15.4 


15.8 


19.4 


20 . 4 


27 


28 


24.9 


II. 8 


12.5 


9-7 




15.6 


16. I 


16. s 


20. 2 


21.2 


28 


29 


25. 8 


12.2 


12.9 


10 . 2 




16.3 


16.7 


17. 1 


21.0 


22 . 1 


29 


30 


26.6 


12.6 


13.4 


10.7 


4.3 


16.9 


17.4 


17.8 


21.8 


32.9 


30 


31 


27.5 


13.1 


13.8 


1 1 . I 


4.7 


17.6 


18. I 


18. s 


22.6 


23-7 


31 


32 


28.4 


13.5 


14.3 


II. 6 


5.2 


18.3 


18.7 


19.2 


23.3 


24. 6 


32 


33 


293 


13.9 


14.7 


12 .0 


5.6 


18.9 


19.4 


19.9 


24.1 


25.4 


33 


34 


30.2 


14.3 


IS. 2 


12. s 


6.1 


19.6 


20. I 


20.6 


24.9 


26. 2 


34 


35 


311 


14.8 


15.6 


12.9 


6.5 


20.2 


20.8 


21.3 


25.7 


27. 1 


35 


36 


32.0 


15-2 


16. 1 


13.4 


7.0 


20.9 


21.4 


22.0 


26. s 


27.9 


36 


37 


32.9 


15.6 


16. s 


13.8 


7.4 


21.5 


22. I 


22.7 


27-3 


28.7 


37 


38 


33-8 


16. I 


16.9 


14.3 


7.9 


22.2 


22.8 


23.4 


28.1 


29.6 


38 


39 


34-6 


16. s 


17.4 


14.7 


8.4 


22.8 


23. 5 


24.1 


28.9 


30.4 


39 


40 


35-5 


16.9 


17.8 


15.2 


8.8 


23.5 


24.1 


24.8 


29.7 


31.3 


40 


41 


36.4 


17.4 


18.3 


15.6 


9.3 


24.2 


24.8 


25.4 


30. 5 


32.1 


41 


42 


37-3 


17.8 


18.7 


16. 1 


9.7 


24.8 


25. S 


26. 1 


31.3 


32.9 


42 


43 


38.2 


18.2 


19. 2 


16.6 


10. 2 


25.5 


26.2 


26.8 


32.1 


33.8 


43 


44 


391 


18.7 


19 .6 


17.0 


10.7 


26. 1 


26.8 


27.5 


32.9 


34.6 


44 


4S 


40.0 


19. 1 


20. 1 


17.5 


II . I 


26.8 


27.5 


28.2 


33.7 


35-4 


45 


46 


40.9 


19.6 


20. s 


17.9 


II. 6 


27.4 


28.2 


28.9 


34.4 


36.3 


46 


47 


41.7 


20.0 


21.0 


18.4 


12.0 


28.1 


28.9 


29.6 


35.2 


37.1 


47 


48 


42 .6 


20. 4 


21.4 


18.8 


12. S 


28.7 


29.5 


30.3 


36.0 


37.9 


48 


49 


43-5 


20.9 


21.9 


19-3 


12.9 


29.4 


30.2 


31.0 


36.8 


38.8 


49 


SO 


44-4 


21.3 


22.3 • 


19.7 


13.4 


30.1 


30.9 


31.7 


37-6 


39.6 


SO 


SI 


45-3 


21 .7 


22.8 


20. 2 


13.9 


30.7 


31.5 


32.4 


38.4 


40.4 


51 


S2 


46. 2 


22 . 2 


23.2 


20. 7 


14.3 


31.4 


32.2 


33.0 


39.2 


41.3 


52 


S3 


47-1 


22.6 


23.7 


21 . 1 


14.8 


32.1 


32.9 


33.7 


40.0 


42. I 


53 


54 


48.0 


23.0 


24.1 


21.6 


15.2 


32.7 


33.6 


34-4 


40.8 


42.9 


54 


55 


48.9 


23. 5 


24.6 


22 .0 


15.7 


33.4 


34-3 


35-1 


41 .6 


43.8 


55 


56 


49-7 


23.9 


25.0 


22. s 


16.2 


34.0 


34.9 


35.8 


42.4 


44.6 


S6 


57 


SO. 6 


24.3 


25.5 


22.9 


16.6 


34.7 


35.6 


36.5 


43.2 


45.4 


57 


58 


51-5 


24.8 


25-9 


23.4 


17. 1 


35.4 


36.3 


37.2 


44.0 


46.3 


58 


59 


52.4 


25.2 


26.4 


23.9 


17.5 


36.0 


37.0 


37.9 


44.8 


47.1 


59 


60 


53-3 


25 .6 


26.8 


243 


18.0 


36.7 


37.6 


38.6 


45.6 


48.0 


60 


61 
62 
63 


54.2 


26.1 


27.3 


24.8 


18. 5 


37.3 


38.3 


39.3 


46.3 


48.8 


61 


55-1 


26. 5 


27.7 


25.2 


18.9 


38.0 


39.0 


40.0 


47-1 


49-6 


62 


56.0 


27.0 


28.2 


25-7 


19.4 


38.6 


39.7 


40.7 


47.9 


50.5 


63 


64 


56.8 


27.4 


28.6 


26.2 


19.8 


39.3 


40.3 


41.4 


48.7 


51.3 


64 



624 



FOOD INSPECTION AND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, 
SUGAR, LACTOSE, AND MALTOSE— (Continued). 
[Weights in milligrams.] 



INVERT 



o 
3 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


d 
















5I 


O 

0) 


a' 



d 


u 

eo 

3 

tn 





— 1- 




d 
X 

+ 


d 

+ 




d 

X 

+ 




V 

•0 
■>< 



3 

i 

3 
O 


w. 


S 




2 S, 


GS, 





6 


d 


d 


d 


3 






4-> 

Q 




0^ 

6 




6 


!3 


S3 

X 


X 
6 


?! 


s 

a 
3 



6S 


57-7 


27.8 


29. 1 


26.6 


20.3 


40.0 


41.0 


42.1 


49.5 


52.1 


6S 


66 


S8.6 


28.3 


29s 


27.1 


20.8 


40.6 


41.7 


42.8 


50.3 


S3.0 


66 


67 


59. S 


28.7 


30.0 


27-5 


21.2 


41.3 


42.4 


43-5 


51. 1 


S3. 8 


67 


68 


60. 4 


29. 2 


30.4 


28.0 


21.7 


41.9 


43.1 


44.2 


51.9 


54.6 


68 


69 


61.3 


29.6 


30.9 


28. 5 


22 .2 


42.6 


43.7 


44-8 


52-7 


S5.5 


69 


70 


62.2 


30.0 


313 


28.9 


22 .6 


43.3 


44.4 


45. 5 


S3. 5 


56.3 


70 


71 


63.1 


30.5 


31.8 


29.4 


231 


43.9 


45. 1 


46.2 


54. 3 


57. I 


71 


72 


64.0 


30.9 


32.3 


29.8 


23-5 


44.6 


45.8 


46.9 


55.1 


58.0 


72 


73 


64.8 


314 


32.7 


30.3 


24.0 


45. 2 


46.4 


47.6 


55. 9 


S8.8 


73 


74 


6S-7 


31.8 


33-2 


30.8 


24.5 


45. 9 


47.1 


48.3 


56.7 


59.6 


74 


7S 


66.6 


32.2 


33.6 


31-2 


24.9 


46.6 


47.8 


49.0 


57. 5 


60. 5 


75 


76 


67. S 


32.7 


34-1 


31.7 


25-4 


47.2 


48.5 


49.7 


58.2 


61.3 


76 


77 


68.4 


33 -^ 


345 


321 


25.9 


47.9 


49.1 


SO. 4 


59.0 


62.1 


77 


78 


69 -3 


33-6 


350 


32.6 


26.3 


48. 5 


49.8 


51. 1 


59.8 


63.0 


78 


79 


70.2 


34-0 


35.4 


33-1 


26.8 


49.2 


SO. 5 


51.8 


60.6 


63.8 


79 


80 


71. 1 


34-4 


35-9 


33 5 


27-3 


49.9 


51.2 


52. S 


61 .4 


64.6 


80 


81 


71.9 


34.9 


36.3 


34.0 


27.7 


SO. 5 


SI. 9 


53.2 


62.2 


6S.5 


81 


82 


72.8 


35-3 


36.8 


34-5 


28.2 


SI.2 


52. S 


53.9 


63.0 


66.3 


82 


83 


73-7 


35-8 


37-3 


34-9 


28.6 


SI. 8 


53.2 


54.6 


63.8 


67.1 


83 


84 


74.6 


36.2 


37-7 


35-4 


29.1 


S2.5 


S3. 9 


553 


64.6 


68.0 


84 


8S 


75-5 


36.7 


38.2 


35-8 


29.6 


S3. 1 


54.6 


56.0 


65.4 


68.8 


85 


86 


76.4 


37-1 


38.6 


36.3 


30.0 


S3. 8 


55.2 


S6.6 


66.2 


69.7 


86 


87 


77-3 


37-5 


39-1 


36.8 


30. 5 


54-5 


55.9 


S7.3 


67 .0 


70.5 


87 


88 


78.2 


38.0 


39-5 


37-2 


310 


SS. I 


S6.6 


S8.o 


67.8 


71.3 


88 


89 


79.1 


38.4 


40.0 


37-7 


31-4 


55.8 


57.3 


58. 7 


68.5 


72.2 


89 


90 


79-9 


38.9 


40.4 


38.2 


319 


S6.4 


58.0 


59.4 


69.3 


73.0 


90 


91 


80.8 


39.3 


40.9 


38.6 


32.4 


57.1 


58.6 


60. 1 


70.1 


73.8 


91 


92 


81.7 


39-8 


41.4 


39-1 


32.8 


57.8 


59-3 


60.8 


70.9 


74-7 


92 


93 


82.6 


40.2 


41.8 


39.6 


33.3 


S8.4 


60.0 


61. S 


71.7 


75.5 


93 


94 


83. S 


40.6 


42.3 


40.0 


33.8 


59. I 


60.7 


62.2 


72. 5 


76.3 


94 


9S 


84.4 


41. 1 


42.7 


40.5 


34.2 


59.7 


61.3 


62.9 


73.3 


77.2 


95 


96 


85.3 


41. 5 


43.2 


41 .0 


34-7 


60.4 


62.0 


63.6 


74.1 


78.0 


96 


97 


86.2 


42 .0 


43.7 


41 .4 


35-2 


61. I 


62.7 


64.3 


74.9 


78.8 


97 


98 


87.1 


42.4 


44.1 


41.9 


35.6 


61.7 


63.4 


65.0 


75. 7 


79.7 


98 


99 


87.9 


42 .9 


44.6 


42.3 


36.1 


62.4 


64.0 


65.-' 


76. 5 


80. s 


99 


100 


88.8 


43-3 


4SO 


42.8 


36.6 


63.0 


64.7 


66.4 


77.3 


81.3 


100 


101 


89.7 


43-8 


45.5 


43-3 


37.0 


63.7 


65.4 


67.1 


78.1 


82.2 


lOI 


102 


90.6 


44.2 


46.0 


43.8 


37. S 


64.4 


66.1 


67.8 


78.8 


83.0 


102 


103 


91. S 


44.7 


46.4 


44.2 


38.0 


65.0 


66.7 


68. s 


79.6 


83.8 


103 


104 


92.4 


45-1 


46.9 


44.7 


38.5 


65.7 


67.4 


69.1 


80.4 


84.7 


104 


los 


93-3 


45-5 


47.3 


45-2 


38.9 


66.4 


68.1 


69.8 


81.2 


85.5 


105 


106 


94.2 


46 . 


47-8 


45-6 


39.4 


67.0 


68.8 


70.5 


82.0 


86.3 


106 


107 


9.S.O 


46.4 


48.3 


46. I 


39-9 


67.7 


69.5 


71.2 


82.8 


87.2 


107 


108 


9S-9 


46.9 


48.7 


46.6 


40.3 


68.3 


70. I 


71.9 


83.6 


88.0 


108 


109 


96.8 


47-3 


49.2 


47.0 


40.8 


69.0 


70.8 


72.6 


84.4 


88.8 


1 09 


no 


97-7 


47.8 


49-6 


47.5 


41.3 


69.7 


71.5 


73.3 


85.2 


89.7 


no 


III 


98.6 


48.2 


SO. I 


48.0 


41.7 


70.3 


72.2 


74.0 


86.0 


90.5 


III 


112 


99-5 


48.7 


SO. 6 


48.4 


42.2 


71 .0 


72.8 


74.7 


86.8 


91.3 


112 


113 


100. 4 


49-1 


5I.O 


48.9 


42.7 


71.6 


73. 5 


734 


87.6 


92.2 


113 


114 


101.3 


49.6 


51-5 


49-4 


43.2 


72.3 


74.2 


76.1 


88.4 


93.0 


114 


"5 


102 . 2 


50.0 


SI. 9 


49.8 


43.6 


73.0 


74.9 


76.8 


89.2 


93.9 


IIS 


116 


103.0 


SO. 5 


52.4 


50.3 


44.1 


73.6 


75.6 


77-5 


90.0 


94.7 


116 


H7 


103.9 


50.9 


52.9 


SO. 8 


44.6 


74.3 


76.2 


78.2 


90.7 


95.5 


117 


118 


104.8 


51.4 


53-3 


51.2 


45.0 


75-0 


76.9 


78.9 


91-5 


96.4 


118 


119 


105.7 


SI.8 


53.8 


SI. 7 


45. S 


75.6 


77.6 


79.6 


92.3 


97.2 


119 



SUGAR AND SACCHARINE PRODUCTS. 



625 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
















3 


o 







































Q 










a 








"rt 


^^ 











d 


u 


O 


'3 



u 


n! 

3 
C/3 




2 




X 

+ 


X 
+ 




•f 


V} 


3 


i-i 







=5 rt 


6 ? 


6 


d 


6 


d 


d 


fl 





(U 


ij 


Ih 


0^ 


rt 5? 


a 


n 


a 


Si 


13 


p 


u 

P. 
3 


0. 
a 



0) 


> 


C 3 
0^ 


K 


X 
2 


ffi 


X 


X 


Ih 

a 

3 


O 





Q 




6 


" 


CJ 








C 


6 





I20 


106.6 


52.3 


54.3 


52.2 


46.0 


76.3 


78.3 


80.3 


93 I 


98.0 


120 


121 


107.5 


52.7 


54-7 


52.7 


46.5 


76.9 


79.0 


81.0 


93-9 


98.9 


121 


122 


108.4 


53-2 


55-2 


S3 -I 


46.9 


77.6 


79.6 


81.7 


94-7 


99-7 


123 


123 


109.3 


53-6 


SS-7 


53.6 


47.4 


78.3 


80.3 


82.4 


95-5 


TOO. 5 


123 


124 


no. I 


S4-I 


S6.i 


54-1 


47-9 


78.9 


81.0 


83.1 


96.3 


lOI . 4 


124 


I2S 


I II .0 


54-5 


56.6 


54-5 


48.3 


79-6 


81.7 


83.8 


97 I 


102 . 2 


12s 


126 


1 1 1 .9 


55-0 


57-0 


SS-o 


48.8 


80.3 


82.4 


84-s 


97-9 


103.0 


126 


127 


112. 8 


55-4 


57-5 


SS-S 


49-3 


80.9 


83.0 


8s. 2 


98.7 


103.9 


127 


128 


II3-7 


55-9 


58.0 


SS-9 


49.8 


81.6 


83-7 


8S.9 


99-4 


104.7 


128 


12 9 


114. 6 


56.3 


58.4 


56.4 


50.2 


82.2 


84-4 


86.6 


lOO. 2 


I05-S 


129 


130 


iiS-S 


56.8 


58.9 


56.9 


SO-7 


82.9 


8S.1 


87.3 


lOI .0 


106.4 


130 


131 


116.4 


57-2 


59-4 


57-4 


51-2 


83.6 


85.7 


88.0 


IOI.8 


107 . 2 


131 


132 


117. 3 


57-7 


59-8 


S7-8 


51-7 


84.2 


86.4 


88.7 


102 .6 


108.0 


132 


133 


118. I 


58.1 


60.3 


58-3 


S2-I 


84.9 


87.1 


89.4 


103 -4 


108.9 


133 


134 


1190 


S8.6 


60.8 


S8.8 


52-6 


85.5 


87.8 


90. 1 


104.2 


109-7 


134 


13s 


119. 9 


59-0 


61.2 


59-3 


S3-I 


86.2 


88.5 


90.8 


105.0 


no. 5 


135 


136 


120.8 


59-5 


61.7 


59-7 


53-6 


86.9 


89- I 


91.5 


105.8 


III .4 


136 


137 


121 . 7 


60.0 


62.2 


60. 2 


54-0 


87-S 


89.8 


92.1 


106 .6 


112 . 2 


137 


138 


122 .6 


60.4 


62.6 


60. 7 


54-5 


88.2 


90. S 


92.8 


107.4 


113 -0 


138 


139 


123-5 


60.9 


63.1 


61 . 2 


55-0 


88.9 


91.2 


93 5 


108.2 


113-9 


139 


140 


124-4 


61.3 


63.6 


61.6 


SS-S 


89. S 


91.9 


94-2 


109.0 


114-7 


140 


141 


125.2 


61.8 


64.0 


62.1 


55-9 


90. 2 


92. 5 


94-9 


109. 8 


115-5 


141 


142 


126. 1 


62.2 


64. 5 


62.6 


56-4 


90.8 


93-2 


95-6 


110.5 


1 16. 4 


142 


143 


127.0 


62.7 


65-0 


63.1 


56-9 


9I-S 


93.9 


96.3 


III. 3 


117. 2 


143 


144 


127.9 


63.1 


65-4 


63-5 


57-4 


92.2 


94-6 


97.0 


112 . 1 


118. 


144 


145 


128.8 


63-6 


65-9 


64.0 


S7-8 


92.8 


95-3 


97.7 


112 .9 


118.9 


I4S 


146 


129.7 


64.0 


66.4 


64-5 


s8-3 


93 S 


95-9 


98.4 


113-7 


119-7 


146 


147 


130.6 


64. 5 


66.9 


65.0 


58.8 


94-2 


96.6 


99.1 


114-S 


120. 5 


147 


148 


131-5 


65.0 


67-3 


65-4 


59-3 


94-8 


97-3 


99.8 


115-3 


121 .4 


148 


149 


132.4 


65-4 


67.8 


6s-9 


59-7 


95-5 


98.0 


100. s 


116. 1 


122 . 2 


149 


ISO 


133-2 


65-9 


68.3 


66.4 


60.2 


96. 1 


98.7 


I0I.2 


116. 9 


123.0 


150 


ISI 


134-1 


66.3 


68.7 


66.9 


60.7 


96.8 


99.3 


101.9 


117-7 


123-9 


151 


152 


I3S-0 


66.8 


69. 2 


67-3 


61 .2 


97.5 


100. 


102.6 


118. 5 


124-7 


152 


153 


135-9 


67.2 


69-7 


67.8 


61.7 


98.1 


100.7 


103.3 


119-3 


125-5 


153 


154 


136.8 


67.7 


70.1 


68.3 


62.1 


98.8 


IOI.4 


104.0 


120.0 


126. 4 


154 


ISS 


137-7 


68.2 


70.6 


68.8 


62.6 


99-5 


102 . I 


104.7 


120.8 


127.2 


15s 


156 


138.6 


68.6 


71-1 


69 . 2 


63-1 


100. I 


102.8 


105.4 


121 .6 


128.0 


156 


157 


139-5 


69. 1 


71.6 


69.7 


63-6 


100.8 


103-4 


106. I 


122.4 


128.9 


157 


158 


140.3 


69-5 


72.0 


70.2 


64. 1 


lOi.S 


104. 1 


106.8 


123.2 


129-7 


158 


IS9 


141 . 2 


70.0 


72. S 


70.7 


64-S 


102. 1 


104.8 


107. 5 


124.0 


130. 5 


159 


160 


142 . 1 


70.4 


73-0 


71.2 


65.0 


102.8 


105.5 


108.2 


124.8 


131-4 


160 


161 


143-0 


70.9 


73-4 


71.6 


65-5 


103-4 


106.2 


108.9 


125.6 


132.2 


i6r 


162 


143-9 


71.4 


73-9 


72.1 


66.0 


104. I 


106.8 


109.6 


126. 4 


133-0 


162 


163 


144-8 


71.8 


74-4 


72.6 


66.5 


104.8 


107. 5 


no. 3 


127.2 


133-9 


163 


164 


145-7 


72.3 


74-9 


73-1 


66.9 


105 -4 


108.2 


III.O 


128.0 


134-7 


164 


i6s 


146.6 


72.8 


75-3 


73-6 


67.4 


106. 1 


108.9 


III. 7 


128.8 


I3S-S 


i6s 


166 


147-5 


73-2 


75-8 


74.0 


67-9 


106.8 


109.6 


112. 4 


129.6 


136-4 


166 


167 


148.3 


73-7 


76.3 


74-S 


68.4 


107.4 


no. 3 


113. 1 


130.3 


137-2 


167 


168 


149.2 


74-1 


76.8 


7S-0 


68.9 


108. i 


no. 9 


1138 


1311 


13G-0 


168 


169 


150.1 


74.6 


77.2 


75-5 


69 -3 


108.8 


III. 6 


114-5 


131. 9 


138.9 


169 


170 


151 -0 


75-1 


77-7 


76.0 


69.8 


109.4 


112. 3 


IIS-2 


132.7 


139-7 


170 


171 


151-9 


75-5 


78.2 


76.4 


70.3 


no. I 


113. 


llS-9 


133-5 


140-5 


171 


172 


152.8 


76.0 


78.7 


76.9 


70.8 


no. 8 


113. 7 


116. 6 


134.3 


141-4 


17a 


173 


153-7 


76.4 


79 I 


77.4 


71-3 


III. 4 


114-3 


117. 3 


I3S-I 


142 . 2 


^73 


174 


154.6 


76.9 


79-6 


77-9 


71.7 


112. 1 


nS.o 


118. 


135-9 


143-0 


174 



626 



FOOD INSPECTION AND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 


5 


3 
















3 










"(3 






d 


d 




d 




V 


3 


"5 











is 


4-) 

B t5 


6 


+ 
6 


X 

+ 
d 


q 


+ 
d 


•a 


3 


O 


<u 




u 


, h '^o 


a <^ 


?! 


s 


?j 




a 


p 


a 

3 


a 
a 



(a 


> 

f2 




E 3 


w 


W 


K 


1 


K 


a 

3 


o 





Q 




d 


« 


6 


6 





u 


d 





175 


IS5-5 


77-4 


80.1 


78.4 


72.2 


112. 8 


IIS. 7 


118. 7 


136.7 


143-9 


175 


176 


1S6.3 


77-8 


80.6 


78.8 


72.7 


113. 4 


116. 4 


119.4 


137.5 


144.7 


176 


177 


IS7-2 


78.3 


81.0 


79-3 


73-2 


114. 1 


117. 1 


120. 1 


138.3 


I4S-S 


177 


178 


158. I 


78.8 


81.5 


79-8 


73-7 


114. 8 


117. 8 


120.8 


I39-I 


146.4 


178 


179 


IS9-0 


79-2 


82.0 


80.3 


74-2 


IIS. 4 


118. 4 


121. S 


139-8 


147.2 


179 


180 


IS9-9 


79-7 


82.5 


80.8 


74.6 


116. 1 


119. 1 


122.2 


140.6 


148.0 


180 


i8i 


160.8 


80.1 


82.9 


81.3 


75-1 


116.7 


119. 8 


122 .9 


I4I-4 


148.9 


181 


182 


161 . 7 


80.6 


83-4 


81.7 


75-6 


117. 4 


120. s 


123.6 


142 .2 


149-7 


182 


183 


162.6 


81. 1 


83.9 


82.2 


76.1 


118. 1 


121 . 2 


124.3 


143-0 


150.5 


183 


184 


163.4 


81.5 


84-4 


82.; 


76.6 


118. 7 


121. 8 


125.0 


143-8 


151-4 


184 


i8s 


164.3 


82.0 


84-9 


83.2 


77-1 


119. 4 


122. s 


125-7 


144.6 


152.2 


185 


186 


165.2 


82.5 


8S-3 


83-7 


77.6 


120. 1 


123 . 2 


126.4 


145-4 


IS3-0 


186 


187 


166. 1 


82.9 


85.8 


84.2 


78.0 


120.7 


123.9 


127.1 


146. 2 


153-9 


187 


188 


167 .0 


83-4 


86.3 


84.6 


78.5 


121. 4 


124. 6 


127.8 


147-0 


154-7 


188 


189 


167.9 


83-9 


86.8 


85.1 


79-0 


122. 1 


125. 3 


128.5 


147-8 


155-5 


189 


190 


168.8 


84.3 


87.2 


85.6 


79-5 


122.7 


125.9 


129.2 


148.6 


156.4 


190 


191 


169. 7 


84.8 


87-7 


86.1 


80.0 


123.4 


126.6 


129.9 


149-3 


157-2 


191 


192 


170. S 


85-3 


88.2 


86.6 


80.5 


124. I 


127.3 


130.6 


150. I 


158.0 


192 


193 


171-4 


85-7 


88.7 


87.1 


81.0 


124.7 


128.0 


131.3 


150.9 


158.9 


193 


194 


172.3 


86.2 


89.2 


87.6 


81.4 


125.4 


128.7 


132.0 


151-7 


159-7 


194 


19s 


1732 


86.7 


89.6 


88.0 


81.9 


126. 1 


129.4 


132.7 


152.5 


160.5 


195 


196 


174. I 


87.1 


90 . 1 


88.5 


82.4 


126. 7 


130.0 


133.4 


153-3 


161 . 4 


196 


197 


175.0 


87.6 


90.6 


89.0 


82.9 


127.4 


130.7 


134-1 


154-1 


162 . 2 


197 


198 


175-9 


88.1 


91. 1 


89 -5 


83-4 


128. I 


131.4 


134-8 


154.9 


163 .0 


198 


199 


176.8 


88.5 


91.6 


90.0 


83 -9 


128.7 


132. I 


I35S 


155-7 


163.9 


199 


200 


177-7 


89.0 


92 .0 


90.5 


84-4 


129.4 


132.8 


136.2 


156.5 


164.7 


200 


201 


178. 5 


89.5 


92.5 


91 .0 


84.8 


130.0 


133. 5 


136.9 


IS7-3 


165.5 


201 


202 


179-4 


89.9 


93-0 


91.4 


85-3 


130.7 


134- I 


137.6 


158. I 


166. 4 


202 


203 


180.3 


90.4 


93-5 


91.9 


85-8 


131. 4 


134-8 


138.3 


158.8 


167 . 2 


203 


204 


181. 2 


90.9 


94.0 


92.4 


86.3 


132.0 


I3S-S 


139.0 


159-6 


168.0 


204 


20s 


182. 1 


91.4 


94-5 


92.9 


86.8 


132.7 


136.2 


139.7 


160.4 


168.9 


205 


206 


183.0 


91.8 


94-9 


93-4 


87.3 


133.4 


136.9 


140.4 


161 . 2 


169.7 


206 


207 


183.9 


92-3 


95-4 


93-9 


87.8 


1340 


137.6 


141. I 


162 .0 


170.5 


207 


208 


184.8 


92.8 


95-9 


94-4 


88.3 


134-7 


138.3 


141. 8 


162.8 


171.4 


208 


209 


185.6 


93-2 


96.4 


94-9 


88.8 


13s -4 


138.9 


142. 5 


163.6 


172.2 


209 


210 


186.5 


93-7 


96.9 


95-4 


89.2 


136.0 


139.6 


143.2 


164.4 


1730 


210 


211 


187.4 


94.2 


97-4 


95-8 


89.7 


136.7 


140.3 


143.9 


165.2 


173-8 


211 


ZI2 


188.3 


94.6 


97-8 


96.3 


90. 2 


137-4 


141 . 


144.6 


166.0 


174-7 


212 


213 


189.2 


95-1 


98.3 


96.8 


90.7 


138.0 


I4I-7 


1453 


166.8 


175-5 


213 


214 


190. 1 


95-6 


98.8 


97-3 


91.2 


138.7 


142.4 


146.0 


167-5 


176.4 


214 


21S 


191 .0 


96 . 1 


99.3 


97-8 


91.7 


139-4 


143 


146.7 


168.3 


177.2 


215 


216 


191 .9 


96.5 


99-8 


98.3 


92 . 2 


140.0 


143-7 


147.4 


169. 1 


178.0 


216 


217 


192.8 


970 


100.3 


98.8 


92.7 


140.7 


144.4 


148.1 


169.9 


178.9 


217 


218 


193-6 


97-5 


100.8 


99-3 


93-2 


14I-4 


145. I 


148.8 


170.7 


179-7 


218 


219 


194-S 


98.0 


lOI .2 


99-8 


93-7 


142.0 


145.8 


149.5 


I7I-5 


180.5 


219 


220 


195-4 


98.4 


lOI . 7 


100 . 3 


94-2 


142.7 


146. 5 


150.2 


172.3 


181.4 


220 


221 


196.3 


98.9 


102 . 2 


100.8 


94-7 


143.4 


147.2 


150.9 


173-I 


182.2 


221 


222 


197.2 


99-4 


102 . 7 


lOI . 2 


95-1 


144.0 


147.8 


15I-6 


173-9 


183.0 


222 


223 


198. I 


99-9 


103.2 


loi . 7 


95-6 


144.7 


148. S 


152.3 


174-7 


183.9 


223 


224 


199.0 


100.3 


103-7 


102 . 2 


96. I 


145.4 


149.2 


153. 


175-5 


184-7 


224 


225 


199 9 


100.8 


104. 2 


102 . 7 


96.6 


146.0 


149.9 


153.7 


176.2 


185. 5 


22s 


226 


200. 7 


loi .3 


104.6 


103.2 


97-1 


146.7 


150.6 


IS4-4 


177.0 


186.4 


226 


227 


201 .6 


101.8 


105. I 


103.7 


97.6 


147.4 


151.3 


iSS-i 


177-8 


187.2 


227 


228 


202 . 5 


102 . 2 


105 . 6 


104 . 2 


98.1 


148.0 


152.0 


ISS.8 


178.6 


188.0 


218 


329 


203.4 


102 . 7 


106. 1 


104.7 


98.6 


148.7 


152.6 


156.5 


179-4 


188.8 


229 



SUGAR AND SACCHARINE PRODUCTS. 



627 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Continued). 

[Weights in milligrams.] 



o 








Invert Sugar 
and Sucrose 


Lactose. 


Maltose. 


q 


3 
















3 


o 







































d 










(U 








H 


__ 






d 




d 


V 


13 

o 


3 



i 


d 












+ 




X 

+ 


•0 



3 


u 







ta 0! 


B "1 


6 


6 





d 


d 


3 





01 






, h '^^ 


rt M 


fj 


5! 




a 


*! 





3 


a 
a 





> 


3 


£ 3 


ffi 


w 


m 


X 


ffi 


a 

3 


o 





Q 
103 . 2 




d 


« 


CJ 


6 


CJ 


u 








■ 230 


204.3 


106.6 


105.2 


99-1 


149.4 


IS3.3 


157.2 


180.2 


189.7 


230 


231 


20s . 2 


103-7 


107 . 1 


ioS-7 


99-6 


150.0 


154.0 


157.9 


181. 


190.5 


231 


232 


206. 1 


104. 1 


107 .6 


106. 2 


100. 1 


150.7 


154.7 


158.6 


181. 8 


191. 3 


232 


233 


207 .0 


104.6 


108. I 


106. 7 


100. 6 


151.4 


155.4 


159.3 


182.6 


192 . 2 


233 


234 


207.9 


los- J 


108.6 


107 . 2 


lOI . 1 


152.0 


156. 1 


160.0 


183.4 


193-0 


234 


235 


208.7 


105 .6 


109. 1 


107.7 


loi .6 


152.7 


156.7 


160.7 


184.2 


193-8 


235 


236 


209. 6 


106 .0 


109.5 


108.2 


102 . 1 


153.4 


157.4 


161 .4 


184.9 


194-7 


236 


237 


210.5 


106.5 


I lO.O 


108.7 


102 .6 


154.0 


158.1 


162. 1 


185.7 


195-5 


237 


238 


21 1 . 4 


107 .0 


iio.s 


109. 2 


103. 1 


154.7 


158.8 


162.8 


186.5 


196.3 


238 


239 


212.3 


I07-S 


I II .0 


109.6 


103-5 


155.4 


159-S 


163. 5 


187.3 


197.2 


239 


240 


213.2 


108.0 


III. 5 


1 10 . I 


104.0 


156. 1 


160.2 


164.3 


188. 1 


198.0 


240 


241 


214. 1 


108.4 


112 .0 


1 10.6 


104.5 


156.7 


160.9 


165.0 


188.9 


1 98. 8 


241 


242 


21 >; .0 


108.9 


112. 5 


III . I 


105.0 


157.4 


161. 5 


165.7 


189.7 


199.7 


242 


243 


215.8 


109.4 


113. 


III . 6 


105-5 


158. 1 


162.2 


166.4 


190.5 


200. 5 


243 


244 


216.7 


109.9 


113. S 


112 . 1 


106.0 


158.7 


162.9 


167 . 1 


191.3 


201.3 


244 


24s 


217.6 


no. 4 


114. 


1 12 . 6 


106. 5 


159.4 


163.6 


167.8 


192. 1 


202 . 2 


245 


246 


218. 5 


no. 8 


114. 5 


113. 1 


107 .0 


160. 1 


164.3 


168. 5 


192.9 


203.0 


246 


247 


219.4 


III. 3 


115.0 


113-6 


107.5 


160.7 


165.0 


169.2 


193-6 


203.8 


247 


248 


220.3 


III. 8 


ilS-4 


114. 1 


108.0 


161 .4 


165-7 


169.9 


19.4.4 


204.7 


248 


249 


221.2 


112. 3 


iiS-9 


114. 6 


108. 5 


162. 1 


166.3 


170.6 


195-2 


205.5 


249 


250 


222.1 


112. 8 


116. 4 


115.1 


109.0 


162.7 


167.0 


171-3 


196.0 


206.3 


250 


251 


223 .0 


113. 2 


116. 9 


115. 6 


109.5 


163.4 


167-7 


172.0 


196.8 


207 . 2 


251 


252 


223.8 


113-7 


117. 4 


116 . 1 


IIO.O 


164. 1 


168.4 


172.7 


197.6 


208.0 


252 


2S3 


224.7 


114. 2 


117. 9 


116. 6 


110.5 


164.7 


169- 1 


173-4 


198.4 


208.8 


253 


2S4 


225.6 


114. 7 


118. 4 


117. 1 


1 1 1 .0 


165.4 


169-8 


174-1 


199.2 


209.7 


254 


25s 


226. 5 


115-2 


118. 9 


117 .6 


III. 5 


166. 1 


170.5 


174-8 


200.0 


210.5 


255 


256 


227.4 


liS-7 


119-4 


118. 1 


112.0 


166.8 


171.1 


175-5 


200. 8 


211.3 


256 


257 


228.3 


116. 1 


119. 9 


118. 6 


112. 5 


167.4 


171.8 


176.2 


201 .6 


212.2 


257 


2S8 


229.2 


116. 6 


120. 4 


119. 1 


113-0 


168. 1 


172.5 


176.9 


202.3 


213.0 


258 


259 


230.1 


117. 1 


120.9 


119. 6 


113-5 


168.8 


173.2 


177.6 


203.1 


213.8 


259 


260 


231 .0 


117 . 6 


121. 4 


120. 1 


114.0 


169.4 


173-9 


178.3 


203.9 


214.7 


260 


261 


231.8 


118. 1 


121 . 9 


120.6 


114.5 


170. 1 


174-6 


179.0 


204.7 


215.5 


261 


262 


232.7 


118. 6 


122 .4 


121 . 1 


115-0 


170.8 


175-3 


179.8 


205.5 


216.3 


262 


263 


2336 


119. 


122.9 


121 .6 


115-S 


171.4 


176.0 


180. 5 


206.3 


217.2 


263 


264 


234-S 


119-S 


123-4 


122 . 1 


116. 


172. 1 


176.6 


181. 2 


207 . 1 


218.0 


264 


265 


235-4 


120 .0 


123-9 


122.6 


116.5 


172.8 


177-3 


181. 9 


207.9 


'218.8 


26s 


266 


236.3 


120. 5 


124.4 


123. 1 


117.0 


173. 5 


178.0 


182.6 


208.7 


219.7 


266 


267 


237.2 


121 .0 


124.9 


123.6 


117-5 


174. I 


178.7 


183.3 


209.5 


220.5 


267 


268 


238.1 


121 . 5 


125-4 


124. 1 


118. 


174-8 


179-4 


184.0 


210.3 


221.3 


268 


269 


238.9 


122 .0 


125-9 


124.6 


118.5 


175.5 


180.1 


184.7 


211 .0 


222 . 1 


269 


270 


239.8 


122 . 5 


126.4 


125. 1 


119.0 


176. 1 


180.8 


185.4 


211. 8 


223.0 


270 


271 


240.7 


122.9 


126.9 


125.6 


119. 5 


176.8 


181. 5 


186. I 


212.6 


223.8 


271 


272 


241 .6 


123-4 


127.4 


126.2 


120.0 


177. 5 


182.1 


186.8 


213.4 


224 .6 


272 


273 


242.5 


123-9 


127.9 


126. 7 


120.6 


178. I 


182.8 


187.5 


214.2 


225.5 


273 


274 


243-4 


124.4 


128.4 


127.2 


121 . 1 


178.8 


183. 5 


188.2 


215.0 


226.3 


274 


275 


244-3 


124.9 


128.9 


127.7 


121 .6 


179.5 


184.2 


188.9 


215.8 


227.1 


27S 


276 


245.2 


125.4 


129.4 


128.2 


122 . 1 


180.2 


184.9 


189.6 


2^6.6 


228.0 


276 


277 


2,46. I 


125-9 


129.9 


128.7 


122.6 


180.8 


185.6 


190.3 


217.4 


228.8 


277 


278 


246.9 


126.4 


130.4 


129.2 


123. 1 


181. 5 


186.3 


191 .0 


218.2 


229.6 


278 


279 


247-8 


126.9 


130.9 


129.7 


123.6 


182.2 


187.0 


191.7 


218.9 


230-5 


279 


280 


248.7 


127.3 


131-4 


130.2 


124.1 


182.8 


187-7 


192.4 


219.7 


231-3 


280 


281 


249.6 


127.8 


131-9 


130.7 


124.6 


183. 5 


188.3 


193.1 


220.5 


232-1 


281 


282 


250. S 


128.3 


1-3 2-4 


131 .2 


125.1 


184.2 


189.0 


193.9 


221 .3 


233-0 


282 


283 


251-4 


128.8 


132-9 


131-7 


125.6 


184.8 


189.7 


194.6 


222.1 


233-8 


283 


284 


252-3 


129.3 


133-4 


132.2 


126. 1 


185.5 


190.4 


195-3 


222 .9 


234.6 


284 



628 



FOOD INSPECTION AND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 
SUGAR, LACTOSE, AND MAL,TOSE— (Continued). 
[Weights in millign-ams.] 



o 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
















3 


o 


















































V 








"(3 


^^ 






d 




d 


Q> 


•a 
O 


'a 


u 





u 
a 
00 






6 


+ 
6 


+ 







+ 
6 


•a 


3 


o 


V 


u 


1-1 


0^ 
6 


rt 5P 


u 


» 


Si 


8 


a 





t-i 
a 

O 


0, 
a 




i 

Q 


> 


E 3 




1 




6 


6 


u 

0. 
a 



285 


253-2 


129.8 


133-9 


132.7 


126.6 


186.2 


191. 1 


196.0 


223.7 


235-5 


28s 


286 


254-0 


130.3 


134-4 


133-2 


127. 1 


186.9 


191. 8 


196.7 


224.5 


236.3 


286 


287 


254-9 


130.8 


134-9 


133-7 


127 .6 


187. s 


192. S 


197-4 


225.3 


237.1 


287 


288 


2SS-8 


131-3 


135-4 


134-3 


128.1 


188.2 


193-2 


198. I 


226. 1 


238.0 


288 


389 


256.7 


131-8 


135-9 


134-8 


128.6 


188.9 


193.8 


198.8 


226.9 


238.8 


289 


ago 


257-6 


132.3 


136.4 


I3S-3 


129.2 


189. s 


194. S 


199.5 


227.6 


239.6 


290 


291 


258. 5 


132.7 


136-9 


135-8 


129-7 


190.2 


195-2 


200. 2 


228.4 


240.5 


291 


292 


259-4 


133-2 


137-4 


136-3 


130.2 


190.9 


195-9 


200.9 


229. 2 


241.3 


292 


293 


260.3 


133-7 


137-9 


136.8 


130.7 


I9IS 


196. 6 


201.6 


230.0 


242.1 


293 


294 


261 .2 


134-2 


138.4 


137-3 


131-2 


192.2 


197.3 


202.3 


230.8 


242.9 


294 


295 


262 .0 


134-7 


138.9 


137-8 


131-7 


192.9 


198.0 


203.0 


231 .6 


243-8 


29s 


296 


262 .9 


135-2 


139-4 


138.3 


132.2 


193.6 


198.7 


203.7 


232.4 


244-6 


296 


297 


263.8 


135-7 


140.0 


138.8 


132.7 


194-2 


199.3 


204.4 


233-2 


245-4 


297 


298 


264.7 


136-2 


140.5 


139-4 


133-2 


194-9 


200.0 


205. I 


234.0 


246.3 


298 


299 


265.6 


136-7 


141 .0 


139-9 


133-7 


195-6 


200.7 


205 . 8 


234-8 


247-1 


299 


300 


266.5 


137-2 


141.5 


140.4 


134-2 


196.2 


201.4 


206.6 


235-5 


247.9 


300 


301 


267.4 


137-7 


142 .0 


140.9 


134-8 


196.9 


202. I 


207.3 


236.3 


248.8 


301 


302 


268.3 


138-2 


142.5 


141.4 


135-3 


197.6 


202.8 


208.0 


2371 


249.6 


302 


303 


269. 1 


138-7 


143-0 


141.9 


135-8 


198.3 


203.5 


208.7 


237-9 


250.4 


303 


304 


270.0 


139-2 


143-5 


142.4 


136.3 


198.9 


204.2 


209.4 


238.7 


251.3 


304 


30s 


270.9 


139-7 


144-0 


142.9 


136.8 


199.6 


204.9 


210. 1 


239-S 


252.1 


30s 


306 


271.8 


140. 2 


144-5 


143-4 


137-3 


200.3 


205.5 


210.8 


240.3 


252.9 


306 


307 


272.7 


140-7 


I45-0 


144.0 


137-8 


201.0 


206.2 


211. 5 


241 . 1 


253-8 


307 


308 


273.6 


141 . 2 


145-S 


144. 5 


138-3 


201.6 


206.9 


212.2 


241.9 


254.6 


308 


309 


274-5 


14I-7 


146. 1 


145-0 


138-8 


202.3 


207.6 


212.9 


242.7 


255-4 


309 


310 


275-4 


142 . 2 


146.6 


1455 


139-4 


203.0 


208.3 


2x3.7 


243-5 


256.3 


310 


311 


276-3 


142.7 


147-I 


146.0 


139-9 


203.6 


209.0 


214.4 


244.2 


257.1 


311 


312 


277.1 


143.2 


147-6 


146. 5 


140.4 


204.3 


209.7 


215.1 


245.0 


2579 


312 


313 


278.0 


143-7 


148. 1 


147.0 


140.9 


205.0 


210.4 


215. 8 


245-8 


258.8 


313 


314 


278.9 


144-2 


148.6 


147-6 


141-4 


20s. 7 


211.1 


216.5 


246.6 


259.6 


314 


31S 


279-8 


144.7 


149.1 


148. 1 


141.9 


206.3 


211. 8 


217.2 


247-4 


260. 4 


315 


316 


280.7 


145-2 


149.6 


148.6 


142.4 


207.0 


212. 5 


217.9 


248.2 


261 .2 


316 


317 


281.6 


145-7 


150. 1 


149. 1 


143-0 


207.7 


213. I 


2x8.6 


249.0 


262 . 1 


317 


318 


282.5 


146.2 


ISO. 7 


149-6 


143 -5 


ao8.4 


213.8 


219.3 


249.8 


262 . 9 


318 


319 


283.4 


146.7 


151-2 


150-1 


144.0 


309.0 


214. S 


220.0 


250.6 


263.7 


319 


320 


284.2 


147.2 


151-7 


150.7 


144-S 


209.7 


215.2 


220.7 


251.3 


264.6 


320 


321 


285.1 


147-7 


152-2 


151 -2 


145.0 


210.4 


215.9 


221.4 


252.1 


265.4 


321 


322 


286.0 


148.2 


152-7 


151-7 


145-5 


aii.o 


216.6 


222.2 


252.9 


266. 2 


322 


323 


286.9 


148.7 


153-2 


152.2 


146-0 


211. 7 


217.3 


222.9 


253.7 


267 . 1 


323 


324 


287.8 


149.2 


153-7 


152.7 


146-6 


312.4 


218.0 


223.6 


254-5 


267.9 


324 


32s 


288.7 


149.7 


154-3 


153-2 


147-1 


213. 1 


218.7 


224.3 


255-3 


268.7 


32s 


326 


289.6 


150. 2 


154-8 


153-8 


147-6 


213.7 


219.4 


225.0 


256. 1 


269.6 


326 


327 


290. 5 


150.7 


155-3 


154-3 


148. 1 


214.4 


220. I 


225.7 


256.9 


270.4 


327 


328 


291.4 


151-2 


iSS-8 


154-8 


148.6 


21S.1 


220. 7 


226.4 


257-7 


271.2 


328 


329 


292 .2 


iSi-7 


156-3 


iSS-3 


I49-I 


21S.8 


221.4 


227.1 


258.5 


272.1 


329 


330 


293-1 


152.2 


156.8 


155-8 


I t».7 


216.4 


222. I 


227.8 


259-3 


272.9 


330 


331 


294.0 


152-7 


IS7-3 


156.4 


150.2 


217. 1 


222.8 


228. 5 


260.0 


273-7 


331 


332 


294.9 


153-2 


157-9 


156.9 


150.7 


217.8 


223. S 


229.2 


260.8 


274.6 


332 


333 


295.8 


153-7 


158.4 


157-4 


151. 2 


218.4 


224. 2 


230.0 


261 .6 


275.4 


333 


334 


296.7 


154-2 


158-9 


157-9 


151-7 


219. 1 


224.9 


230.7 


262 . 4 


276.2 


334 


335 


297-6 


154-7 


159-4 


158.4 


152.3 


219.8 


225.6 


231.4 


263.2 


277-0 


335 


336 


298. 5 


ISS-2 


159-9 


1590 


152-8 


220.5 


226.3 


22.1 


264.0 


277-9 


336 


337 


299-3 


155-8 


160.5 


1 59 5 


153-3 


221 . 1 


227. 


232.8 


264.8 


278.7 


337 


338 


300.2 


156.3 


161 .0 


160 .0 


153-8 


221.8 


227.7 


233.5 


265.6 


279.5 


338 


339 


301. 1 


156-8 


161. 5 


160.5 


154.3 


222. 5 


228.3 


234-2 


266.4 


280.4 


339 



SUGAR AND SACCHARINE PRODUCTS. 



629 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 
SUGAR, LACTOSE, AND MALTOSFr— {Continued). 



[Weights in milligrams.] 



340 
341 
342 
343 

344 

34S 
346 
347 
348 
349 

35° 
351 
352 
353 
354 

355 
356 
357 
358 
359 

360 
361 
362 
363 
364 

36s 
366 
367 
368 
369 

370 
371 
372 
373 
374 

37S 
376 
377 
378 
379 

380 
381 
382 
383 
384 

38s 
386 
387 
388 
389 

390 
391 
392 
393 
394 



302.0 
302.9 
303-8 
304.7 
305-6 

306. s 
3073 
308.2 
309.1 
310.0 

310.9 

3II-8 
312.7 
313-6 
314-4 

31S-3 
316.2 
317-1 
318.0 
318.9 

319-8 
320.7 
321.6 
322.4 
323-3 

324-2 
325-1 
326.0 
326.9 
327-8 

328.7 
3295 
330.4 
331-3 
332-2 

333-1 
3340 
334-9 
33S-8 
336-7 

337-5 
338.4 
339-3 
340.2 
34I-I 

342.0 
342.9 
343-8 
344-6 
345-5 

346.4 
347-3 
348.2 
349.1 
3SO.O 



Invert Sugar 
and Sucrose. 



Lactose. 



57-3 
57-8 
s8-3 
S8.8 
59-3 

59-8 
60.3 
60.8 
61 . 4 
61 .9 

62 .4 
62 .9 
63-4 
63-9 
64.4 

64-9 
65-4 
66.0 
66.5 
67 .0 

67-5 
68.0 
68.5 
69.0 
69.6 

70. 1 
70.6 
71. 1 
71.6 
72 . 1 

72.7 
73-2 
73-7 
74-2 
74-7 

75-3 
75-8 
76.3 
76.8 
77-3 

77-9 
78.4 
78.9 
79-4 
80.0 

80. 5 
81.0 
81. S 
82.0 
82.6 

83.1 
83-6 
84.1 
84-7 
8S-2 



62 .0 
62. s 
63-1 
63-6 

64. 1 

64.6 
6s-i 
65-7 
66.2 
66.7 

67 . 2 
67.7 
68.3 
68.8 
69-3 

69.8 
70.4 
70.9 
71.4 
71.9 

72.5 
73.0 
73.5 
74.0 
74.6 

75. 1 
75.6 
76. 1 
76.7 
77.2 

77.7 
78.3 
78.8 
79.3 
79.8 

80.4 
80.9 
81.4 
82.0 
82. s 

83.0 
83.6 
84.1 
84.6 
85.2 

85.7 
86.2 
86.8 
87.3 
87.8 



88.9 



90.0 
90. 5 



O 3 



61 .0 
61.6 

62 . 1 
62.6 
63.1 

63.7 
64. 2 
64.7 

65 . 2 
65.7 

66.3 
66.8 
67.3 
67-8 
68.4 

68.9 
69-4 
70.0 
70. 5 

71 .0 

71-5 

72 . 1 
72 .6 
73-1 
73-7 

74-2 
74-7 
75-2 
75-8 
76.3 

76.8 
77-4 
77.9 
78.4 
79.0 

79.5 
80.0 
80.6 
81. 1 
81.6 

82.1 
82.7 
83.2 
83.8 
84.3 

84.8 
85.4 
85.9 
86.4 
87-0 

87-5 
88.0 
88.6 
89.1 



6 rt 



54.8 
55.4 
55-9 
56.4 
56.9 

57-5 
S8.o 
58-5 
59-0 
59-5 

60. 1 
60.6 
61. 1 
61.6 
62 .2 

62 .7 
63-2 
63-7 
64-3 
64-8 

65-3 
6s-8 
66.4 
66.9 
67-4 

67-9 
68.5 
69.0 
69 -5 
70.0 

70.6 
71. 1 
71 .6 
72 .2 
72.7 

73-2 
73.7 
74.3 
74.8 
75-3 



78. 5 
79.1 
79.6 
80.1 
80.6 

81.3 
81.7 
82.3 
82.8 
83.3 



Maltose. 



223.2 
223.8 
224. 5 
225.2 
225.9 

226. S 
227.2 
227.9 
228. 5 
229. 2 

229.9 
230.6 
231.2 
231.9 
232.6 

233.3 
233.9 
234.6 
235. 3 
236.0 

236.7 
237.3 
238.0 
238.7 
239.4 

240.0 
240.7 
241.4 
242. I 
242.7 

243.4 
244.1 
244.8 
245.4 
246. I 

246.8 
247.5 



249. 5 

250.2 
250.8 
251. 5 
252.2 
252.9 



253. 

254 
254 
25s 



256.3 

256.9 
257.6 
258.3 
259.0 
3S9.6 



229.0 
229. 7 
230.4 
231. 1 
231.8 

232. 5 
233.2 
233.9 
234.6 
235. 3 

23s. 9 
236.6 
237.3 
238.0 
238.7 

239-4 
240. I 
240. 8 
241 S 
242. 2 

242.9 
243.6 
244.3 
245.0 
245.7 

246. 4 
247.0 
247.7 
248.4 
249. I 

249.8 
250.5 
251 . 2 
251.9 
252.6 

253.3 

254.0 
254. 7 
255.4 
256. I 

256.8 

257. 5 

258. I 
258.8 
259.5 

260. 2 
260 . 9 

261 . 6 
262 .3 
263.0 

263.7 
264.4 
265. 1 
265-8 
266.5 



234-9 
235.6 
236.3 
237.0 
237.8 

238. S 
239.2 
239.9 
240.6 
241.3 

242.0 

242.7 
243.4 
244.1 
244.8 

245.6 
246.3 
247.0 
247.7 
248.4 

249.1 
249.8 
250.5 
251.2 
252.0 

252.7 
253.4 
254.1 
254.8 
255. S 

256.2 
256.9 
257.7 
•258.4 
259.1 

259.8 
260. 5 
261 .2 
261 .9 
262.6 

263.4 

264. 1 
264.8 
265.5 
266.2 

266.9 
267.6 
268.3 
269.0 
269.8 

270.5 

271 . 2 
271.9 
272.6 
373.3 



267 . 1 
267.9 
268.7 
369.5 
270.3 

271 . 1 
271 .9 
272 . 7 

273. 5 
274.3 

275-0 
275-8 
276.6 
277-4 
278.2 

279-0 
279.8 
280.6 
281.4 
282 .2 

282 .9 
283.7 
284-5 
285.3 
286.1 

286.9 

287.7 
288.5 
289.3 
290.0 

290.8 

291 .6 
292.4 
293.2 
294.0 

294.8 
295.6 
296. 4 
297.2 
297.9 

298.7 
299.5 
300.3 
301 .1 
301 .9 

302.7 
3*3. 5 
304.2 
305.0 
30s. 8 

306.6 
307.4 
308.2 
3090 
309.8 



281.2 
282 .0 
282 .9 
283.7 
284-5 

285.4 
286.2 
287 .0 
287.9 
288.7 

289-5 
290.4 
291 . 2 
292 .0 
292 .8 



340 
341 
342 
343 
344 

345 
346 
347 
348 
349 

350 
351 
352 
353 
354 



293 


7 


355 


294 


5 


3S6 


295 


3 


357 


296 


2 


3S8 


297 





359 


297 


8 


360 


298 


7 


361 


299 


5 


362 


300 


3 


363 


301 


2 


364 


302 





365 


302 


8 


366 


301 


6 


367 


104 


5 


368 


305 


3 


369 


306 


I 


370 


307 





371 


.107 


8 


372 


308 


6 


373 


309 


5 


374 


310 


3 


375 


311 


I 


376 


.^12 





377 


312 


8 


378 


313 


6 


379 


314 


5 


380 


^15 


3 


381 


316 


I 


383 


316 


9 


383 


317 


8 


384 


318 


6 


38s 


319 


4 


386 


320 


3 


387 


321 


I 


388 


321 


9 


389 


322 


8 


390 


323 


6 


391 


324 


4 


392 


325 


2 


393 


326 


I 


394 



630 



FOOD INSPECTION AND ANALYSIS. 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— (Continued). 

[Weights in milligrams.] 



Q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





3 
















3 


o 







































0" 










V 








H 


^^ 






d 




d 


« 


•0 


^ 













X 


ffi 




w 


•a 

•a 


O 

(A 


3 



^ 


00 
3 

to 


2 V-' 


.i 


+ 


+ 


.; 


-f 





s 


h 







J? rt 


6 S, 


d 


6 


d 


d 


d 


3 


s 

3 


0. 
0. 



i 


u 

> 
13 




2^ 
0^ 










X 


s 

a 

3 


o 





Q 


HH 


d 


" 





6 





u 


u 





395 


350.9 


185.7 


191 .0 


190.2 


183.9 


260.3 


267.2 


274.0 


310.6 


326.9 


39S 


396 


351.8 


186.2 


191. 6 


190.7 


184.4 


261 .0 


267.9 


274.7 


311-4 


327.7 


396 


397 


352.6 


186.8 


192. 1 


191. 3 


184.9 


261 .7 


268.6 


275.5 


312.1 


328.6 


397 


398 


353-5 


187.3 


192.7 


191.8 


185.5 


262.3 


269.3 


276. 2 


312.9 


3294 


398 


399 


354-4 


187.8 


193-2 


192.3 


186.0 


263.0 


269.9 


276.9 


313-7 


330.2 


399 


400 


335-3 


188.4 


193-7 


192.9 


186. 5 


263.7 


270.6 


277.6 


314-s 


331-1 


400 


401 


356-2 


188.9 


194-3 


193-4 


187. 1 


264.4 


271.3 


278.3 


31S-3 


331-9 


401 


402 


3S7-I 


189.4 


194-8 


194.0 


187.6 


265.0 


272.0 


279.0 


316. 1 


332.7 


403 


403 


358-0 


189.9 


195-4 


194-S 


188.1 


265.7 


272.7 


279.7 


316.9 


333-6 


403 


404 


358-9 


190. 5 


195-9 


I9S-0 


188.7 


266.4 


273.4 


280.4 


317-7 


334-4 


404 


40 s 


359-7 


191.0 


196.4 


195-6 


189.2 


267. 1 


274. 1 


281. 1 


318. 5 


335-2 


40s 


406 


360.6 


191. 5 


197.0 


196. 1 


189.8 


267.8 


274-8 


281.9 


319.2 


336.0 


406 


-.07 


361.5 


192 . 1 


197.5 


196.7 


190.3 


268.4 


275-5 


282.6 


320.0 


336.9 


407 


408 


362.4 


192 .6 


198.1 


197.2 


190.8 


269. 1 


276. 2 


283.3 


320.8 


337-7 


408 


409 


363-3 


193 -I 


198.6 


197-7 


191. 4 


269.8 


276.9 


284.0 


321.6 


338.5 


409 


410 


364-2 


193-7 


199.1 


198-3 


191. 9 


270. 5 


277.6 


284.7 


322.4 


339-4 


410 


411 


365-1 


194.2 


199.7 


198-8 


192.5 


271.2 


278.3 


285.4 


323-2 


340.2 


411 


412 


366.0 


194-7 


200. 2 


199.4 


193.0 


271.8 


279.0 


286.2 


324-0 


341-0 


412 


413 


366.9 


195-2 


200.8 


199.9 


193.5 


272. 5 


279.7 


286.9 


324.8 


341-9 


413 


414 


367-7 


195-8 


201.3 


200.5 


194.1 


273.2 


280. 4 


287.6 


325-6 


342.7 


414 


41S 


36^.6 


196.3 


201.8 


201 .0 


194.6 


273.9 


281. I 


288.3 


326.3 


343-5 


41s 


416 


369. 5 


196.8 


202 .4 


201 .6 


195.2 


274-6 


281.8 


289.0 


327.1 


344-4 


416 


417 


370.4 


197-4 


202 .9 


202 . 1 


195.7 


275.2 


282. s 


289.7 


327-9 


345-2 


417 


418 


371-3 


197.9 


203.5 


202 .6 


196 . 2 


275.9 


283.2 


290.4 


328.7 


346.0 


418 


419 


372.2 


198.4 


204.0 


203.2 


196.8 


276.6 


283.9 


291 .2 


329-S 


346.8 


419 


(30 


373-1 


199.0 


204.6 


203.7 


197-3 


277.3 


284.6 


291.9 


330.3 


347-7 


420 


421 


3740 


199.5 


205. I 


204.3 


197.9 


277.9 


285.3 


292.6 


331-1 


348.5 


421 


422 


374-8 


200. I 


205.7 


204.8 


198.4 


278.6 


286.0 


293.3 


331-9 


349-3 


42a 


423 


375-7 


200.6 


206. 2 


205.4 


198.9 


279.3 


286.7 


294.0 


332.7 


3SO-2 


423 


424 


376-6 


201 . I 


206. 7 


205.9 


199-5 


280.0 


287.4 


294.7 


333-4 


3S1-0 


424 


42s 


377-5 


201 . 7 


207.3 


206.5 


200.0 


280.7 


288. I 


295-4 


334-2 


3SI-8 


42s 


426 


378.4 


202 . 2 


207.8 


207 .0 


200 . 6 


281.3 


288.8 


296. 2 


33S-0 


352-7 


426 


427 


379-3 


202 .8 


208.4 


207 .6 


201 . I 


282.0 


289.4 


296.9 


335-8 


353-5 


427 


428 


380.2 


203.3 


208.9 


208.1 


201.7 


282.7 


290. I 


297.6 


336.6 


354-3 


428 


429 


381. I 


203.8 


209.5 


208.7 


202 . 2 


283.4 


290. 8 


298.3 


337-4 


355-1 


429 


430 


382.0 


204.4 


210.0 


209 . 2 


202 . 7 


284.1 


291.5 


299.0 


338-2 


356.0 


430 


431 


382.8 


204.9 


210.6 


209. 8 


203.3 


284.7 


202 . 2 


299.7 


339-0 


356.8 


431 


432 


383-7 


205.5 


211.1 


210.3 


203.8 


285.4 


292.9 


300. s 


339-7 


357-6 


43a 


433 


384-6 


206.0 


211.7 


210.9 


204.4 


286.1 


293.6 


301.2 


340.5 


3.S8.5 


433 


434 


385-5 


206. s 


212.2 


211.4 


204.9 


286.8 


294.3 


301.9 


341-3 


359-3 


434 


435 


386.4 


207 . 1 


212.8 


212.0 


205-5 


287.5 


295.0 


302.6 


342.1 


360.1 


43S 


436 


387-3 


207 .6 


213.3 


212.5 


206.0 


288. I 


295. 7 


303.3 


342.9 


361 .0 


436 


437 


388.2 


208. 2 


213.9 


213. I 


206 . 6 


288.8 


296.4 


304.0 


343-7 


361.8 


437 


438 


389-1 


208.7 


214.4 


213 .6 


207 . 1 


289. S 


297. I 


304.7 


344-5 


362.6 


438 


439 


390-0 


209.2 


215.0 


214.2 


207.7 


290.2 


297.8 


305. 5 


345-3 


363-4 


439 


440 


390.8 


209.8 


2 15 5 


214.7 


208.2 


290.9 


298 . S 


306.3 


346.1 


364-3 


440 


441 


391.7 


210.3 


216. 1 


215-3 


208.8 


291. s 


299.2 


306.9 


346.8 


365. I 


441 


442 


392.6 


210.9 


216.6 


215.8 


209.3 


302.2 


299.9 


.^07.6 


347-6 


365-9 


442 


443 


393-5 


2H . 4 


217.2 


216.4 


209.9 


392.9 


300.6 


308.3 


348.4 


366.8 


443 


444 


394.4 


212.0 


217.8 


216.9 


210.4 


293.6 


301.3 


309.0 


349-2 


567-6 


444 


445 


395-3 


212. S 


218.3 


217.5 


211.0 


294.2 


302.0 


309-7 


350-0 


368.4 


445 


446 


396.2 


213.1 


218.9 


218.0 


2 1 1 . 5 


294-9 


302.7 


310. s 


350.8 


3693 


446 


447 


397-1 


213.6 


219.4 


218.6 


212 . 1 


295.6 


303.4 


311.2 


3SI-6 


370.1 


447 


448 


397-9 


214 I 


220 .0 


2 19. I 


212.6 


296.3 


304.1 


311. 9 


352-4 


370.9 


448 


449 


398.8 


214.7 


220.5 


219.7 


213.2 


397.0 


304.8 


312. <5 


353-2 


371-7 


449 



SUGAR AND SACCHARINE PRODUCTS, 



631 



MUNSON AND WALKER'S TABLE FOR CALCULATING DEXTROSE, INVERT 

SUGAR, LACTOSE, AND MALTOSE— {Continued). 

[Weights in milligrams.] 



q 








Invert Sugar 
and Sucrose. 


Lactose. 


Maltose. 





s 
















3 


o 







































Q 










9) 








"rt 


_ 






d 




d 


a 


■d 
O 


S 




si 


M 

3 




C4 





+ 


+ 




+ 


13 

(0 


3 


u 







<5 rt 


B S 


6 


d 


6 


d 


d 


3 


O 


^ 


Ui 




3 


S <^ 


a 


;:! 


a 


fi 


s< 





a 

3 


0. 
0. 



1) 


V 

> 


u 3 
0^ 


X 


ffi 


ffi 


X 


ffi 


u 

a 
3 


o 





Q 




6 


r. 


u 





(J 


6 


6 





45° 


399-7 


215-2 


221 . I 


220 . 2 


213.7 


297-6 


305 -s 


313.3 


353-9 


372.6 


450 


451 


400 . 6 


215-8 


221 .6 


220.8 


214.3 


298.3 


306.2 


314-0 


354-7 


373-4 


451 


452 


401.5 


216.3 


222.2 


221.4 


214.8 


299.0 


306.9 


314-7 


355-5 


374-2 


452 


453 


402.4 


216.9 


222 .8 


221 .9 


215.4 


299.7 


307-6 


315-5 


356.3 


375.1 


453 


454 


403 -3 


217.4 


223.3 


222 . 5 


215. 9 


300.4 


308.3 


316.2 


357- I 


375.9 


454 


455 


404.2 


218.0 


223.9 


223.0 


216.5 


301. 1 


309-0 


316.9 


357-9 


376.7 


455 


456 


405-1 


218. 5 


224.4 


223.6 


217.0 


301-7 


309-7 


317.6 


358.7 


377.6 


456 


457 


405-9 


219. 1 


225.0 


224. 1 


217.6 


302.4 


310.4 


318.3 


359-5 


378.4 


457 


458 


406.8 


219.6 


225. 5 


224.7 


218. I 


303-1 


311- 1 


3190 


360.3 


379-2 


458 


459 


407.7 


220 . 2 


226. 1 


225.3 


218.7 


303-8 


311-8 


319-8 


361 .0 


380.0 


459 


460 


408.6 


220. 7 


226.7 


225.8 


219.2 


304. s 


312. s 


320. 5 


361.8 


380.9 


460 


461 


409.5 


221.3 


227.2 


226.4 


219.8 


30s. I 


313-2 


321 .2 


362.6 


381.7 


461 


462 


410.4 


221.8 


227.8 


226 . Q 


'>20.3 


305-8 


313-9 


321.9 


363-4 


382.5 


462 


463 


411 -3 


222 . 4 


228.3 


227.5 


220 9 


306.5 


314-6 


322.6 


364-2 


383-4 


463 


464 


4T2 . 2 


222 .9 


228.9 


228.1 


221.4 


307.2 


315-3 


323-4 


365.0 


384-2 


464 


46s 


413-0 


223-5 


229.5 


228.6 


222 .0 


307-9 


316.0 


324-1 


365.8 


385-0 


465 


466 


413-9 


224.0 


230.0 


229.2 


222.5 


308.6 


316.7 


324-8 


366.6 


385-9 


•466 


467 


414-8 


224.6 


230.6 


229.7 


223.1 


309-2 


317-4 


325.5 


367-3 


386.7 


467 


468 


415-7 


225.1 


231.2 


230-3 


223.7 


309-9 


318. 1 


326.2 


368.1 


387-5 


468 


469 


416.6 


225.7 


231.7 


230.9 


224.2 


310.6 


318.8 


326.9 


368.9 


388.3 


469 


470 


417-5 


226.2 


232.3 


231.4 


224.8 


3II-3 


319-5 


327-7 


369-7 


389-2 


470 


471 


418.4 


226.8 


232.8 


232 .0 


225.3 


312.0 


320.2 


328.4 


370.5 


390.0 


471 


472 


419-3 


227.4 


233-4 


232.5 


225.9 


312.6 


320.9 


329.1 


371 -3 


390.8 


472 


473 


420. 2 


227.9 


234.0 


233-1 


226.4 


313-3 


321 .6 


329.8 


372- I 


391-7 


473 


474 


421 .0 


228. 5 


234-5 


233-7 


227 .0 


314-0 


322.3 


330. S 


372.9 


392.5 


474 


475 


421 .9 


229.0 


235-1 


234-2 


227 .6 


314-7 


323 -0 


331 3 


373-7 


393-3 


47S 


476 


422.8 


229.6 


235-7 


234.8 


228.1 


3IS-4 


323.7 


332.0 


374-4 


394-2 


476 


477 


423-7 


230.1 


236.2 


235.4 


228.7 


316. 1 


324.4 


332.7 


375-2 


395-0 


477 


478 


424.6 


230.7 


236.8 


235-9 


229. 2 


316.7 


325.1 


333.4 


376.0 


395-8 


47» 


479 


425-5 


231-3 


237-4 


236.5 


229.8 


317.4 


325.8 


334-1 


376.8 


396.6 


479 


480 


426.4 


231.8 


237-9 


237-1 


230.3 


318. 1 


326. S 


334-8 


377-6 


397-5 


480 


481 


427-3 


232.4 


238-5 


237-6 


230.9 


318.8 


327.2 


335-6 


378-4 


398.3 


481 


482 


428.1 


232.9 


239-1 


238.2 


231-S 


3I9-S 


3279 


336.3 


379-2 


399- I 


482 


483 


429-0 


233-5 


239.6 


238.8 


232-0 


320. 1 


328.6 


337-0 


380.0 


400 . 


483 


484 


429.9 


234.1 


240. 2 


239-3 


232 -6 


320.8 


329-3 


337.7 


380.7 


400. 8 


484 


48s 


430.8 


234.6 


240 .8 


239-9 


233-3 


321.5 


330.0 


338-4 


381. 5 


401 .6 


48s 


486 


431-7 


235.2 


241.4 


240.5 


233-7 


322.2 


30.7 


339-1 


382.3 


402.4 


486 


487 


432.6 


235.7 


241 .9 


241 .0 


234-3 


322.9 


331-4 


339-9 


383-1 


403-3 


487 


488 


433-5 


266.3 


242. 5 


241.6 


234.8 


323-6 


332.1 


340.6 


383.9 


404.1 


488 


489 


434-4 


236.9 


243.1 


242.2 


235.4 


324-2 


332.8 


341-3 


384.7 


404.9 


489 


490 


435-3 


237-4 


243-6 


242-7 


236.0 


324 9 


333.5 


342.0 


385.5 


405.8 


490 



632 FOOD INSPECTION AND ANALYSIS. 

Allihn's Method for the Determmation of Dextrose.* — The solutions 
used are those described on page 615, except that 125 grams of potassium 
hydroxide are used in place of 50 grams of sodium hydroxide in preparing 
the alkaline tartrate solution. Place 30 cc. of Fehling's copper solution, 
30 cc. of the alkaline tartrate solution, and 60 cc. of water in a beaker 
and heat to boiling. Add 25 cc. of the sugar solution, which must be 
so prepared as not to contain more than 1% dextrose, and boil over the 
flame for two minutes. Filter immediately without diluting through a 
Gooch crucible containing a layer of asbestos fiber, prepared as described 
on page 618, and wash thoroughly with hot water, using reduced pressure. 
Transfer the asbestos fiber and the adhering cuprous oxide by means of 
a glass rod to a beaker and rinse the crucible with about 30 cc. of a boiling 
mixture of dilute sulphuric and nitric acids containing 65 cc. of sulphuric 
acid (specific gravity 1.84) and 50 cc. of nitric acid (specific gravity 1.42) 
per liter. Heat and agitate till the solution is complete, then filter into a 
scrupulously clean, tared platinum dish of loo-cc. capacity, taking care 
to wash out all the copper solution from the filter into the dish. Deposit 
the copper electrolytically in the platinum dish and weigh. Determine 
the dextrose from Allihn's table, pages 633-634. 

Or, the metallic copper may be calculated by means of the factor 
0.7989 from the cupric oxide obtained as in Defren's method (page 618) 
and Allihn's table used. 

Or, the cuprous oxide as directly obtained by either Allihn's or Defren's 
method may be washed with alcohol and ether, dried for twenty minutes 
at 100° C, and weighed, its equivalent in dextrose being ascertained from 
Allihn's table. 

Browne's Correction Formula,'^ for use when the Allihn method is 
carried out on samples containing a considerable amount of sucrose, is as 
follows : 



C= 



£>+4o' 



in which C = correction in milligrams to be deducted from dextrose found, 
»S = milligrams of sucrose, and D = milligrams of dextrose. 

He found that the reducing action of sucrose is proportional (i) to the 
concentration of the sucrose and (2) to the amount of unreduced copper. 
In the volumetric methods and in the gravimetric methods when the amount 

* Jour. prak. Chem., 22, 1880, p. 46. 
t Jour. Amer. Chem. Soc, 1906, p. 451. 



SUGAR AND SACCHARINE PRODUCTS. 



633 





ALLIHN'S TABLE 


FOR THE DETERMINATION OF DEXTROSE 




Milli- 


MilU- 


Mim- 


Milli- 


Milli- 


MilH- 


MilU- 


Mim- 


MilU- 


MilH- 


Milli- 


MilU- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


II 


12.4 


6.6 


76 


85.6 


38.8 


141 


158.7 


71.8 


206 


231-9 


105.8 


12 


13-5 


7.1 


77 


86.7 


39.3 


142 


159-9 


72.3 


207 


233-0 


106.3 


13 


14.6 


7.6 


78 


87.8 


39.8 


143 


161 .0 


72.9 


208 


234-2 


106.8 


14 


iS-8 


8. I 


79 


88.9 


40.3 


144 


162. I 


73-4 


209 


235-3 


107.4 


15 


16.9 


8.6 


80 


90. 1 


40.8 


145 


163.2 


73.9 


2IO 


236.4 


107.9 


i6 


18.0 


9.0 


81 


91.2 


41.3 


146 


164.4 


74-4 


211 


237-6 


108.4 


17 


ig.i 


9-5 


82 


92.3 


41.8 


147 


165.5 


74-9 


21 2 


238.7 


109.0 


i8 


20.3 


10. 


83 


93-4 


42.3 


148 


166.6 


75-5 


213 


239-8 


I09-S 


19 


21.4 


lO-S 


84 


94-6 


42.8 


149 


167.7 


76.0 


214 


240.9 


IIO.O 


20 


22. s 


II .0 


85 


95.7 


43.4 


150 


168.9 


76.5 


215 


242. 1 


110.6 


31 


23.6 


ii-S 


86 


96.8 


43-9 


151 


170.0 


77-0 


216 


243.2 


III . I 


32 


24.8 


12.0 


87 


97-9 


44-4 


152 


171. I 


77-5 


217 


244-3 


III .6 


23 


25-9 


12.5 


88 


99 I 


44-9 


153 


172-3 


78.1 


218 


245.4 


112. 1 


24 


27 .0 


13.0 


89 


100. 2 


45.4 


154 


173-4 


78.6 


219 


246. 6 


112. 7 


2S 


28.1 


13. s 


90 


loi . 3 


45-9 


155 


174-5 


79.1 


220 


247-7 


ii3-a 


26 


29 -3 


14.0 


91 


102.4 


46.4 


156 


175.6 


79-6 


221 


248.7 


113.7 


27 


30.4 


14-5 


92 


103 . 6 


46.9 


157 


176.8 


80.1 


222 


249-9 


II4-3 


38 


31-5 


15.0 


93 


104.7 


47-4 


158 


177.9 


80.7 


223 


251.0 


114. 8 


29 


32-7 


15-5 


94 


105.8 


47.9 


159 


179.0 


81.2 


224 


252.4 


115-3 


30 


33-8 


16.0 


95 


107 . 


48.4 


160 


180. I 


81.7 


225 


253-3 


115.9 


31 


34-9 


16.5 


96 


108. 1 


48.9 


161 


181. 3 


82.2 


226 


254.4 


1 16.4 


32 


36.0 


17.0 


97 


109. 2 


49-4 


162 


182.4 


82.7 


227 


255-6 


116.9 


33 


37-2 


17-5 


98 


no. 3 


49-9 


163 


183-5 


83-3 


228 


256.7 


117.4 


34 


38.3 


18.0 


99 


iii.S 


SO. 4 


164 


184.6 


83-8 


229 


257-8 


118. 


35 


39-4 


18. s 


100 


112 . 6 


50.9 


1 65 


185.8 


84-3 


230 


258.9 


118. s 


36 


40. 5 


18.9 


lOI 


113-7 


51-4 


166 


186.9 


84.8 


231 


260. I 


119.0 


37 


41.7 


19.4 


102 


114. 8 


51-9 


167 


188.0 


8S-3 


232 


261 . 2 


119.6 


38 


42.8 


19.9 


103 


1 16 . 


52-4 


168 


189. I 


85-9 


233 


262.3 


120. 1 


39 


43-9 


20. 4 


104 


117.1 


52.9 


169 


190.3 


86.4 


234 


263.4 


120.7 


40 


45.0 


20. 9 


105 


118. 2 


53-5 


170 


191-4 


86.9 


23s 


264 6 


121 . 2 


41 


46. 2 


21.4 


106 


119-3 


54-0 


171 


192.5 


87.4 


236 


265.7 


121.7 


42 


47-3 


21 .9 


107 


120. S 


54-5 


172 


193.6 


87.9 


237 


266.8 


122.3 


43 


48.4 


22.4 


108 


1 21 . 6 


55-0 


173 


194.8 


88.5 


238 


268.0 


122.8 


44 


49-5 


22.9 


109 


122.7 


55.5 


174 


195.9 


89.0 


239 


269. 1 


123.4 


45 


5° -7 


23.4 


no 


123.8 


56.0 


175 


197.0 


89. 5 


240 


270. 2 


123-9 


46 


SI. 8 


239 


III 


125.0 


56. 5 


176 


198. I 


90.0 


241 


271.3 


124.4 


47 


52.9 


24.4 


I 12 


126. 1 


57-0 


177 


199-3 


90.5 


242 


272. 5 


125.0 


48 


54-0 


24.9 


113 


127.2 


57-5 


178 


200.4 


91. 1 


243 


273-6 


125.5 


49 


55-2 


25-4 


114 


128.3 


58.0 


179 


201 . 5 


91 .6 


244 


274-7 


126.0 


5° 


56.3 


25-9 


IIS 


129.6 


58.6 


180 


202.6 


92.1 


245 


275.8 


126.6 


SI 


S7-4 


26.4 


116 


130.6 


59-1 


181 


203.8 


92.6 


246 


277.0 


127 . 1 


52 


58.5 


26.9 


117 


131-7 


59-6 


182 


204.9 


93.1 


247 


278.1 


127 . 6 


53 


59-7 


27.4 


118 


132.8 


60. 1 


183 


206.0 


93-7 


248 


279.2 


128. 1 


54 


60.8 


27.9 


119 


134-0 


60.6 


184 


207 . 1 


94-2 


249 


280.3 


128.7 


55 


61 . 9 


28.4 


120 


13S-I 


61. 1 


185 


208.3 


94-7 


250 


281.5 


129? 2 


56 


63.0 


28.8 


121 


136. 2 


61.6 


186 


209.4 


95-2 


251 


282.6 


129-7 


57 


64.2 


29 -3 


122 


137-4 


62.1 


187 


210.5 


95-7 


252 


283.7 


130.3 


58 


65.3 


29.8 


123 


138-5 


62.6 


188 


211.7 


96-3 


253 


284.8 


130.8 


59 


66.4 


30.3 


124 


139-6 


63-1 


189 


212.8 


96.8 


254 


286.0 


131-4 


60 


67.6 


30.8 


125 


140.7 


63.7 


190 


2139 


97.3 


255 


287.1 


131-9 


61 


68.7 


31.3 


126 


141-9 


64. 2 


191 


215.0 


97.8 


256 


288.2 


132.4 


62 


69.8 


31.8 


127 


143.0 


64.7 


192 


216.2 


98.4 


257 


289.3 


133-0 


63 


70.9 


32.3 


128 


144-1 


65.2 


193 


217-3 


98.9 


258 


290.5 


133.5 


64 


72.1 


32.8 


129 


145-2 


65-7 


194 


218.4 


99-4 


259 


291 . 6 


134-1 


65 


73-2 


33-3 


130 


146-4 


66.2 


195 


219-5 


100. 


260 


292.7 


134-6 


66 


74-3 


33-8 


131 


147 -5 


66.7 


196 


220. 7 


100. 5 


261 


293.8 


I35-I 


67 


75-4 


34-3 


132 


148.6 


67 . 2 


197 


221.8 


loi .0 


262 


295.0 


135-7 


68 


76.6 


34-8 


133 


149.7 


67.7 


198 


222 . 9 


101 . 5 


263 


296. 1 


136.2 


69 


77-7 


35-3 


134 


150.9 


68.2 


199 


224.0 


102.0 


264 


297.2 


136.8 


70 


78.8 


35-8 


135 


152.0 


68.8 


200 


225.2 


102 . 6 


265 


298.3 


137-3 


71 


79-9 


36.3 


136 


1S3-I 


69.3 


201 


226.3 


103.1 


266 


299-5 


137-8 


72 


81. I 


36.8 


137 


154-2 


6g.8 


202 


227.4 


103-7 


267 


300. 6 


138.4 


73 


82.2 


37-3 


138 


iSS-4 


70.3 


203 


228.5 


104. 2 


268 


301.7 


138-9 


74 


83.3 


37.8 


139 


156-5 


70.8 


204 


229.7 


104.7 


269 


3^2.8 


139-5 


75 


84.4 


38.3 


140 


IS7-6 


71.3 


20S 


230.8 


105.3 


270 


304.0 


140.0 



634 



FOOD INSPECTION AND ANALYSIS. 



ALLIHN'S TABLE FOR THE DETERMINATION OF DEXTROSE— (Continued). 


MilU- 


MilH- 


Milli- 


MilH- 


Milli- 


Milli- 


Milli- 


MilU- 


Milli- 


MilU- 


Milli- 


Milli- 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


grams 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


of 


of Cu- 


of 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


Cop- 


prous 


Dex- 


per. 


Oxide. 


trose. 


per. 


O.Kide. 


trose. 


per. 


Oxide. 


trose. 


per. 


Oxide. 


trose. 


271 


30s I 


140.6 


321 


361.4 


168. 1 


371 


417-7 


196.3 


421 


474.0 


225.1 


272 


306. 2 


141 . 1 


322 


362. 5 


168.6 


372 


418.8 


196.8 


422 


475-6 


225.7 


273 


307.3 


141.7 


323 


363-7 


169. 2 


373 


420. 


197-4 


423 


476.2 


226. 3 


274 


308. 5 


142. 2 


324 


364-8 


169.7 


374 


421 . 1 


198.0 


424 


477-4 


226.9 


27s 


309-6 


142.8 


325 


365-9 


170.3 


375 


422 . 2 


198.6 


425 


478.5 


227.5 


276 


3IO-7 


143-3 


326 


367.0 


170.9 


376 


4233 


199-1 


426 


479-6 


228.0 


277 


3II-9 


143-9 


327 


368.2 


171-4 


377 


424-5 


199-7 


427 


480.7 


228.6 


278 


313-0 


144.4 


328 


369-3 


172.0 


378 


425-6 


200.3 


428 


481.9 


229. 2 


279 


314-1 


145-0 


329 


370-4 


172.5 


379 


426.7 


200.8 


429 


483.0 


229.8 


280 


315-2 


145-5 


330 


371-5 


173-1 


380 


427.8 


201 .4 


430 


484.1 


230.4 


281 


316.4 


146. I 


331 


372.7 


173-7 


381 


429.0 


202 .0 


431 


485-3 


231.0 


282 


3I7-S 


146. 6 


332 


373-8 


174-2 


382 


430.1 


202. s 


432 


486.4 


231.6 


283 


318.6 


147.2 


333 


374-9 


174-8 


383 


431.2 


203.1 


433 


487-5 


232. 2 


284 


319-7 


147-7 


334 


376-0 


175-3 


384 


432.3 


203.7 


434 


488.6 


232.8 


28s 


320-9 


148.3 


335 


377-2 


175-9 


385 


433.5 


204.3 


435 


489-7 


233-4 


286 


322.0 


148.8 


336 


378.3 


176-5 


386 


434-6 


204. 8 


436 


490-9 


233-9 


287 


323-1 


149-4 


337 


379-4 


177-0 


387 


435-7 


20s -4 


437 


492.0 


234-5 


288 


324.2 


149-9 


338 


380.5 


177-6 


388 


436.8 


206. 


438 


493-1 


235-1 


289 


325-4 


150.5 


339 


381-7 


178. I 


389 


438.0 


206.5 


439 


494-3 


235-7 


290 


326. S 


151 -0 


340 


382.8 


178.7 


390 


439-1 


207 . 1 


440 


495-4 


236.3 


291 


327.4 


151.6 


341 


383-9 


179-3 


391 


440.2 


207.7 


441 


496-5 


236.9 


292 


328.7 


152.1 


342 


385.0 


179-8 


392 


441-3 


208.3 


442 


497-6 


237-5 


293 


329.9 


152.7 


343 


386.2 


180. 4 


393 


442.4 


208.8 


443 


498-8 


238.1 


294 


331.0 


153.2 


344 


387.3 


180 .9 


394 


443-6 


209.4 


444 


499-9 


238.7 


29s 


332.1 


153-8 


345 


388.4 


181. 5 


395 


444-7 


210. 


445 


501 .0 


239-3 


296 


333-3 


154-3 


346 


389.6 


182. 1 


396 


445-9 


210.6 


446 


502 . I 


239.8 


297 


334-4 


154-9 


347 


390.7 


182.6 


397 


447.0 


21 1 . 2 


447 


503-2 


240.4 


298 


335-5 


155-4 


348 


391.8 


183-2 


398 


448.1 


211. 7 


448 


S04-4 


241 . 


299 


336-6 


156.0 


349 


392.9 


183-7 


399 


449. 2 


212.3 


449 


505-5 


241 . 6 


300 


337-8 


156-., 


350 


394.0 


184-3 


400 


450.3 


212.9 


4SO 


506.6 


242.2 


301 


338-9 


157-1 


351 


395.2 


184.9 


401 


451-5 


213-5 


451 


507-8 


242.8 


302 


340.0 


157-6 


352 


396.3 


185-4 


402 


452.6 


214. I 


452 


508.9 


243-4 


303 


341. 1 


158.2 


353 


397-4 


186.0 


403 


453-7 


214.6 


453 


510.0 


244.0 


304 


342.3 


158-7 


354 


398.6 


186.6 


404 


454-8 


215.2 


454 


511-I 


244-6 


30s 


343.4 


159-3 


355 


399-7 


187.2 


40s 


456.0 


215.8 


455 


512. 3 


245-2 


306 


344-5 


159.8 


356 


400. 8 


187-7 


406 


457-1 


216.4 


456 


513-4 


245-7 


Moy 


345-6 


160. 4 


357 


401.9 


188.3 


407 


458-2 


217.0 


457 


514-S 


246.3 


31-8 


346.8 


160.9 


358 


403 . 1 


188.9 


408 


459-4 


217-5 


458 


515-6 


246.9 


309 


347.9 


161.5 


359 


404.2 


189.4 


409 


460 . 5 


218. I 


459 


516.8 


247-5 


310 


349.0 


162.0 


360 


405-3 


190.0 


410 


461.6 


218.7 


460 


517-9 


248.1 


311 


350.1 


162.6 


361 


406. 4 


190. 6 


411 


462.7 


219.3 


461 


519-0 


248.7 


312 


351.3 


163. I 


362 


407.6 


191 . 1 


412 


463.8 


219.9 


462 


520. I 


249-3 


313 


352.4 


163-7 


363 


408.7 


191-7 


413 


465-0 


220 . 4 


463 


521.3 


249-9 


314 


353-5 


164. 2 


364 


409.8 


192.3 


414 


466. 1 


221.0 








. 3IS 


354.6 


164.8 


365 


410.9 


192.9 


415 


467.2 


221 . 6 








316 


355. 8 


165-3 


366 


412. 1 


193-4 


416 


468.4 


222. 2 








317 


356.9 


165.9 


367 


413-2 


194.0 


417 


469-5 


222.8 








318 


358.0 


166. 4 


368 


414-3 


194.6 


418 


470.6 


223.3 








339 


359-1 


167 .0 


369 


415-4 


195. 1 


419 


471.8 


223.9 








320 


360.3 


167-5 


370 


416.6 


195-7 


420 


472.9 


224. 5 









of reducing sugars is sufficient to remove nearly all the copper from the 
solution, the error due to sucrose is but slight. 

Electrolytic Apparatus. — The author has devised the apparatus shown 
in Fig. no for the electrolytic deposition of copper in sugar analysis and for 
other work of like nature. A, Fig. no, is a hard-rubber plate 50 cm. 
long and 25 cm. wide provided with four insulated metal binding posts, B, 
each carrying at the top a thumb screw by which a coiled platinum wire 



SUGAR AND SACCHARAINE PRODUCTS. 



635 




Fig. iio. — Four Pan Electrolytic Apparatus, shown (above) with Glass-covered Top 
Partially Removed, and (below) in Diagram. 



636 FOOD INSPECTION AND ANALYSIS. 

electrode, C, may be attached. In front of each post is a copper plate 
about 4 cm. square covered with thin platinum foil, P, which is bent 
around the edges of the copper plate and so held in place, the copper plate 
being screwed to the rubber from beneath. On the square platinum- 
covered plate is set the platinum evaporating-dish which holds the solu- 
tion from which the copper is to be deposited, the inside of the dish form- 
ing the cathode, while the electrode C, dipping below the surface of the 
solution, forms the anode. In front of each platinum-covered plate 
is a switch, S, and at either end of the hard-rubber plate is a binding 
post, R, for connection with the electric current. The wiring, which 
is on the under side of the rubber plate, is best illustrated by the diagram 
in Fig. no. 

Four determinations may be carried on simultaneously in four plat- 
inum dishes, if desired, the wiring and the switches being so arranged 
that beginning at one end of the plate either the first dish or the first 
two or three may be thrown in or out of circuit at will without inter- 
rupting the current through the remaining dishes. A cover with wooden 
sides and glass top fits closely over the whole apparatus as a protec- 
tion from dust, but may be easily lifted off to manipulate the dishes when 
desked. The sides of the cover are perforated to permit the escape of the 
gas formed during the electrolysis. 

The ordinary street current is used when available, and the strength 
of the current may be varied within wide limits by means of a number 
of 1 6 or 32 candle-power lamps, K, coupled in multiple, and a rheostat, 
L, consisting of a vertical glass tube sealed at the bottom, containing a 
column of dilute acid, the resistance being changed by varying the length 
of the acid column contained between the two platinum terminals immersed 
therein, one of which is movable. A gravity battery of four cells may 
be employed if the laboratory is not equipped with electric lights. 

In using this apparatus for determining copper, as in sugar work 
the plating process should go on till all the copper is deposited, requiring 
several hours or over night with a current strength of about 0.25 ampere. 
Before stopping the process, the absence of copper in the solution should 
be proved by removing a few drops with a pipette, adding first ammonia, 
then acetic acid, and testing with ferrocyanide of potassium. If no 
brown coloration is produced, all the copper has been plated out. Throw 
the dish out of circuit by means of the switch, pour out the acid solution 
quickly before it has a chance to dissolve any of the copper, wash the 
dish first with water and then with alcohol, dry, and weigh. 



SUGAR AND SACCHARINE PRODUCTS. 637 

The copper may be removed from the platinum dish by strong nitric 
acid. 

The Ross Apparatus^ consists of a funnel tube provided with a stop 
cock and a spiral of platinum wire one end of which passes through and is 
fused into the glass at the constriction. In using the apparatus form an 
asbestos mat in the constriction with the aid of suction, reduce the cuprous 
oxide by a suitable method, and filter and wash through the asbestos mat 
in the same manner as on a Gooch crucible. Close the stop cock, add 
dilute nitric acid (4 : 100) suflScient to nearly fill the tube, introduce a plati- 
num cylinder to serve as the cathode, and use the spiral as the anode. 
Employ a current yielding not more than i cc. of electrolytic gas per minute. 
When the copper is all deposited draw ofif the liquid, wash the platinum 
cylinder, dry, and weigh. 

Determination of Invert Sugar in the Presence of Cane Sugar. — 
Meissl and Hiller Method.^ — Defecate 40 grams of the sample dissolved 
in 100 cc. of water in a 200-cc. graduated flask with a slight excess of normal 
lead acetate, make up to the mark, shake, filter, delead with dry sodium 
carbonate or sulphate and again filter. Place 5 cc. of alkaline copper 
solution in each of five test-tubes or small beakers, add i, 2, 3, 4, and 5 cc. 
of the sugar solution to form a series, heat each to boiling, boil 2 minutes, 
and filter. The solution which gives the highest shade of blue (not 
colorless) contains the proper proportion of sugars for the actual deter- 
mination. Pipette 20 times the volume used in the preliminary test into a 
loo-cc. graduated flask, make up to the mark and shake. Prepare 50 cc. 
of alkaline copper solution by mixing 25 cc. of each of the two solutions 
(page 615), heat to boiling, add 50 cc. of the sugar solution, heat again to 
boiling and boil for exactly 2 minutes. Filter and weigh as metallic copper, 
cuprous oxide, or cupric oxide and calculate the results using the following 
formulas and table as simplified by Rice : { 

,^ 100 Cu 88.82 CW2O 70.80 CuO looP 

I-=ioo-S, r = 0.02 YF, 

in which S and / = approximate per cents of sucrose and invert sugar in 
sugar solids, P = polarization of sample, Cu, CU2O, and CmO = weights 

* B. B. Ross, 8th Int. Cong. App. Chem., 8, 191 2, p. 75. 
t Zeits. Ver. deutsch. Zuker-Ind., 14, 1889, p. 715. 
X Personal communication. 



638 



FOOD INSPECTION AND ANALYSIS. 



of copper, cuprous oxide, and cupric oxide found, TF = weight of sample 
in ICO cc, i^ = factor found in following table, and /' = true per cent of 
invert sugar in the sample. 



MEISSL AND HILLER TABLE OF FACTORS FOR INVERT SUGAR 

DETERMINATION. 





Factors for Weights of Cu, CuiO, and CuO in Milligrams. 




Cu 


Cu 


Cu 


Cu 


Cu 


Cu 


Cu 




400 


350 


300 


250 


200 


150 


100 


S : I 


CU2O 


CuiO 


CU2O 


CuzO 


Cu'iO 


Cm20 


CmO 




450 


394 


338 


281 


225 


169 


113 




CuO 


CuO 


CuO 


CuO 


CuO 


CuO 


CuO 




500 


437 


375 


312 


250 


187 


125 


o : loo 


564 


55-4 


54-5 


53.8 


53-2 


530 


530 


lo : 90 


56.3 


55 


3 


54 


4 


53 


8 


53 


2 


52.9 


529 


20 : 80 


56.2 


55 


2 


54 


3 


53 


7 


53 


2 


52.7 


52.7 


30 : 70 


56.1 


55 


I 


54 


2 


53 


7 


53 


2 


52.6 


52.6 


40 : 60 


55-9 


55 





54 


I 


53 


6 


53 


I 


52.5 


52.4 


5° : 50 


55-7 


54 


9 


54 





53 


5 


53 


I 


52.3 


52.2 


60 : 40 


55-6 


54 


7 


53 


8 


53 


2 


52 


8 


52.1 


51-9 


70:30 


55-5 


54 


5 


53 


5 


52 


9 


52 


5 


519 


51.6 


80: 20 


55-4 


54 


3 


53 


3 


52 


7 


52 


2 


51-7 


513 


90 : 10 


54-6 


53 


6 


53 


I 


52 


6 


52 


I 


51-6 


52.2 


91 : 9 


54-1 


53 


6 


52 


6 


52 


I 


51 


6 


512 


50.7 


92 : 8 


53-6 


53 


I 


52 


I 


51 


6 


51 


2 


50.7 


50-3 


93 : 7 


53.6 


53 


I 


52 


I 


51 


2 


50 


7 


50.3 


49.8 


94 : 6 


531 


52 


6 


51 


6 


50 


7 


50 


3 


49-8 


48.9 


95 ' 5 


52.6 


52 


I 


51 


2 


50 


3 


49 


4 


48.9 


48.5 


96:4 


52.1 


51 


2 


50 


7 


49 


8 


48 


9 


47.7 


46.9 


97 : 3 


50-7 


50 


3 


49 


8 


48 


9 


47 


7 


46.2 


45-1 


98 : 2 


49.9 


48 


9 


48 


5 


47 


3 


45 


8 


43-3 


40.0 


99 : I 


47-7 


47 


3 


46 


5 


45 


I 


43 


3 


41.2 


38.1 



Rice's Expanded Meissl and Hiller Table * given on pages 639 to 641 
greatly facilitates the calculation of invert sugar as it gives percentages 
corresponding to different weights of copper, cuprous oxide, and cupric 
oxide, different amounts of the sample, and different polarizations. Instead 
of the amounts directed by Meissl and Hiller use for the preliminary tests 
0.25, 0.50, 1.25, 2.50, and 5 cc. These amounts multiplied by 20 represent 
I, 2, 5, 10, and 20 grams of the sample per 100 cc. Rice states, however, 
that he makes no preliminary tests; if the quantity used is too much he 



8th Int. Cong. App. Chem., 8, 191 2, p. 47. 



SUGAR AND SACCHARINE PRODUCTS. 



639 



RICE'S EXPANDED MEISSL AND HILLER TABLE GIVING PERCENTAGES OF 

INVERT SUGAR. 



Wt. of Sample in loo cc. 



Polarization. 



Wt. Obtained as 



Cu 



CuaO 



CuO 



0.0999 0.II2S|0. 1250 
O.IOI90.11471OI275 
0.10390.1170I0.1300 
0. 1059 O.1192 0.1325 
0.10700.12150.1350 
0.10990.12370.137s 
0.III9 0.1260 0.1400 
0.11380.12820.1425 
O.I158 0.1305 0.1450 
0.11780.13270,1475 
O.I198 0.1350 0.1500 



I Gram. 



0. 1462 

0.148s 
0.1507 

0.1530 



0.1525 
0.1550 
0.1575 
o. 1600 
o. 1625 
1650 
0.167s 
o. 1700 

0.ISS2I0.I725 



0.157s 

O.IS97 



0.12180.1372 

0.12380. 1395 

0.12580.1417 

0.1278 0.1440 

0.1298 

0.1318 

0.1338 

0.1358 

0.1378 

0.1398 

0.1418 

o.i438'o. 1620 
0.1458 0.1642 
0.147810. 1665 
0.1498 0.1687 
0.15180.1710 
0.1538 0.1732 
0.15580.1755 
0.15780. 1777 
0.15980.1800 
0.1618 0.1822 
0.1638 0.1845 
0.165810. 1867 
0.1678 o.i" 



2 Grams. 



O.1718 
0.1738 
0.1758 
0.1778 
0.1798 
0.1817 
0.1837 



0.1912 
0.1935 
0.1957 
0.1980 
. 2002 
o. 2025 

2047 
2070 



1750 
O.I77S 
1800 
1825 
0.1850 
0.1875 
0.1900 
1925 
1950 
1975 
2000 
2025! 
2050 
2075 
.2100 
.2125 
.2150 

.2175 
. 2200 
.2225 
.2250 
0.2275 
o . 2300 



10.28 
10.48 
10.69 
10.89 
II. 10 

11.3^ 
11.52 

"•73 
11.94 
12.15 
12.36 

12.57 

12.78 

12.99 

13.21 

13-42 

13-64 

13-85 

14.07 

14.28 

14-50 

14.72 

U-93 

15-15 

15-37 

15-59 

15-81 

16.03 

16.25 

16.47 

16.69 

16.91 

17-13 

17-35 

T7-S7 

17.79 

18.01 

18.23 

18.45 
18.67 



19. II 
19-34 



xo. 26 
10.46 
10.67 

10.87 
11.08 

11.29 
11.50 
II. 71 
11.92 
12.13 
12.34 

12.55 
12.76 
12.97 
13-19 
13-40 
13.62 

13-831 

14 05 

14. 26 

14.48 

14.69 

14.91 

15.12 

15-34 

15-56 

15-78 

16.00 

16.22 

16.44 

16.66 

16.88 

17.10 

17.32 

17-54 

17.76 

17.98 

18.20 

18.42 

18.64 

I 

19.08 

19.30 



5 Grams. 



85° 



S-I3 

5-24 

5-34 

5-44 

5-54 

5-65 

5 -76 

5- 

5-96 

6.07 

6.18 

6.28 

6.38 

6.49 

6.60 

6.70 

6.81 

6.92 

7-03 

7.13 

7.24 

7-35 
7.46 

7-56 
7-67 
7-78 
7-89 
7-99 
8.10 
8.21 
8.32 
8.43 
8.54 
8.65 
8.76 
8.87 



9.09 
9.20 
9 31 
9-42 
9-53 
9.64 



5-12 

5-23 

5-33 

5-43 

5 -S3 

5-63 

5-74 

5-84 

5-95 

6.05 

6.16 

6.26 

6.36 

6.47 

6.58 

6.68 

6.79 

6.90 

7.01 

7. II 

7.22 

7.33 

7-44 

7-54 

7-65 

7.76 

7-87 
7-97 
8.08 
8.19 
8.30 
8.40 
8.51 
8.62 
8.73 
8.83 
8.94 
905 
9.16 
9.26 
9-37 
9-48 
9-59 



10 Grams. 



20 Grams 



85° 



1. 661 
1.708 

1-755 

1.802 

I . 

1.896 

1.942 

1.989 

2.036 

2.082 

2.128 

2-175 
2.221 
2 .267 
2-3^3 

2-359 

2-405 
2.451 

2-4971 

2.543 
2.589 
2-635 
2.680 

2.726 
2.772 

2.817 
2.862 

2.907 

2-952 
2.997 
3.042 
3-087 
3-132 
3-177 

3-221 

3.266 

3-310 

3-354 
3-398 
3-433 
3-488 
3-532 
3-576 



1 .600 



1.696 

1-744 
1.792 

1-839 
1.886 

1-933 
1 .980 
2.027 
2.074 
2. 121 
2.168 
2.215 
2.262 
. 2 . 309 
2-356 
2.403 
2.449 



2.543 
2.589 
2.63s 
2.682 
2.728 

2.774 
2.820 
2.867 
2.913 

2.959 
3-005 
3-051 
3-097 
3-143 
3.188 

3-234 
3.280 

3-325 
3 370 
3-416 
3-461 
3-506 
3-551 



0.76 
0.78 
0.80 
0.82 
0.84 



85° 



0.90 
0.92 
0.94 
0.96 



1 .00 
1 .02 

I -OS 
1 .07 
1 .09 
I . II 
I -13 
1-15 
1. 17 
1. 19 
1 .22 
1 . 24 
1 .27 
1 . 29 
1-31 
1-33 
1-35 
1-37 
1 .40 
1.42 
1.44 
1.46 
1-49 
I-51 
1-53 
I-S5 
i-S8 
1 .60 
1 .62 
1.64 
1.67 



0.76 
0.78 
0.80 
0.82 
0.84 



0.90 
0.92 

0.94 
0.96 
0.98 
1. 00 
1 .02 
1 .04 
1 .06 



1. 10 
1. 12 
1. 14 
1. 16 
1. 18 
1 .21 

1-23 
1.25 
1.27 
1.30 
1.32 

1-34 
1.36 
1.38 
1.40 
1.42 
1.44 
1-47 
1-49 
I-51 
1-53 
1.56 
1.58 
1.60 
1.62 
1.6s 



0.72 
0.73 
0.75 
0.76 

•0.77 
0.78 

0.79 



640 



FOOD INSPECTION AND ANALYSIS. 



RICE'S EXPANDED MEISSL AND HILLER TABLE GIVING PERCENTAGES OF 
INVERT SUGAR— Continued. 



Wt. of Sample in loo cc. 


I Gram. 


2 Grams. 


5 Grams. 


ID Grams. 


20 Grams. 


Polarization. 


30° 


35° 


20° 


30° 


85° 


95° 


bS° 


95° 


85° 


95° 


Wt. Obtained as 


19.56 




















Cu 


CU2O 


CuO 




0.1857c 


3.2092 ( 


3.2325 


19.52 


9-75 


9.70 


3.621 


3-597 


1.69 


1.67 


0.80 




0.187710. 2II5'( 


3-2350 


19.78 


19-74 


9.86 


9.81 


3.666 


3.642 


I. 71 


1.69 


0.8I 




0. 1897 0.2137 


3-2375 


20.00 


19.96 


9-97 


9-92 


3.710 


3.687 


1-73 


1.72 


0.82 


0.81 


0. 1917 0.2160 


3.2400 


20.23 


20.19 


10.08 


10.03 


3-754 


3-732 


1.76 


1-75 


0.83 


0.83 


01937 


3.2182 


3.2425 


20.45 


20.41 


10.19 


10.14 


3-799 


3-777 


1.78 


1-77 


0.84 


0.84 


0-1957 


3.2205 


3.2450 


20.67 


20.63 


10.30 


10.25 


3 844 


3.822 


1.80 


1-79 


0.85 


0.85 


0.1977 


3.2227 


3-2475 


20.89 


20.85 


10.41 


10.36 


3.888 


3-867 


1.83 


1.81 


0.86 


0.86 


0. 1997 0.2250] 


0.2500 


21.12 


21.08 


10.52 


10.47 


2.932 


3.912 


1.86 


1.84 


0.88 


0.87 


0.2017 


0.2272 


0-2525 


21-34 


21.30 


10.63 


10.58 


3.977 


3-957 


1.88 


1.86 


0.89 


0.88 


0.2037 


0.2295 


0.2550 


21.56 


21.52 


10.74 


10.69 


4.. 02 2 


4.002 


1.90 


1.88 


0.90 


0.89 


0.2057 


0.2317 


^■2S75 


21.78 


21.74 


10.85 


10.80 


4.066 


4.047 


1.92 


1.90 


0.91 


0.90 


0.2077 


0.2340 


0.2600 


22.00 


21 .96 


10.96 


10.91 


4.110 


4.092 


1-95 


I 93 


0.92 


0.91 


0. 2097 


0.2362 


0.2625 


22.22 


22.18 


II .07 


11.02 


4.155 


4.137 


1-97 


1-95 


0.93 


0.92 


0.2117 


0.2385 


0.2650 


22.44 


22.40 


II. 18 


II. 13 


4. 200 


4.182 


1-99 


1-97 


0.94 


0-93 


0.2137 


0.2407 


0.2675 


22.66 


22.62 


11.29 


11.24 


4.244 


4-227 


2.02 


1.99 


0.95 


0.94 


0.2157 


0.2430 


0.2700 


22.89 


22.85 


II .40 


11-35 


4.288 


4.271 


2.05 


2.02 


0.97 


0.96 


0.2177 


0-2452 


0.2725 


23.11 


23.07 


II. 51 


11.46 


4-333 


4-316 


2.07 


2.04 


0.98 


0.97 


0.2197 


0-2475 


0.2750 


23 -33 


23-29 


11.62 


11-57 


4-378 


4-361 


2.09 


2.06 


0.99 


0.98 


0.2217 


0.2497 


0.2775 


23-55 


23-51 


"•73 


11.68 


4-422 


4-405 


2. II 


2.08 


1.00 


0.99 


0.2237 


0.2520 


0.2800 


23.78 


23 -74 


11.84 


11.79 


4.466 


4-449 


2.14 


2.12 


1. 01 


1.00 


0.2257 


0.2542 


0.2825 


24.00 


23.96 


11-95 


11.90 


4-511 


4-494 


2.16 


2.14 


1.02 


I.Ol 


0.2277 


0.2565 


0.2850 


.24.22 


24.18 


12.06 


12.01 


4-556 


4-538 


2.18 


2.16 


1.03 


1.02 


0.2297 


0.2587 


0.2875 


24.44 


24.40 


12.17 


12.12 


4.600 


4-582 


2.20 


2.18 


1.04 


1.03 


0.2317 


0.2610 


0. 2900 


24.67 


24.63 


12.28 


12.23 


4.644 


4.626 


2.23 


2.21 


1.06 


1-05 


0-2337 


0.2633 


0.2925 


24.89 


24-85 


12.39 


12.34 


4.689 


4-671 


2.25 


2.23 


1.07 


1.06 


0-2357 


0-2655 


0.2950 


25.11 


25-07 


12.50 


12.45 


4.734 


4.716 


2.27 


2.25 


1.08 


1.07 


0.2377 


0.2677 


0.2975 


25-33 


25-29 


12.61 


12.56 


4-779 


4.761 


2.29 


2.27 


1.09 


1.08 


0.2397 


0.2700 


. 3000 


25 56 


25-52 


12.73 


12.67 


4-823 


4.805 


2.32 


2.30 


1. 10 


1.09 


0.2417 


0.2722 


0.3025 


25-78 


25-74 


12.84 


12.78 


4.868 


4.850 


2-34 


2.32 


1. 11 


l.IO 


0.2437 


0-2745 


0.3050 


26.00 


25.96 


12.95 


12.89 


4-913 


4-895 


2.36 


2.34 


1.12 


1. 11 


0-2457 


0.2767 


0.3075 


26.22 


26.18 


13.06 


13.00 


4-958 


4.940 


2.39 


2-37 


I -13 


1.12 


0.2477 


0.2790 


0.3100 


26.45 


26.41 


13.18 


13-11 


5-003 


4 985 


2.42 


2.40 


I-I5 


1.14 


0.2497 


0.2812 


0.3125 


26.67 


26.63 


13.29 


13.22 


5 049 


5.031 


2.44 


2.42 


1.16 


I-I5 


0.2517 


0.2835 


0.3150 


26.90 


26.85 


13-40 


^3-33 


5-095 


5.076 


2.46 


2.44 


1. 17 


1.16 


02537 


0.2857 


3175 


27.12 


27.07 


13-51 


13.44 


5-141 


5.121 


2.48 


2.46 


1.18 


1.17 


0.2556 


0.2880 


. 3 200 


27-35 


27.30 


13-63 


13.56 


5-186 


5-166 


2.51 


2-49 


1.19 


I. 18 


0.2576 


0.2902 


0.3225 


27-57 


27-52 


13-74 


13.67 


4-232 


5-212 


2-53 


2-51 


1 .20 


I. 19 


0.2596 


0.2925 


0.3250 


27.80 


27-75 


13-85 


13.78 


5-278 


5-258 


2-55 


2-53 


1.21 


I .20 


0.2616 


0.2947 


0.3275 


28.02 


27.97 


13.96 


13.89 


5-324 


5 303 


2-57 


2-55 


1.22 


I . 21 


0.2636 


0.2970 


0.3300 


28.25 


28.20 


14.08 


14.01 


5.371 


5 348 


2.60 


2.58 


1.24 


1.23 


0.2656 


0. 2992 


0.3325 


28.47 


28.42 


14.19 


14.12 


5.418 


5-394 


2.62 


2.60 


1.25 


1.24 


0.2676 


0.3015 


0.3350 


28.70 


28.65 


14-30 


14.23 


5.465 


5 440 


2.64 


2.62 


1.26 


1.25 


0.2696 


0.3037 


3375 


28.93 


28.87 


14.42 


14.35 


5-512 


5.486 


2.66 


2.64 


1.27 


1.26 



SUGAR AND SACCHARINE PRODUCTS. 



641 



RICE'S EXPANDED MEISSL AND HILLER TABLE GIVING PERCENTAGES OF 
INVERT SUGAR— CoMc/M(/e(/. 



Wt. of Sample in loo cc. 


I Gram. 


2 Grams. 


5 Grams. 


10 Grams. 


20 Grams. 


Polarization. 


30° 


35° 


20° 


30° 


85° 


95° 


95° 


8s° 


85° 


95° 


Wt. Obtained as 






















Cu 


CujO 


CuO 




0.2716 


. 3060 


0.3400 


29.16 


29. 10 


14 -54 


14.47 


5 558 


5-532 


2.69 


2.67 


1.28 


1.27 


0.2736 


0.3082 


0.3425 


29 


39 


29 


32 


14 


65 


14. 


59 


I .605 


5 578 


2 


71 


2 


69 


1.29 


1.28 


0.2756 


0.3105 


0.3450 


29 


62 


29 


55 


14 


76 


14 


70 


5.652 


5.624 


2 


73 


2 


71 


1.30 


1.29 


0.2776 


0.3127 


0.3475 


29 


85 


29 


77 


14 


88 


14 


81 


5.699 


5.671 


2 


75 


2 


73 


131 


1.30 


0.2796 


0.3150 


0.3500 


30 


08 


30 


00 


15 


00 


14 


93 


5.746 


5. 718 


2 


78 


2 


76 


1-33 


1.32 


0.2816 


0.3172 


0.3525 


30 


31 


20 


23 


15 


II 


IS 


04 


5.793 


5.765 


2 


80 


2 


78 


1.34 


I 33 


0.2836 


0.3195 


0.3550 


30 


54 


30 


46 


15 


22 


IS 


15 


5.840 


5.812 


2 


82 


2 


80 


1.35 


1.34 


0.2856 


0.3217 


0.3575 


30 


77 


30 


69 


15 


34 


IS 


27 


5.888 


5.859 


2 


84 


2 


82 


1.36 


1-35 


0.2876 


0.3240 


0.3600 


31 


00 


30 


93 


15 


46 


IS 


39 


5. 936 


5.906 


2 


87 


2 


85 


1-37 


1.36 


0.28960.3262 


0.3625 


31 


23 


31 


16 


15 


57 


15 


50 


5 983 


5. 953 


2 


89 


2 


87 


1.38 


I 37 


0.2916 0.3285 


0.3650 


31 


46 


31 


40 


15 


69 


15 


61 


6.031 


6.000 


2 


91 


2 


88 


1.39 


1.38 


0.2936 


0.33070.3675 


31 


69 


31 


63 


15 


81 


15 


73 


6.079 


6.048 


2 


93 


2 


91 


1.40 


1-39 


0.2956 


0. 3330,0. 3700 


31 


93 


31 


87 


15 


93 


15 


85 


6.127 


6.096 


2 


96 


2 


94 


1.42 


1. 41 


0.2976 


0.33520.3725 


32 


16 


32 


10 


16 


04 


15 


96 


6.174 


6.144 


2 


98 


2 


96 


1-43 


1.42 


0.2996 


o.3375j0.375o 


32 


40 


32 


34 


16 


16 


16 


08 


6.222 


6.192 


3 


00 


2 


98 


1-44 


1.43 


0.3016 


0.33970.3775 


32 


63 


32 


67 


16 


28 


16 


20 


6.270 


6.240 


3 


03 


3 


00 


1-45 


1.44 


0.3036 


0.3420,0.3800 


32 


87 


32 


81 


16 


40 


16 


32 


6.318 


6.288 


3 


06 


3 


03 


1.46 


1.45 


0.3056 


0.34420.3825 


33 


10 


33 


04 


16 


52 


16 


44 


6.366 


6.337 


3 


08 


3 


05 


1-47 


1.47 


0.3076 


0.3465,0.3850 


33 


34 


33 


28 


16 


64 


16 


56 


6.414 


6.386 


3 


10 


3 


07 


1.48 


1.48 


0.3096 


0.3487 


0.387s 


33 


58 


33 


52 


16 


76 


16 


68 


6.462 


6.434 


3 


12 


3 


09 


1-49 


1.49 


O.3116 


0.3510 


. 3900 


33 


82 


33 


76 


16 


88 


16 


80 


6.510 


6.482 


3 


15 


3 


12 


i-Si 


i-So 


0.3136 


0.3532 


0.3925 


34 


06 


34 


00 


17 


00 


16 


92 


6.558 


6.531 


3 


17 


3 


14 


1.52 


I 51 


0.3156 


0.3555 


0.3950 


34 


30 


34 


24 


17 


12 


17 


04 


6.608 


6.580 


3 


19 


3 


16 


1.53 


1.52 


0.3176 


0.3577 


0.397s 


34 


54 


34 


48 


17 


24 


17 


16 


6.654 


6.629 


3 


21 


3 


18 


1.54 


1.53 


0.3196 


0.3600 


. 4000 


34 


78 


34 


72 


17 


36 


17 


28 


6.703 


6.678 


3 


24 


3 


21 


1.5s 


1.54 


0.3216 


0.3622 


0.4025 


35 


02 


34 


96 


17 


48 


17 


40 


6.751 


6.727 


3 


26 


3 


23 


1.56 


1-55 


0.3236 


0.3645 


0.4050 


35 


26 


35 


20 


17 


60 


17 


52 


6.799 


6.776 


3 


28 


3 


26 


1.57 


1.56 


0.3256 


0.3667 


0.4075 


35 


50 


35 


44 


17 


72 


17 


64 


6.848 


6.82s 


3 


30 


3 


27 


1.58 


1.57 


0.3275 


0.3890 


0.4100 


35 


75 


35 


68 


17 


84 


17 


76 


6.897 


6.875 


3 


33 


3 


30 


1.60 


1.59 


0.3295 


0.3712 


0.4125 


35 


99 


35 


92 


17 


96 


17 


88 


6.945 


6.924 


3 


35 


3 


32 


1.61 


1.60 


0.3315 


0.3735 


0.4150 


36 


24 


36 


16 


18 


08 


18 


00 


6.993 


6.973 


3 


37 


3 


34 


1.62 


1.60 


0.3335 


0.3757 


0.4175 


36 


48 


36 


40 


18 


20 


18 


12 


7.042 


7.023 


3 


39 


3 


36 


1.63 


1.62 


0.33550.37800 4200 


36 


73 


36 


65 


18 


33 


18 


25 


7.091 


7.073 


3 


42 


3 


39 


1.64 


1.63 


0.3375 


o.38o2|0.4225 


36 


97 


36 


89 


18 


45 


18 


37 


7-139 


7.122 


3 


44 


3 


41 


1.65 


1.64 


0.3395 


0.38250.4250 


37 


22 


37 


13 


18 


57 


18 


49 


7.188 


7.172 


3 


46 


3 


43 


1.66 


1.6s 


0.3415 


0.38470 4275 


37 


47 


37 


37 


18 


69 


18 


61 


7 237 


7.222 


3 


48 


3 


45 


1.67 


1.66 


0.3435 


0.38700.4300 


37 


.72 


37 


62 


18 


82 


18 


■74 


7.286 


7.272 


3 


51 


3 


48 


1.69 


1.68 


0.345s 


0.38920 4325 


37 


.96 


37 


86 


18 


94 


18 


.86 


7.334 


7.321 


3 


■53 


3 


50 


1.70 


1.69 


0.3475 


0.39150 4350 


38 


.21 


38 


10 


19 


06 


18 


.99 


7.383 


7.371 


3 


■55 


3 


52 


1.71 


1.70 


0.3495 


0.3937 


0.4375 


38 


.46 


38 


44 


19 


.19 


19 


.12 


7432 


7.421 


3 58 


355 


1.72 


1. 71 



642 FOOD INSPECTION AND ANALYSIS. 

starts with another portion of half the dilution. Full details of the process 
as now conducted follow : * 

" Weigh out a quantity which from the direct polarization seems proper, 
always estimating low. Dissolve and make up to mark and if not clear 
pour onto a filter paper in which has been placed a level teaspoonful of dry 
kieselguhr. Pour back until the filtrate comes clear. Place 50 cc. of the 
solution and 50 cc. of mixed alkaline copper solution in a 350-cc. Grifhn 
beaker and cover with clock glass. Heat on a piece of sheet asbestos, 
with a hole 5 cm. in diameter below which is a wire gauze, so as to reach 
boiling in 4 minutes or under 5 minutes. Boil exactly 2 minutes, then 
pour in 100 cc. of cold water. Remove from the flame immediately, filter 
through an ignited weighed porcelain Gooch crucible containing a layer of 
asbestos 3 mm. thick, previously treated for days with strong hydrochloric 
acid and alkaline copper solution. Heat ^ hour at dull redness, cool, and 
weigh as CuO." 

Determination of Sucrose by Fehling's Solution.t — If a polariscope is 
not available, cane sugar can be determined as follows: First determine the 
percentage of invert sugar present in the sample by one of the Fehling 
methods already described. Then dissolve i gram of the sugar in about 
100 cc. of water in a 500-cc. graduated flask, add 3 cc. of concentrated 
hydrochloric acid and invert by heating in water to 68° and cooling in the 
regular manner. Neutralize with sodium hydroxide or sodium carbonate, 
and make up to the mark with water. Determine the per cent of total 
reducing sugar as invert sugar either by the volumetric or gravimetric 
Fehling process. Subtract the invert sugar found present in the sugar by 
d'rect determination from the total found present after inversion, and 
the remainder is the invert sugar due to cane sugar. This figure multi- 
plied by 0.95 gives the percentage of cane sugar. 

For the determination of sucrose by the gravimetric Fehling process on 
the inverted sample, multiply the cupric oxide (CuO) by the factor 0.4307, 
or the copper (Cu) by the factor 0.5394. 

ANALYSIS OF MOLASSES AND SYRUPS. 

First insure a perfectly homogeneous sample by stirring with a rod 
to evenly distribute any separated sugar. 



* Personal communication. 

t Tucker, Manual of Sugar Analysis, p. 182. 



1 



SUGAR AND SACCHARINE PRODUCTS. 643 

Determination of Total Solids. — (i) Asbestos Method. — Weigh 20 
grams into a ico-cc. graduated flask, dissolve in water, and make up to 
the mark. Insure a uniform solution by shaking. Measure 10 cc. of 
this solution into a tared platinum dish containing about 5 grams of 
freshly ignited, finely divided asbestos fiber, and dry to constant v^eight 
at 70° in vacuo, or in a McGill oven (see page 609). 

(2) Sand Method. — Place a stirring rod in a flat-bottom metal dish, 
add ignited quartz sand sufficient to bring the total weight up to an even 
number of grams using not less than 12 to 15 grams, and weigh. Add 2 to 
4 grams of the material, dilute with water, and mix thoroughly. Dry 
on a water bath with stirring and finally in a water oven until the loss is 
insignificant. 

(3) By Calculation from Refractive Index. — Determine the refractive 
index by means of the Abb^ refractometer (page 94), and calculate the 
total solids, using Geerlig's tables (p. 645). 

This method is more accurate and convenient than the specific gravity 
method and employs a smaller quantity of material. The investigations 
of Stolle * and of Tolman and Smith f have shown that sucrose, maltose, 
dextrose, levulose and lactose all have practically the same refractive index. 
Dextrin has a somewhat' higher refractive index, nevertheless the solids 
of commercial glucose do not give a reading appreciably higher than 
the sugars named. 

A. H. Bryan J has compared this method with the method of drying 
at 70° in vacuo, with the following results : 

Number of Difference compared with 

Samples. the Gravimetric Method. 

Maple syrup 13 -1.3410+0.72 

Cane table syrup 10 —o. 79 to +0 . 62 

Cane molasses 17 — i . 53 to +0 . 59 

Beet molasses 15 —1.83 to —0.07 

Honey 24 —2.52 to +0.91 

Glucose 2 — o . 27 to +0 . 27 

(4) By Calculation from Specific Gravity. — Weigh 25 grams of the 
sample into a loo-cc. graduated flask, dissolve in water, and make up 



* Zeits. deutsch. Zucker-Ind., 1901, pp. 335, 469. 
t Jour. Am. Chem. Soc, 28, 1906, p. 1476. 
t Ibid., 30, 1908, p. 1443. 



644 FOOD INSPECTION AND ANALYSIS. 

20° 
to the mark. Determine the specific gravity, at —5 C, of the diluted 

solution by means of a pycnometer or accurate hydrometer. 

Ascertain from the table on pages 647 and 648 the percentage by 
weight of solids (sugar) corresponding to the specific gravity of the 
diluted solution, and calculate the total solids in the original sample by 
the following formula: 

in which S' is the total solids in original sample, D is the specific gravity 
of the diluted solution, and S is the per cent of solids in the diluted 
solution. 

The solids may also be obtained directly by means of the saccha- 
rometer, also known as the Brix spindle. This instrument is a hydrometer 
graduated so as the show the per cent of sugar when the temperature of 
the liquid is 20° C. 

If the specific gravity or saccharometer reading is taken at any other 
temperature than 20° C. the necessary correction may be found in the 
table on page 649. 

Determination of Ash. — Weigh from 5 to 10 grams of the sample 
into a tared platinum dish, evaporate to dryness on the water-bath, and 
proceed as directed for ash of sugar (page 609). 

Polarization and Determination of Sucrose. — Molasses and golden 
syrup require the application of clarifying reagents before a suflficiently 
clear solution can be obtained for reading on the polariscope. Even 
then it is not possible nor is it necessary to get a water-white solution, so 
that in this class of products greater accuracy can usually be attained by 
polarizing in a loo-mm. tube (half the standard length) and multiplying 
the reading by 2. In some cases it may be found necessary to use an 
even shorter tube. 

When the sample contains a considerable amount of glucose the use of 
the shorter tube is absolutely necessary since otherwise the range of the 
scale would not permit of a reading. 

The clarifier best adapted as a rule for molasses and golden syrup is 
lead subacetate either in the form of a solution as described on page 610, 
or, as first proposed by Home,* in the form of the anyhdrous salt. 

* Jour. Am. Chem. Soc, 26, 1904, p. 186. 



SUGAR AND SACCHARINE PRODUCTS. 



645 



GEERLIGS'S TABLE FOR DRY SUBSTANCE IN SUGAR-HOUSE PRODUCTS 
BY THE ABBE REFRACTOMETER, AT 28° C* 





Per 








Per 




Refrac- 


Cent 


Decimals to be Added for Re 


frac- 


Cent 


Decimals to be Added for 


tive 


Dry 


Fractional Readings, t 


tive 


Dry 


Fractional Readings t 


Index. 


Sub- 
stance. 




1 In 


dex. 


Sub- 
stance. 




1-3335 


I 


0.0001 = 0.05 


0.0010=0.75 I 


4083 


45 


0.0004 = 0.2 


0.0015 = 0.75 




3349 


2 


0.0002 = 0.1 


0.0011 = 0.8 I 


4104 


46 


0.0005 = 0.25 


0.0016 = 0.8 




3364 


3 


0.0003 = 0.2 


0.0012 = 0.8 I 


4124 


47 


0.0006 = 0.3 


0.0017 = 0.85 




3379 


4 


0.0004 = 0.25 


0.0013 = 0.85 I 


4145 


48 


0.0007 = 0.35 


0.0018 = 0.9 




3394 


5 


0.0005 = 0.3 


0.0014 = 0.9 I 


4166 


49 


0.0008 = 0.4 


0.0019=0.95 




3409 


6 


. 0006 = 0.4 


0.0015=1.0 I 


4186 


50 


0.0009 = 0.45 


0.0020= I.O 




3424 


7 


0.0007 = 0.5 




4207 


51 


0.0010 = 0.5 


0.0021 = 1.0 




3439 


8 


0.0008 = 0.6 




4228 


52 


0.0011 = 0.55 






3454 


9 


0.0009 = 0.7 




4219 


53 








3469 


ID 






4270 


54 








3484 


II 


0.0001 = 0.05 




4292 


55 


0.0001 = 0.05 


0.0013=0.55 




3500 


12 


0.0002 = 0.1 




4314 


56 


0.0002 = 0.1 


0.0014=0.6 




3516 


13 


0.0003 = 0.2 




4337 


57 


0.0003 = 0.1 


0.0015 = 0.65 




3530 


14 


0.0004 = 0.25 




4359 


58 


0.0004=0.15 


0.0016=0.7 




3546 


15 


0.0005 = 0.3 




4382 


59 


0.0005 = 0.2 


0.0017 = 0.75 




3562 


16 


0.0006=0.4 




4405 


60 


0.0006 = 0.25 


0.0018 = 0,8 




3578 


17 


0.0007 = 0.45 




4428 


61 


0.0007 = 0.3 


0.0019=0.85 




3594 


18 


0.0008=0.5 




4451 


62 


0.0008 = 0.35 


0.0020 = 0.9 




3611 


19 


0.0009=0.6 




4474 


63 


0.0009 = 0.4 


0.0021 =0.9 




3627 


20 


0.0010=0.65 




4497 


64 


0.0010=0.45 


0.0022 = 0.95 




3644 


21 


0.0011=0.7 




4520 


65 


0.0011 = 0.5 


0.0023= i-o 




3661 


22 


0.0012 = 0.75 




4543 


66 


0.0012 = 0.5 


0.0024=1.0 




3678 


23 


0.0013 = 0.8 




4567 


67 








3695 


24 


0014=0.85 




4591 


68 








3712 


25 


0.0015 = 0.9 




4615 


69 








3729 


26 


0.0016 = 0.95 




4639 


70 














4663 


71 














4687 


72 
















1-3746 


27 


0.0001 = 0.05 


0.0012 = 0.6 












3764 
3782 


28 


0.0002 = 0.1 
0.0003 = 0.15 


n no T "2 = 6 c - 












29 


0.0014 = 0.7 I 


4711 


73 


0.0001 = 0.0 


0.0015=0.55 




3800 


30 


0.0004=0.2 


0.0015 = 0.75 I 


4736 


74 


0.0002 = 0.05 


0.0016 = 0.6 




3818 


31 


0.0005 = 0.25 


0.0016 = 0.8 I 


4761 


75 


0.0003 = 0.1 


0.0017 = 0.65 




3836 


32 


. 0006 = 0.3 


0.0017 = 0.85 I 


4786 


76 


0.0004=0.15 


0.0018 = 0.65 




3854 


33 


0.0007 = 0.35 


0.0018 = 0.9 I 


4811 


77 


0.0005 = 0.2 


0.0019=0.7 




3872 


34 


0.0008 = 0.45 


0.0019=0.95 I 


4836 


78 


0.0006 = 0.2 


0.0020 = 0. 7J 




3890 


35 


0.0009 = 0.4 


0.0020=1.0 I 


4862 


79 


0.0007 = 0.25 


0.0021 = 0.8 




3909 


36 


0.0010=0.5 


0.0021 = 1.0 I 


4888 


80 


. 0008 = 0.3 


0.0022 = 0.8 




3928 


37 


0.0011 = 0.55 




4914 


81 


0.0009=0.35 


0.0023 = 0.85 




3947 


38 






4940 


82 


0.0010 = 0.35 


0.0024 = 0.9 




3966 


39 






4966 


83 


0.0011 = 0.4 


0.0025 = 0.9 




3984 


40 






4992 


84 


0.0012 = 0.45 


0.0026 = 0.95 




4003 


41 






5019 


85 


0.0013 = 0.5 


0.0027 = 1.0 










5046 


86 

87 


0014 = 0.5 


0.0028=1.0 










5073 






1.4023 


42 


0.0001 = 0.05 


0.0012 = 0.6 I 


5100 


88 






1.4043 


43 


0.0002 = 0.1 


0.0013 = 0.65 I 


5127 


89 






1.4063 


44 


0.0003 = 0.15 


0.0014=0.7 I 


5155 


90 







* Intern. Sugar Jour., lo, pp. 69-70. 

t Find in the table the refractive index which is next lower than the reading actually mada 
and note the corresponding whole number for the per cent of dry substance. Subtract the refractive 
index obtained from the table from the observed reading; the decimal corresponding to this 
difference, as given in the column so marked, is added to the whole per cent of dry substance as 
first obtained. 



646 



FOOD INSPECTION AND ANALYSIS. 



TEMPERATURE 


CORRECTIONS 


FOR 


USE 


WITH GEERLIGS'S 


TABLE. 


Tempera- 


Dry Substance. 


ture of the 
Prisms in 


1 5 


10 1 li^ 1 20 


25 1 30 1 40 1 50 1 60 1 70 


80 j 90 


°C. 


Subtract — 


20 


0-53 


0.54 


0-5S 


0.56 


0-57 


0.58 


0.60 


0.62 


0.64 


0.62 


0.61 


0.60 


0.58 


21 


.46 


■47 


.48 


-49 


-50 


•51 


.52 


-54 


-56 


-54 


-53 


-52 


-50 


22 


.40 


.41 


-42 


-42 


-43 


.44 


-45 


-47 


.48 


-47 


.45 


-45 


-44 


23 


-33 


-33 


-34 


-35 


•3<> 


-37 


-38 


-39 


.40 


-39 


-38 


-38 


-38 


24 


.26 


.20 


.27 


.28 


.28 


.29 


-30 


-31 


•32 


•31 


•31 


-30 


■30 


^s 


.20 


.20 


.21 


.21 


.22 


.22 


•23 


•23 


-24 


•23 


-23 


-23 


.22 


26 


.12 


.12 


-13 


-14 


-14 


-15 


-15 


.16 


.16 


.16 


■ 15 


■IS 


.14 


27 


.07 


.07 


.07 


.07 


.07 


.07 


.08 


.08 


.08 


.08 


.08 


.08 


.07 




Add— 


29 


0.07 


0.07 


0.07 


0.07 


0.07 


0.07 


0.08 


0.08 


0.08 


0.08 


0.08 


0.08 


0.07 


30 


.12 


.12 


-13 


.14 


.14 


.14 


-15 


-15 


.16 


.15 


.16 


-15 


■14 


31 


.20 


.20 


.21 


.21 


.22 


.22 


•23 


■23 


-24 


.23 


■23 


-23 


.22 


32 


.26 


.2b 


.27 


.28 


.28 


•29 


-30 


-31 


-32 


-31 


■31 


-30 


-30 


33 


•33 


■33 


-34 


-35 


-3b 


•37 


-38 


-39 


.40 


■39 


.38 


■38 


■38 


34 


.40 


-41 


-42 


.42 


-43 


• 44 


-45 


■47 


■ 48 


■47 


.4b 


-45 


-44 


35 


.40 


-47 


.48 


-49 


-50 


-51 


-52 


-=^4 


.r6 


.■^4 


.5^ 


.t;2 


■ ,^0 



The Process. — The normal weight, 26 grams, of the molasses or s}Tup 
is dissolved in water in a loo-cc. flask, and in the case of molasses and 
"golden," or "drip" syrup, sufficient subacetate of lead solution is added 
^.o precipitate the coloring matter. From 5 to 10 cc. of the clarifier 
usually suffice. The flask is then filled to the mark with water and the 
contents shaken thoroughly and filtered. If on account of air bubbles 
it is difficult to make up to the mark, the bubbles may usually be dis- 
pelled by a drop of ether. With maple syrup no clarifier is, as a rule, 
necessary, though sometimes alumina cream is helpful. With a very 
dark-colored molasses 20 to 30 cc. of lead subacetate are required for 
clarification and in extreme cases (though rarely with the grades of molasses 
used as food) it is necessary, after the ordinary filtration, to pass through 
from 5 to 6 grams of powdered, dried bone charcoal.* 

An excess of subacetate of lead should be avoided on account of the 
possibility of the filtrate becoming turbid through the formation of lead 
carbonate by exposure to the air. A drop of acetic acid will nearly always 
clear the solution, if the turbidity is due to carbonate. If cloudiness in 
the filtrate persists, weigh out a fresh portion of the sample, dilute, and 
add first the lead subacetate solution, and afterwards enough of a strong 
solution of sodium sulphate or common salt to precipitate the excess of 
lead; then fill to the mark and filter. Polarize, and conduct the inver- 
sion as directed on p. 610, using, however, a loo-mm. tube, and multi- 

* The treatment with bone char should be used only as a last resort, as, on account of 
slight absorption of sugar, observed readings are from 0.4° to to 0.5° too low. 



SUGAR AND SACCHARINE PRODUCTS. 



647 



DENSITY OF SOLUTIONS OF CANE SUGAR AT 



C* 



si 








Tenths of Per Cent. 






























(S 





I 


2 


3 


4 


5 


6 


7 


8 


9 





0.9982 


0. 9986 


0.9990 


0.9994 


0. 9998 


I . 0002 


1 .0006 


I .OOIO 


I -0013 


I .0017 


I 


I .0021 


I .0025 


I .0029 


I 0033 


I .0037 


1 .0041 


1 0045 


I .0048 


1 .0052 


I .0056 


2 


I .0060 


I .0064 


1 .0068 


I .0072 


I .0076 


1 .0080 


1 .0084 


1.0088 


1 .0091 


1.0095 


3 


I .0099 


I .0103 


I .0107 


1 .01 1 1 


I . 01 1 5 


I .01 19 


1. 0123 


I .0127 


I 0131 


I-013S 


4 


I. 0139 


I. 0143 


I-0147 


1.0151 


I-OI5S 


1 .0159 


I .0163 


I .0167 


1 .01 71 


1.017s 


5 


I. 0179 


1-0183 


I .0187 


I .0191 


I .0195 


I. 0199 


I .0203 


I .0207 


1 .021 1 


I -0215 


6 


I .0219 


I .0223 


I .0227 


1 -0231 


1.0235 


I .0239 


1 .0243 


1 .0247 


1.0251 


I -0255 


7 


I.02S9 


I .0263 


I .0267 


1 .0271 


1 .0276 


1.0279 


I .0283 


1.0287 


1 .0291 


1 -0295 


8 


I .0299 


1-0303 


I .0308 


I .0312 


I .0316 


I .0320 


1-0324 


1.0328 


1-0332 


1 -0336 


9 


I .0340 


1-0344 


1 0349 


I 0353 


I-03S7 


I .0361 


1-0365 


1.0369 


1-0373 


1-0377 


lO 


I. 0381 


1.0386 


I .0390 


I 0394 


1.0398 


I .0402 


1 .0406 


I .0410 


1.041S 


I. 0419 


1 1 


1.0423 


I .0427 


1 .0431 


I 0435 


1 .0440 


I .0444 


I .0448 


I .0452 


I .0456 


I .0460 


12 


I .0465 


I .0469 


1 .0473 


I .0477 


1 .0481 


I .0486 


I .0490 


1.0494 


I .0498 


I .0502 


13 


1.0507 


1.0511 


I .0515 


1 .0519 


1 -0524 


1-0528 


1-0532 


1-0536 


I .0540 


I-OS45 


14 


I -0549 


I-0553 


I 0558 


I .0562 


1 .0566 


1.0570 


1-0575 


I-OS79 


1.0583 


1-0587 


IS 


1.0592 


I .0596 


I .0600 


1 . 0605 


1 .0609 


1-0613 


I .0617 


I .0622 


I .0626 


I .0630 


i6 


1.063s 


I .0639 


I .0643 


I .0648 


I .0652 


I .0656 


I .0661 


I .0665 


1 .0669 


1.0674 


17 


1.0678 


I .0682 


I .0687 


I .0691 


I -0695 


I .0700 


I .0704 


I .0708 


1 -0713 


1. 0717 


i8 


I .0721 


I .0726 


I .0730 


1 -073s 


I-0739 


1 -0743 


I .0748 


I .8752 


1 -0757 


I .0761 


19 


1.0765 


1.0770 


I .0774 


I .0779 


1.0783 


1.0787 


I .0792 


1.0796 


I .0801 


1 .0805 


20 


I .0810 


I .0814 


I .0818 


1.0823 


I .0827 


1.0832 


1.0836 


1 .0841 


1-0845 


I .0850 


21 


I .0854 


I .0859 


1 .0863 


I .0868 


1 .0872 


1.0877 


1.0881 


1.0885 


I .0890 


I .0894 


22 


I .0899 


I .0904 


I .0908 


I -0913 


I .0917 


I .0922 


1 .0926 


I. 0931 


I -093s 


I .0940 


23 


1.0944 


1.0949 


I 0953 


1 -0958 


I .0962 


I .0967 


1 -0971 


I .0976 


1.0981 


1.098s 


24 


I .0990 


1.0994 


I .0999 


I . 1003 


I . 1008 


I .1013 


I . 101 7 


I . 1022 


1 . 1026 


I .1031 


25 


I. 1036 


I . 1040 


1.1045 


1 .1049 


I. 1054 


I. 1059 


I - 1063 


1.1068 


1 . 1072 


1. 1077 


26 


I . 1082 


I. 1086 


I . 1091 


I . 1096 


I . 1 100 


I . iios 


I . II 10 


I . 1 1 14 


1 . 1 119 


I . 1124 


27 


I .1128 


1.1133 


1 . 1138 


I . 1142 


I. 1147 


1.1152 


1.1156 


1 . 1161 


1 . 1166 


I . 1170 


28 


I.II7S 


I . 1 1 80 


1-1185 


I. II 89 


1.1194 


I 1199 


1. 1 203 


I .1208 


1 . 1213 


1.1218 


29 


I . 1222 


I . 1227 


I . 1232 


1.1237 


I . 1241 


I . 1246 


1 .1251 


I .1256 


I . 1260 


I . 1265 


3° 


I . 1270 


I.I27S 


1 .1279 


I .1284 


I .1289 


I .1294 


I. 1299 


I -1303 


1.1308 


I-1313 


31 


1. 131** 


1-1323 


1 -1327 


I -1332 


1-1337 


I .1342 


1-1347 


1-1351 


II3S6 


1.1361 


32 


1. 1366 


1-1371 


1.1376 


I. 1380 


I. 1385 


1.1390 


1.139s 


I . 1400 


I .1405 


I . 1410 


33 


1.1415 


1.1419 


I .1424 


I .1429 


I-1434 


I -1439 


I .1444 


I. 1449 


1.1454 


I-I4S9 


34 


I. 1463 


I . 1468 


1-1473 


I. 1478 


I -1483 


1.1488 


I. 1493 


1.1498 


I -1503 


I. 1508 


3S 


1.1513 


1.1518 


I -1523 


1.1528 


I-1S33 


I-1538 


1.1542 


I-IS47 


1-1552 


1. 1557 


36 


I. 1562 


1.1567 


1.1572 


1-1577 


1.1582 


I. 1587 


I .1592 


I -1597 


I . 1602 


I . 1607 


37 


I . 1612 


I . 161 7 


I . 1622 


1 . 1627 


I -1632 


1.1637 


I. 1643 


1.1648 


11653 


1.1658 


38 


I. 1663 


1.1668 


I .1673 


1. 1678 


I. 1683 


I. 1688 


I .1693 


1 .1698 


1-1703 


1.1708 


39 


1-1713 


1.1718 


I .1724 


I. 1729 


1-1734 


1-1739 


1-1744 


I-1749 


1-1754 


I.I7S9 


40 


I. 1764 


I .1770 


1-1775 


I .1780 


I. 1785 


1. 1 790 


I-I79S 


1 . 1800 


1. 1 806 


I.i8n 


41 


1.1816 


I .1821 


I .1826 


1.1831 


I. 183 7 


1.1842 


I-1847 


1.1852 


1-1857 


1.1863 


42 


I. 1868 


I. 1873 


1.1878 


I. 1883 


1.1889 


1.1894 


I . 1899 


I .1904 


1 . 1909 


1 -191S 


43 


I . 1920 


1-1925 


1.1930 


I .1936 


I -1941 


I. 1947 


I-I9SI 


I -1957 


I . 1962 


I. 1967 


44 


1. 1972 


1.1978 


I. 1983 


I. 1988 


I. 1994 


I 1999 


I . 2004 


I . 2009 


I .2015 


I . 2020 


45 


1.2025 


I . 2031 


I .2036 


I .2041 


1.2047 


I .2052 


I.20S7 


I .2063 


1.2068 


I .2073 


46 


1.2079 


I . 2084 


I . 2089 


1.2095 


I . 2100 


1 • 2105 


1.2111 


1.2116 


1.2122 


I .2127 


47 


I. 2132 


I. 2138 


I .2143 


I .2149 


1.2154 


1-2159 


I .2165 


1 . 2170 


I .2176 


I .2181 


48 


1. 2 1 86 


I . 2192 


I .2197 


I .2203 


I .2208 


I . 2214 


1.2219 


1 .2224 


I .2230 


1.2235 


49 


I .2241 


I . 2246 


I .2252 


1.2257 


I .2263 


1.2268 


I .2274 


1 .2279 


I .2285 


I . 2290 


50 


1 . 2296 


I. 2301 


1.2307 


1. 2312 


1.2318 


1-2323 


I .2329 


1-2334 


I .2340 


1-2345 



* According to Dr. F. Plato (Kaiserlichen Normal-Eichungs-Kommission, Wiss. Abh., 2, 1900, 
page 153). This table (carried out to the 6th place of decimals) is given by the U. S. Bureau of Stan- 
dards. (Circ. 44, pp. 137-139) as the basis for standardizing hydrometers, indicating per cent of sugar 
at 20°, known as saccharometers or Brix spindles. The table is also useful in calculating the per cent 
of sugar from the specific gravity as determined by the pycnometer. Temperature corrections are 
given on page 649. 



648 



FOOD INSPECTION AND ANALYSIS. 



DENSITY OF SOLUTIONS OF CANE SUGAR AT -3- C— Continued 

4 





Tenths of Per Cent. 


ft 





I 


2 


3 


4 


5 


6 


7 


8 


9 


50 


1 . 2296 


I .2301 


1.2307 


I .2312 


I. 2318 


1.2323 


1.2329 


1-2334 


1-2340 


I-234S 


SI 


1-2351 


1.2356 


I .2362 


1.2367 


1.2373 


1.2379 


1-2384 


1.2390 


1-2395 


I .2401 


52 


I . 2406 


r . 2412 


I . 2418 


I .2423 


I .2429 


1.2434 


I . 2440 


I . 2446 


1.2451 


1.2457 


53 


I . 2462 


1.2468 


1.2474 


1.2479 


1-2485 


I .2490 


I . 2496 


I . 2502 


1.2507 


1.2513 


54 


1-2519 


1.2524 


1-2530 


1.2536 


I. 2541 


1.2547 


I-2SS3 


1.2558 


1.2564 


1.2570 


55 


1-2575 


I. 2581 


1.2587 


I .2592 


1.2598 


I . 2604 


I . 2610 


I .2615 


I . 2621 


I . 2627 


56 


I . 2632 


1.2638 


I . 2644 


I .2650 


1.2655 


I .2661 


I .2667 


1.2673 


1.2678 


1.2684 


57 


I . 2690 


I .2696 


I . 2701 


1.2707 


I .2713 


1.2719 


1.272s 


1-2730 


I -2736 


1.2742 


58 


1.2748 


1-2754 


I-27S9 


1.276s 


I. 2771 


1.2777 


1.2783 


1.2788 


1.2794 


I . 2800 


59 


1.2806 


I . 2812 


I. 2818 


1.2823 


I .2829 


1.2835 


I. 2841 


1.2847 


1.2853 


I .2859 


60 


1.286s 


1.2870 


1.2876 


1.2882 


1.2888 


I .2894 


I . 2900 


I . 2906 


I . 2912 


I .2918 


61 


I . 2924 


I . 2929 


1.2935 


1.2941 


1.2947 


1.2953 


I -2959 


1.2965 


1-2971 


I -2977 


62 


I .2983 


I .2989 


1.2995 


I .3001 


I .3007 


I. 3013 


I. 3019 


1.302s 


1-3031 


1-3037 


63 


1-3043 


1-3049 


1.3055 


I .3061 


1-3067 


1.3073 


1-3079 


1.308s 


I-3091 


I -3097 


64 


1-3103 


I. 3109 


1.3115 


I .3121 


I-3127 


1-3133 


I. 3139 


I. 3145 


1. 3151 


1-3157 


65 


I-3163 


1. 3169 


1.317s 


I. 3182 


I. 3188 


I. 3194 


1.3200 


I .3206 


I .3212 


1.3218 


66 


I .3224 


I -323* 


1.3236 


1-3243 


1.3249 


1-3255 


I .3261 


I .3267 


1.3273 


1-3279 


67 


1.3286 


I .3292 


1.3298 


1-3304 


I. 3310 


1-3316 


1.3322 


1.3329 


1.3335 


I -3341 


68 


1-3347 


I-33S3 


1.3360 


1-3366 


1-3372 


1-3378 


1.3384 


1. 3391 


1.3397 


I -3403 


69 


1.3409 


I. 3416 


1.3422 


1.3428 


1.3434 


1.3440 


1.3447 


1.3453 


1. 3459 


1.346s 


70 


1.3472 


1-3478 


1.3484 


1-3491 


1.3497 


1.3503 


1-3509 


1.3516 


1.3522 


1-3528 


71 


1.3535 


I. 3541 


1.3547 


1.3553 


1.3560 


1.3566 


1-3572 


1.3579 


1-3585 


1-3591 


72 


1.3598 


I .3604 


I .3610 


I. 3617 


1-3623 


1.3630 


1.3636 


I .3642 


I -3649 


1-3655 


73 


I .3661 


1.3668 


1-3674 


I. 3681 


1.3687 


1.3693 


1.3700 


1.3706 


1-3713 


1-3719 


74 


1.3725 


1.3732 


1-3738 


1-3745 


1-3751 


I -3757 


1.3764 


1.3770 


1.3777 


1.3783 


75 


1-3790 


1-3796 


1.3803 


I .3809 


I. 3816 


1.3822 


1.3829 


1-3835 


1.3841 


1.3848 


76 


1.3854 


I. 3861 


1.3867 


1-3874 


1.3880 


1.3887 


1-3893 


I -3900 


1.3907 


1-3913 


77 


1.3920 


1.3926 


1.3933 


1-3939 


I -3946 


I-39S2 


I -3959 


1.3965 


1.3972 


1-3978 


78 


1.398s 


1.3992 
I ■405» 


1.3998 


I .4005 


I . 401 1 


I .4018 


1.4025 


1. 403 1 


1 .4038 


I . 4044 


79 


1.4051 


I .4064 


I. 4071 


I .4077 


I .4084 


I .4091 


1.4097 


I .4104 


I .4111 


80 


1.4117 


I. 4124 


I .4130 


1-4137 


I -4144 


1-4150 


I. 4157 


I .4164 


I. 4170 


I-4177 


81 


I. 4184 


I .4190 


I. 4197 


I .4204 


I . 4210 


I .4217 


1.4224 . 


I. 4231 


1.4237 


1.4244 


82 


1.4251 


I -4257 


I . 4264 


1-4271 


I .4278 


I . 4284 


I .4291 


I .4298 


I .4305 


I -4311 


83 


1. 43 1 8 


1-4325 


1.4332 


1.4338 


I -4345 


1-4352 


1.4359 


1.4365 


1-4372 


I -4379 


84 


1.4386 


1.4393 


1-4399 


I .4406 


I. 4413 


I .4420 


I .4427 


1.4433 


I -4440 


1 -4447 


8S 


1-4454 


I . 4461 


1 .4468 


1.4474 


I .4481 


I .4488 


I. 4495 


1.4502 


1-4509 


1-4515 


86 


1-4522 


I -4529 


1-4536 


1.4543 


1.4550 


I .4557 


1.4564 


1.4570 


1-4577 


I .4584 


87 


I. 4591 


I .4598 


I .4605 


I .4612 


I . 4619 


I .4626 


1.4633 


I .4640 


I . 4646 


1-4653 


88 


I . 4660 


I .4667 


I -4674 


I. 4681 


1.4688 


1.4695 


1.4702 


1.4709 


I. 4716 


1-4723 


89 


1.4730 


1-473 7 


1.4744 


1.4751 


1.4758 


1.476s 


1.4772 


1-4779 


1.4786 


1-4793 


90 


I .4800 


I . 4807 


I . 4814 


I .4821 


1.4828 


1.483s 


I .4842 


1.4849 


1.4856 


1-4863 


91 


I .4870 


1.4877 


1.4884 


I .4891 


1.4898 


I .4905 


I .4912 


1.4919 


I .4926 


1-4934 


92 


I. 4941 


1.4948 


I -4955 


I .4962 


1.4969 


I .4976 


1 -4983 


1.4990 


I .4997 


I .5004 


93 


I. 5012 


1.5019 


I .5026 


I 5033 


I . 5040 


I-S047 


1-5054 


I .5061 


1 .5069 


I -5076 


94 


I • 5083 


1.5090 


I -5097 


I .5104 


1.5112 


I .5119 


I .5126 


1.S133 


I .5140 


I-5147 


95 


I -SI 55 


I .5162 


I. 5169 


1.5176 


I-S183 


I-5191 


1.5198 


I-520S 


I .52x2 


1-5219 


96 


1-5227 


1.5234 


1-5241 


1.5248 


I-52S5 


1-5263 


1-5270 


1-5277 


1-5284 


1-5292 


97 


I -5299 


1.5306 


I -53 1 3 


1.5321 


1-5328 


i-53?5 


1-5342 


1-5350 


5-5357 


I -5364 


98 


1-5372 


1-5379 


1.5386 


1.5393 


I .5401 


I -5408 


I-5415 


1-5423 


1-5430 


1-5437 


99 


I -5445 


I-54S2 


I-S459 


1.5467 


1-5474 


I. 5481 


1-5489 


1-5496 


1-5503 


i-SSii 


100 


I . 5 5 1 8 





















SUGAR AND SACCHARINE PRODUCTS. 



649 



TEMPERATURE CORRECTIONS TO SACCHAROMETER READINGS 
(STANDARD AT 20° C.).* 





Observed Per Cent of Sugar. 






Tempera- 
ture in 
Degrees 
Centigrade. 





5 


10 


15 


20 


25 


30 


35 


40 


45 


50 


55 


60 


70 
















































Subtract from Observed Per Cent. 






o 


0.30 


0.49 


0.6s 


0.77 


0.89 


0.99 


1.08 


1. 16 


1.24 


1. 31 


1-37 


1. 41 


1.44 


1.49 


5 


0.36 


0.47 


0.56 


0.65 


0.73 


o.8d 


0.86 


0.91 


0.97 


1. 01 


I. OS 


1.08 


1 . 10 


1. 14 


lo 
II 

12 

13 

14 


0.32 
0.31 
0.29 
0.26 
0.24 


0.38 
0.35 
0.32 
0. 29 
0.26 


0.43 
0.40 
0.36 
0.32 
0.29 


0.48 
0.44 
0.40 
0.35 
0.31 


0.52 
0.48 
0.43 
0.38 
0.34 


0.57 
0.51 
0.46 
0.41 
0.36 


0.60 
0.55 
0.50 
0.44 
0.38 


0.64 
0.58 

0.52 

0.46 
0.40 


0.67 
0.60 

0.54 
0.48 
0.41 


0.70 
0.63 
0.56 
0.49 
0.42 


0.72 
0.65 
0.58 
0.51 
0.44 


0.74 
0.66 
0.59 
0.52 
0.45 


0.75 
0.68 
0.60 
0.53 
0.46 


0.77 
0.70 
0.62 

O.S5 
0.47 


IS 
l6 
17 
l8 
19 


0.20 
0.17 
0.13 
0.09 
0.05 


0.22 
0.18 
0.14 
0. 10 
0.05 


0.24 
0.20 
0.15 

0. ID 

0.05 


0.26 
0.22 
0. 16 

O.II 

0.06 


0.28 
0.23 
0.18 
0.12 
0.06 


0.30 

0.25 

0. 19 
0.13 
0.06 


0.32 
0.26 
0.20 
0.13 
0.07 


0.33 
0.27 
0. 20 
0.14 
0.07 


0.34 
0.28 
0.21 
0. 14 
0.07 


0.36 
0.28 
0, 21 
0.14 
0.07 


0.36 
0.29 
0.22 
O.IS 
0.08 


0.37 
0.30 
0.23 
0.15 
0.08 


0.38 

;.3i 
0.23 
0.15 
0.08 


0.39 
0.32 
0. 24 
0.16 
0.08 


17.5 


O.II 


0. 12 


0. 12 


0. 14 


o.is 


0. 16 


0.16 


0.17 


0.17 


0.18 


0.18 


0.19 


0.19 


0. 20 


15 36 
(6o° F.) 


0.18 


0.20 


0.22 


0.24 


0.26 


0.28 


0.29 


0.30 


0.30 


0.32 


0.33 


0.33 


0.34 


0.34 




A 


dd to 


Obser 


ved P 


er Cei 


it. 






21 
22 
23 
24 
25 


0.04 
0. 10 
"0.16 
0. 21 
0.27 


0.05 
0. 10 
0. 16 
0.22 
0.28 


0.06 
0. II 
0.17 
0.23 
0.30 


0.06 
0.12 
0.17 
0.24 
0.31 


0.06 
0. 12 
0. 19 
0.26 
0.32 


0.07 
0.13 
0. 20 
0.27 
0.34 


0.07 
0.14 
0.21 
0.28 
0.35 


0.07 
0.14 
0.21 
0.29 
0.36 


0.07 
O.IS 
0. 22 
0.30 
0.38 


0.08 
O.IS 
0.23 
0.31 
0.38 


0.08 
0.16 
0. 24 
5.32 
0.39 


0.08 
0. 16 
0. 24 
0.32 
0.39 


0.08 
0.16 
0.24 
0.32 
0.40 


.0.09 
0.16 
0.24 
0.32 
0.39 


26 
27 
28 
29 

30 


0.33 
0.40 
0.46 
O.S4 
0.61 


0.34 
0.41 
0.47 
0.5s 
0.62 


0.36 
0.41 
0.49 
0.56 
0.63 


0.37 
0.44 
0.51 
0.59 
0.66 


0.40 
0.46 
O.S4 
0.61 
0.68 


0.40 
0.48 
0.56 
0.63 
0.71 


0.42 
o.so 
0.58 
0.66 
0.73 


0.44 

O.S2 
0.60 
0.68 
0.76 


0.46 
0.54 
0.61 
0.70 
0.78 


0.47 
0.54 
0.62 
0.70 
0.78 


0.47 
0.55 
0.63 
0.71 
0.79 


0.48 
0.56 
0.64 
0.72 
0.80 


0.48 
0.56 
0.64 
0.72 
0.80 


0.48 
0.56 
0.64 
0.72 
0.81 


35 


0.99 


1. 01 


1.02 


1.06 


1. 10 


1. 13 


1. 16 


I. 18 


1.20 


1. 21 


1.22 


1.22 


1.23 


1.22 


40 


1.42 


1. 45 


1.47 


I. 51 


1.54 


1.57 


1.60 


1.62 


1.64 


1.65 


1.65 


1.65 


1.66 


1.65 


45 


1. 91 


1.94 


1.96 


2.00 


2.03 


2.05 


2.07 


2.09 


2.10 


2. 10 


2. 10 


2.10 


2.10 


2.08 


50 


2.46 


2.48 


2.50 


2.53 


2.56 


2.57 


2.58 


2.59 


2.59 


2.58 


2.58 


2.57 


2.56 


2.52 


55 


3 -OS 


3.07 


3.09 


3.12 


3.12 


3.12 


3.12 


3. II 


3.10 


3.08 


3.07 


3.05 


3.03 


2.97 


60 


3 69 


3-72 


3-73 


3.73 


3.72 


3.70 


3.67 


3.65 


3.62 


3.60 


3.57 


3.54 


3.50 


3.43 


6S 

70 
75 
80 


4.4 
S-i 
6.1 

7-1 


4.4 
5.1 
6.0 
7.0 


4.4 
5.1 
6.0 

7.0 


4.4 
5.0 
5.9 
6.9 


4.4 
5.0 
5.8 
6.8 


4.4 
5.0 
5.8 
6.7 


4.3 
4.9 
5.7 
6.6 


4.2 
4.8 
5.6 
6.4 


4.2 
4.8 
5-5 
6.3 


4.1 
4.7 
5-4 
6.2 


4.1 
4.7 
5.4 
6.1 


4.0 
4.6 
5-3 
6.0 


4.0 
4.6 
5.2 
5.9 


3.9 

4.4 
5.0 
5.6 



* U. S. Dept. of Commerce and Labor, Bur. of Standards, Circular 44, 1913, p. 129. This table is 
calculated using the data on thermal expansion of sugar solutions by Plato (Wiss. Abh. der Kaiser- 
lichen Normal-Eichungs-Kommission, 2, 1900, p. 140), assuming the instrument to be of Jena i6''^ 
glass. The table should be used with caution and only for approximate results when the tempera- 
ture differs much from the standard temperature or from the temperature of the surrounding air. 



650 FOOD INSPECTION AND ANALYSIS. 

plying the reading by 2, both direct and invert. Use the Clerget-Herzfeld 
formula for calculation of the sucrose. 

For medium- or light-colored grades of molasses, which yield but 
a small precipitate with lead subacetate, the above method of simple 
polarization, both direct and invert, gives results sufficiently accurate 
for ordinary work. For dark-colored, or "black-strap" molasses, or 
wherever extreme accuracy is required, the solution should be first 
made up to the mark and then clarified by the addition of a 
slight excess of anhydrous lead subacetate (p. 610), as proposed by 
Home, or else the double dilution method of Wiley should be em- 
ployed. Both methods make due allowance for the volume of the pre- 
cipitate. 

Double Dilution Method.^ — Take half the normal weight of the sample 
md make up the solution to 100 cc, using the appropriate clarifier. Take 
the normal weight of the sample and make up a second solution with the 
clarifier to 100 cc. Filter and obtain direct polariscopic readings of 
both solutions. Invert each in the usual manner and obtain the invert 
reading of the two. 

The true direct polarization of the sample is the product of the two 
direct readings divided by their difference. The true invert polariza- 
tion is the product of the two invert readings divided by their dif- 
ference. 

Determination of Raffinose in Beet Sugar Molasses. — For the deter- 
mination of sucrose and raffinose when present in the same solution, use 
the following formulas of Creydt as modified by Browne t to correspond 
with the Clerget-Herzfeld method of inversion: 

0.5124^-6 

•^ 0.839 ' 
and 

a-5 

or 

0.3266a -l-& 



R= 



1-554 



where 5= per cent of sucrose, 7? = per cent of raffinose, a = direct reading, 
and 6 = reading after inversion. 

* Wiley and Ehvell, Analyst, i8q6, 21, p. 184. 

t Handbook of Sugar Analysis, New York, 191 2, p. 283. 



SUGAR AND SACCHARINE PRODUCTS. 651 

Davoll * recommends for purposes of clarification of tlie molasses the 
ase of powdered zinc after inversion of the molasses sample according to 
Clerget's method. He adds i gram of the zinc to the sample after in- 
version while at the temperature of 69° C, allowing it to act for three to 
fov.r minutes at that temperature, after which he cools and filters, with 
the production of an almost colorless solution. 

Determination of Reducing Sugar. — {Estimated as Dextrose.) — Dilute 
5 grams of molasses or syrup with water in a loo-cc. graduated flask, 
using 2 to 5 cc. normal lead acetate. Make up to 100 cc, filter, take 
an aliquot part of the filtrate (25 to 50 cc.) and make this up to 100 
cc, the amount taken being such that, when diluted, the solution will 
contain not more than J% of dextrose. Since lead acetate has been 
used to clarify, add to the aliquot part taken and before dilution, enough 
sodium sulphate to precipitate the excess of lead, then filter and make 
up to the 100 cc. mark. 

Determine the reducing sugar in this solution by either volumetric 
or gravimetric Fehling processes. 

U. S. Standard Molasses is molasses containing not more than 25% 
of water, nor more than 5% of ash. 

Adulteration of Molasses and Syrups. — A common adulterant of all 
these products is commercial glucose. From its water-white color and 
inert sweetness, no less than from its cheapness, it forms an admirable 
adulterant for dark-colored or low-grade molasses and syrups, counter- 
acting to a great extent by its smoothness the strong and often disagree- 
able taste of the inferior products with which it is mixed. Thus a grade 
of molasses too cheap to be ordinarily used for food purposes can be 
made to assume the appearance, and to some extent the taste, of the 
higher-priced and light-colored grades, by admixture with commercial, 
glucose. 

Tin salts are also used to improve the color of low-grade or dark 
molasses, and bleaching agents, such as sulphurous acid, are frequently 
employed. Copper is sometimes found, due to utensils or vessels used 
in processes of manufacture. 

Lead may occur in maple syrup, due to the leaden plugs or spigots 
through which the sap is sometimes drawn from the trees. 

Detection and Determination of Commercial Glucose.f — From the 
direct polarization of a normal solution of molasses or syrup the presence 

* Jour. Am. Chem. Soc, 25 (1903), p. 1019. 
t Leach, ibid., p. 982. 



652 FOOD INSPECTION AND ANALYSI§. 

or absence of commercial glucose can usually be established. The direct 
polarization of a normal solution of pure molasses should not be much in 
excess of 50° on the Soleil-Ventzke scale, while a pure, dark-colored molas- 
ses should polarize well under 40°. Golden syrup and maple syrup 
read higher than molasses, and a normal solution of pure maple syrup 
may have a direct polarization as high as 65°, being more often than not 
above 60°. 

An excessively high direct polarization is at once an indication of 
the presence of commercial glucose, while an invert reading at ordinary 
room temperature to the right of the zero-point is an almost positive 
proof of its presence in either of the above products. 

The optically active constituents of commercial glucose, viz., dextrin, 
maltose, and dextrose, are present in such varying amounts, that it is 
impossible to determine accurately the exact amount of this adulterant 
in complex saccharine products which themselves contain components 
common to glucose. Its approximate amount can, however, be very 
satisfactorily estimated in molasses and syrups by the use of the follow- 
ing formula: 

175 ' 

where G = per cent of commercial glucose, a = direct polarization, and 
5= per cent of cane sugar previously obtained from the Clerget-Herzfeld 
formula. A large amount of invert sugar present affects the accuracy of 
this formula. It is especially applicable to maple syrup, wherein the 
per cent of invert sugar is small, but may be applied also to molasses and 
golden syrup, wherein the amount of invert sugar is not so large but that 
results may be obtained as close as it could be expected from an empirical 
formula.! 

In saccharine products containing considerable invert sugar the 
invert reading at 87° C. obtained as directed on page 671, is divided by 

* Leach, U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 48. 

t This formula is based on the assumption that 42° Be. mixing glucose, the grade 
specially made and used for admixture with molasses, syrups, and honey, has a maximum 
polarization of 175° V. It was adopted as a result of investigations made some years ago 
by the author, but subsequently it appeared that 42° Be. mixing glucose polarizes lower 
than formerly. Thus a sample recently examined by the author polarized at 162.4° V. 
Pending further investigations it seems best for the present to retain the old formula, for, 
while it undoubtedly gives low results, especially with higher admixtures of glucose, it 
approximates the truth more closely than would be expected, perhaps because it tends to 
compensate for the error due to substances in genuine molasses and honey that polarize 
to the right after inversion. Furthermore, it has been adopted by the A. O. A. C. To 
avoid misunderstanding, express results in terms of glucose polarizing at that factor. 



SUGAR AND SACCHARINE PRODUCTS. 



653 



the appropriate factor (163) to obtain the percentage of commercial 
glucose. 

While theoretically pure molasses and syrups would be expected to 
show no rotation when polarized at 87° C. after inversion, as a matter 
of fact most samples exhibit a decidedly right-handed reading at that 
temperature. Occasionally a zero reading is noted, and in rare instances 
a slight left-handed rotation occurs under the above conditions, 

Dextro-rotation is undoubtedly caused by some form of decomposition 
or fermentation. It may be due to a preponderance of dextrose in the 
reducing sugars, since levulose is more easily decomposed than dextrose, 
or it may be caused by the decomposition products formed when the raw 
juice is being defecated with lime, or again it might result from a special 
fermentation forming dextran. 

The following table shows results by A. H. Bryan* of polarization of 
samples of Louisiana molasses and syrup of known purity, showing 
especially the invert readings at 87° C: 

POLARIZATION OF LOUISIANA MOLASSES AND SYRUP. 



MOLASSES. 


SYRUP. 


Direct 
Polariza- 
tion 
at 20° C. 


Corrected Invert 
Polarization — 


Dry 
Substance. 


Direct 
Polariza- 
tion 
at 20° C. 


Corrected Invert 
Polari zation — 


Dry 
Substance. 


At 20° C. 


At 87° C. 


At 20° C. 


At 87° C. 


° V. 
40.8 
24.6 
26.0 
42.4 
52-4 
55-6 
39-6 
39-6 


° V. 

— 20.24 

— 20.9 
-18.26 
-16.94 
-16.28 

-13-59 

— 18.04 
-17.82 

— 17.16 

— 17.60 
-17.27 
-16.94 

— 1 7 . 60 
-19.8 
-25.08 

— 16.72 
-14.74 
-15-4 


° V. 

+ 2.2 
+ 2.2 

+ 3-52 
+ 2.42 
+ 2.20 
+ 4.18 
+ 2. 20 
+ 2.20 
+ 2.64 
+ 2.42 
+ 3-52 
+ 3.96 

+ 3-52 
0.00 

+ I.IO 

+ 3-96 

+ I.IO 

+ 2.20 


Per Cent. 
80.8 
76.8 
76.8 
78.2 
69.1 
69.6 
80.8 
79.0 
72.0 
73-8 
76.1 
74.0 
76.1 
78.1 

87-5 
84.1 

75-0 
78.0 


° v. 

48.4 
54-0 
50.2 
50-4 
61.8 


° V. 
-17.6 
-18.7 
— 12. 1 

-14-3 
-16.5 


° V. 
+ 1.98 

+ 3-3° 
+ 6.i6t 
+ 1.76 
+ 2.20 


Per Cent. 

74-3 
68.3 


Average. 
Maximui 
Minimur 




+ 2.65 

+ 6.16 

0.00 




44.0 
42.0 


n 

n. 




42.4 
41.6 

52-4 
26.6 
50.8 
22.6 
41.6 
45-6 









* A. O. A. C. Proc, 1908, U. S. Dept. of 
■\ Sample ropy and badly fermented. 



jric, Bur. of Chem., Bui. 122, p. 182. 



1 



654 



FOOD INSPECTION AND ANALYSIS. 



TYPICAL ANALYSES OF MOLASSES AND SYRUPS ADULTERATED WITH 

COMMERCIAL GLUCOSE. 



Polarization. 



§ O Of? 
<-> o aj C 
u 3fi p 



bcQ 



"S ii-"i 



U 






(a) Molasses 

W " 

(c) " 

(a) Golden drip syrup 
(6) " " 

(c) " 

''a) Maple syrup 

(b) " " 

(0 " " 



62 

98 

109 

73 
109 

143 
76 

77 
87 



+ 36.3 
+ 71-9 
+ 90 

+ 39-8 
+ 87.6 
+ 136.0 
+ 7.6 
+ 24 
+ 30.6 



18° 

18° 

17° 

18° 

17° 

18.4° 

18.6° 

19° 
22.4° 



19 
19.9 

14-5 

25 

16.9 

5-6 

51 
40.1 

42.5 



30-03 
27.62 

33-11 
31.61 

33-44 
38-17 
10.55 



16. QO 



24.6 

45 -o 
54-4 
27.7 
52.8 

78.5 
14.4 
21.6 

25.4 



29.36 
27.98 
22.02 
23.67 
24.48 
21.52 
31-91 
23-44 
28.80 



3-83 
3-53 
2.67 

3-94 
2-51 
1. 00 
0.65 

1.08 



Determination of Dextrin. — According to Beckman's method a 
weighed amount of the honey or molasses is diluted with an equal volume 
of water and from ten to twelve times its volume of methyl alcohol is 
added. The precipitated dextrin is collected in a tared filter and thor- 
oughly washed with methyl alcohol, after which it is dried and weighed. 

Reduction of Saccharine Products to an Ash for Mineral Analysis. 
— If a considerable quantity of molasses, syrup, or other saccharine sub- 
stance is to be burnt to an ash, it is both tedious and annoying to ignite 
directly, by reason of the excessive swelling and frothing of such substances 
during ignition. Small quantities of molasses, syrup, or honey may with 
care be reduced to an ash by the method described on page 609. 

If a readily controlled electric current is available, it may be utilized 
as follows : * Mix 100 grams cf molasses, syrup, or other saccharine 
solution, which should be evaporated to syrupy consistency if not already 
such, with about 35 grams of concentrated sulphuric acid in a large 
porcelain evaporating-dish. An electric current is then passed through 
it while stirring, by placing one platinum electrode in the bottom of the 
dish near one side and attaching the other to the lower end of the glass 
rod, with which the contents are stirred. Begin with a current of about 
I ampere and gradually increase to 4.f In from ten to fifteen minutes 

* Leach, 32d An. Rept. Mass. State Board of Health (1900), p. 653. Reprint, p. 37. 
This method is preferred to the ordinary method of heating with sulphuric acid, especially 
in case of molasses, because, if properly manipulated, it so quietly comes into the form of a 
very finely divided char or powder, especially adapted for subsequent quick ignition. 

f Modified from method of Budde and Schou for determining nitrogen electrolyticall/. 
Ztschr. anal. Chem., 38 (1899), p. 345. 



SUGAR AND SACCHARINE PRODUCTS. 655 

the mass is reduced to a fine, dry char, which may then be readily burnt 
to a white ash in the original dish over a free flame or in a muffle. 

Or, ICO grams of the molasses or syrupy solution to be ashed may 
be first evaporated to dryness and afterward mixed with from lo to 20 cc. 
of concentrated sulphuric acid in a porcelain evaporating-dish, or if the 
substance to be ashed be a dr}^ sugar or confectioneiy, 20 grams are 
mixed with the above amount of acid. Heat is gently applied by means 
of the gas flame till the swelling and frothing have ceased, which usually 
requires only a few minutes. The final ignition is then accomplished 
in the usual manner, nitric acid being added if necessary to completely 
destroy the organic matter. 

Determination of Tin in Molasses. — Fuse the ash from a weighed 
portion of the sample with sodium hydroxide in a silver crucible, dis- 
soh'e in water, and acidulate with hydrochloric acid; filter and precipi- 
tate the tin from this solution with hydrogen sulphide; wash the pre- 
cipitate on a filter and dissolve it in an excess of ammonium sulphide. 
Filter this solution into a tared platinum dish, and deposit the tin directly 
in the dish by electrolysis, using a current of 0.05 ampere and the appa- 
ratus described on page 634. 

Distinction between Invert Sugar, Maltose, and Lactose.* — All these 
sugars reduce Fehling's solution. Dextrose and Icvulose (invert sugar) 
when boiled with Barfoed's copper acetate solution (14 grams crystal- 
lized copper acetate and 5 cc. acetic acid in 200 cc. water) will form 
a precipitate of cuprous oxide, while neither maltose nor lactose will 
do this. The solution, which has thus been tested for invert sugar and 
found to be free, or the filtrate from the cuprous oxide precipitate, is 
treated with an excess of basic lead acetate, filtered, and to the filtrate 
is added an excess of sodium sulphate solution to precipitate the lead. 
The solution 13 again filtered and treated with copper sulphate solution, 
if not already blue. It is then made alkaline with sodium hydroxide 
and heated to boiling. A red precipitate of cuprous oxide at this stage 
indicates either lactose or maltose or both. 

A solution of the sugar, made strongly ammoniacal, is then mixed 
with alkaline bismuth solution f and the container is set in a water- 
bath at 60° C. Maltose soon reduces the bismuth, but lactose does not. 

To test for lactose, add strong nitric acid to the solid sugar residue 

* Bartley and Mayer, Merck's Report, 12 (1903), p. 100. 

t This reagent is prepared as follows: Bismuth subnitrate, 2 grams; Rochelle salt, i 
grams; sodium hydroxide, 8 grams; dissolved in 100 cc. of water by the aid of heat. 



656 FOOD INSPECTION AND ANALYSIS. 

and warm gently till red fumes come off. Then set the container in hot 
water and cool gradually. Crystals of mucic acid appear after a time 
if any appreciable amount of lactose be present. 

Determitiation of Lactose or Maltose. — Either sugar, if in solution 
free from other reducing sugars, may be determined by the volumetric 
Fehling method (page 615) or by the Defren method, using the table 
on page 619. 

For the determination of maltose in commercial glucose, see page 661. 

Estimation of Cane Sugar and Dextrose in Mixtures. — Obtain true 
direct and invert readings of a normal solution of the mixture. Deter- 
mine the per cent of sucrose by Clerget-Herzfeld formula. This figure 
represents the right-handed rotation due to a sucrose. Subtracting this 
from the direct polarization, the difference represents the right-handed 
rotation due to dextrose. The specific rotatory power of sucrose is 66.5 
and that of dextrose 52.76. 

Calling d the percentage of dextrose and R' the right-handed rota- 
tion due to dextrose as above obtained, if the Soleil-Ventzke scale is used. 

66.5:52.76 = c?:i?', 
whence 

66.57?' 



d= 



52.76* 



ANALYSIS OF MAPLE PRODUCTS. 

Preparation of Sample. — S3rrups are analyzed in the condition they are 
placed on the market, rejecting any sediment which may have settled out. 
Jones has noted that if maple sugar is analyzed in its commercial form the 
results would include mineral matter and other insoluble constituents 
which might invite a considerable admixture of ordinary sugar. It is 
therefore important to carry out the analysis on a syrup prepared according 
to Bryan * as follows : 

Dissolve 100 grams of the sugar in at least 200 cc. of water and boil down 
to 65% of solids. If the solution is cloudy, filter after the liquid has been 
boiled down to about ^0% of solids, then complete the concentration. 
Allow to stand at 20° C. for two days and decant from the sediment. 

Determination of Moisture. — This is accomplished by direct drying 
with sand, or by calculation from the specific gravity, or, preferably from 
the refractive index. See molasses methods, page 643. 

* A. W. Bryan, U. S. Dept. of Agric, Bur. of Chem., Circ. 40, p. 6. 



SUGAR AND SACCHARINE PRODUCTS. 657 

Determination of Ash. — Burn 5 grams in a platinum dish by the usual 
method, observing the precautions given for molasses, page 644. 

Soluble and Insoluble Ash* — To the platinum dish containing the 
ash add 40 cc. of hot water and boil gently for two minutes. Filter through 
a small ashless filter, and wash with hot water until the filtrate amounts 
to ICO cc. Return the filter to the dish used for ashing, burn at a low 
red heat, cool and weigh, thus obtaining the insoluble ash. The soluble 
ash is obtained by difference, subtracting the weight of insoluble from 
that of total ash. 

Alkalinity of Soluble Ash."^ — Allow the filtrate from the above deter- 
mination to cool, then titrate with tenth-normal hydrochloric acid, using 
methyl orange as an indicator. 

Alkalinity of Insoluble Ash.* — Add excess of tenth-normal hydrochloric 
acid (usually 10 cc.) to the ignited insoluble ash in the platinum dish, 
boil gently, cool and titrate with tenth-normal sodium hydroxide, using 
methyl orange as an indicator. 

Express the alkalinity in each case as the number of cubic centimeters 
of tenth-normal acid on the ash of i gram of sample. 

Determination of Sucrose. — Calculate by Clerget-Herzfeld formula 
(page 610). Use 5 cc. of alumina cream but no lead subacetate except 
when necessary and then but i cc. 

Determination of Reducing Sugar. — Follow Defren-O' Sullivan or 
Munson and Walker method (pages 618 and 622). 

Determination of Malic Acid Value. — Leach and Lythgoe Method, f 
modified by Cowles.X — The modified method differs from the original 
chiefly in that no ammonia is added and calcium acetate is substituted 
for calcium chloride ; it gives slightly higher results. 

Weigh 6.7 grams of the sample in a sugar dish, transfer to a 200-cc. 
beaker with 5 cc. of water, add 2 cc. of a 10% calcium acetate solution, 
and shake. Stir in 100 cc. of 95 per cent alcohol and warm the solution 
until the precipitate settles, leaving the supernatant liquid clear. Filter 
off the precipitate and wash with 75 cc, of 85% alcohol, dry the filter paper, 
and ignite in a platinum dish. Add 10 cc. of tenth-normal hydrochloric 
acid and warm gently until all the lime dissolves. Cool and titrate back 
with tenth-normal sodium hydroxide, using methyl orange as an indicator. 
One-tenth of the number of cubic centimeters of tenth-normal acid is the 

* A. H. Bryan, U. S. Dept. ofAgric, Bur. of Chem., Circ. 40, p. 6. 

t Jour. Amer. Chem. Soc, 26, 1904, pp. 380, 1536. 

t Ibid., 30, 1908, p. 1285; U. S. Dept. of Agr., Bui. 466, 1917, p. 11, 



658 FOOD INSPECTION AND ANALYSIS. 

malic acid value. Run a blank determination with each set of deter- 
minations, using the same amount of reagents, and subtract the result 
obtained from the malic acid number. 

Determination of Lead Number. — Winton Method* — Weigh 25 
gi-ams of the material (or 26 grams if a portion of the filtrate is to be used 
for polarization) and transfer by means of boiled water into a loo-cc. 
flask. Add 25 cc. of standard lead subacetate solution, fill to the mark, 
shake, allow to stand at least three hours and filter through a dry filter. 
From the clear filtrate, pipette off 10 cc, dilute to 50 cc, add a moderate 
excess of sulphuric acid, and 100 cc. of 95% alcohol. Let stand over 
night, filter on a Gooch crucible, wash with 95% alcohol, dry at a moderate 
heat, ignite at low redness for three minutes, taking care to avoid the re- 
ducing cone of the flame, cool, and weigh. Calculate the amount of lead 
in the precipitate, using the factor 0.6831, subtract this from the amount 
of lead in 2.5 cc. of the standard solution, multiply the remainder by 
100, and divide by 2.5, thus obtaining the lead number. 

The standard lead subacetate is prepared by diluting one part of 
the ordinary solution (page 610) with four volumes of water, filtering 
if not clear. It is standardized by a blank determination conducted as 
above described, but acidifying with a few drops of acetic acid before 
making up to volume, as recommended by A. H. Bryan. The solution 
deposits a slight precipitate on standing, but this does not usually appre- 
ciably affect its strength. 

The range in lead number of maple products calculated to the dry 
basis is given on pages 593 and 594; Snell and Scott have shown, how- 
e\'er, that the range in the case of syrups is narrower when the compari- 
son is made on the wet basis. 

Adding of cane sugar reduces the lead number to a greater degree 
than the percentage of admixture thus rendering the fact more apparent, 

Ross Modification. '\ — This process yields higher results than the original 
methods (see page 594). The number of mixtures of maple and cane 
syrups (or sugars) is proportional to the admixture. 

Transfer 25 grams of the syrup to a loo-cc flask, using about 25 cc. 
of freshly boiled water, add 10 cc. of potassium sulphate solution (7 grams 
per liter), then 25 cc. of lead subacetate solution of the strength employed 
in the foregoing method. Make up to the mark with boiled water and 
proceed as in the Winton method. 

* Jour. Am. Chem. Soc, 28, 1Q06, p. 1204. 

t U. S. Dept. of Agric, Bur. of Chem., Circ. 53, 



SUGAR AND SACCHARINE PRODUCTS. 659 

Run the blank in exactly the same way, substituting 25 grams of pure 
cane sugar syrup (66 grams of sucrose dissolved in 34 grams of water) 
for the maple syrup. 

McGill or Canadian Method."^ — To 5 grams of the dry sugar, or its 
equivalent in syrup, dissolved in water and made up to 20 cc, add 2 cc. 
of lead subacetate solution, mix and allow to stand for two hours. Filter 
on a Gooch crucible, or sugar tube packed with asbestos, wash 4 to 5 
times with hot water, dry, and weigh. Multiply the weight by 20 to obtain 
the lead number. 

In genuine maple syrups McGill found a range of 1.37 to 6.56 for 
456 samples (using 5 grams of syrup), Snell and Scott a range of 1.74 to 
7.50 for 126 samples (using 5 grams of dry matter). 

Snell, MacFarlane, and Von Zoeren Volumetric Method.'\ — Dilute the 
syrups with water, boil until the temperature reaches 219° F, and filter 
through cotton wool. After cooling, dilute to cc. to 100 cc. with distilled 
water, and measure 60 cc. of the diluted solution into a loo-cc. beaker. 

Measure the electrical resistance using a dip electrode as described 
for the Snell method of determining electrical resistance (page 661). 
Maintaining the temperature constant, add i cc. of lead acetate solution 
(a filtered solution of Home's lead subacetate sp.gr. 1.033) ^^m a burette, 
stir well, and again measure the electrical resistance. Continue the addi- 
tion in this manner, i cc. at a time, until 10 cc. have been added. Plot 
the resistances found against the quantities of subacetate solution used. 
If the syrup is genuine the results of the plot will be two intersecting straight 
lines. In 70 genuine maple syrups examined by the originators of the 
method the intersections fell between 4.8 and 6.6 cc. 

Pure maple sugars converted into syrups give practically the same values 
as pure syrups. | 

Determination of Volume of Lead Precipitate. § — Hortvet Method. — 
The apparatus consists of (i) a tube, 15.3 cm. in length, made up of a 
wide cylindrical portion 3 cm, in diameter, narrowed at the top to a neck 
2 cm. in diameter, and at the bottom to a stem graduated in tenths to 5 cc. 
and (2) a holder, made of pine or white wood, of a size adapted to carry 
the tube in the shield of the centrifuge. The holders and tubes should 
be arranged in balanced pairs in the centrifuge. 

* Lab. Ind. Rev. Dept., Ottowa, Bui. 228, 1911, p. $. 

t Jour. Ind. Eng. Chem., 8, 1916, p. 241. 

X Ibid., 8, 1916, p. 421. 

§ Jour. Am. Chem. Soc, 26, 1904, p. 1532. 



1 



660 FOOD INSPECTION AND ANALYSIS, f 

Introduce 5 cc. of syrup or 5 grams of sugar into the tube. Add 10 cc. 
of water, and dissolve completely. Next add 10 drops of alumina cream, 
and 1.5 of lead subacetate. Shake thoroughly, and allow to stand from 
forty-five to sixty minutes. Place the tube in its holder in the centrifuge 
shield, and run six minutes. If, after the end of this time, any material 
adheres to the sides of the wide part of the tube, loosen with a small wire 
or by giving the tube a slight twist, then run the tube six additional minutes, 
and finally read the volume of the precipitate in the stem, estimating to 
o.oi cc. 

Run a blank with the above reagents in water, subtracting the blank 
reading from that of the precipitate. In the case of syrup, reduce to 
the 5-gram basis by dividing by the specific gravity of the sample. If 
the sugar content of the sample is known, the specific gravity can be 
calculated from the table on page 648. For pure maple syrup 1.33 is 
very nearly correct. 

The centrifuge used by Hortvet had a radius of 18.5 cm. and was run 
at a speed of 1600 revolutions per minute. The corresponding velocity 
in cm. per second (v) and revolutions per minute (R) for any given centri- 
fuge with a radius of r cm. may be calculated by the following formula): 

v=\/^2o,ooor, R = 6ov/2irr. 

Results by Hortvet on pure maple syrups vary from 1.2 cc. to about 
2.5 cc, and on pure maple sugars from 1.8 to 4 cc. 

Commercial brands of adulterated syrups and sugars give such pre- 
cipitates as 0.00 cc, 0.02 cc, 0.05 cc, and 0.08 cc Hortvet regards with 
suspicion a syrup testing lower than 1.2 cc, and when the result is below 
I cc, the sample is positively condemned as being mixed with refined 
cane sugar. In the case of sugar, a somewhat higher minimum figure 
is adopted than with syrup. In view of the fact that the speed has much 
to do with the volume of the precipitate, the analyst should make a series 
of similar experiments with his own centrifuge, and work out his own 
standards. Results may be better compared with each other, if calculated 
on the water-free basis. 

In case of doubt, and in fact in all cases at first, it would be well to 
make confirmatory tests, such as determining the ash and reducing sugar. 

Sy's Lead Method.* — In a 25-cc. graduated cylinder introduce 5 cc. 
of syrup, or 5 grams of sugar which is afterwards dissolved in a little 

* Jour. Am. Chem. Soc, 30, 1908, p. 1430. 



SUGAR AND SACCHARINE PRODUCTS. 661 

water. Add water to the 15 cc. mark and 2 cc. of lead subacetate solution. 
Shake thoroughly and allow the mixture to stand twenty hours. Then 
read the volume of the precipitate, which for pure maple products should 
be at least 3 cc. and is usually over 5 cc. 

Determination of Electrical Conductivity Value. — Snell Method.'^ — 
Measure out into a small beaker (or directly into the conductivity cell) 
20 cc. of the syrup, allowing thorough draining. Using the same graduate, 
add two successive portions of water, each equal in volume to the syrup 
taken. Mix thoroughly, pour into conductivity cell, bring to 25° C, 
and make the measurement. Divide the constant of the cell by the observed 
number of ohms and multiply the result by 100,000. 

Genuine syrups examined by Snell and co-worker have given values 
of 96 to 230. 

The essential features of the apparatus are: 

1. A low voltage electrical current operating an induction coil. 

2. A conductivity cell of a form suitable for liquids of low conductivity, 
and with electrodes not easily displaced.! 

3. A Wheatstone bridge with telephone. 

4. A device for exact regulation of temperature. 

ANALYSIS OF COMMERCIAL GLUCOSE. 

Wiley X has worked out a method for calculating the percentage of 
dextrin, maltose, and dextrose present in commercial glucose, based 
on the specific rotatory power of these substances and on the reducing 
power of maltose and dextrose. To apply this method, the operator, 
if he has a polariscope reading in sugar scale degrees, must ascertain 
the equivalent readings in angular degrees from the table on page 606, 
and calculate the specific rotatory power in each case from the formula 

(«)o=-^, page 607. 

Thus, if he possesses a Schmidt and Haensch instrument, he should 
multiply the true reading, as obtained on that instrument, with a normal 
solution of the given sugar or mixture, by the factor 0.3468, to convert 
the reading into circular degrees from which to figure the specific 
rotatory power as above. 

* Jour. Ind. Eng. Chem., 5, 19 13, p. 740. 

t Van Zoeren, Jour. Amer. Chem. Soc, 38, 1916, p. 652. 

% Chem. News, 46, p. 175; Agric. Anal., 3, pp. 288-290. 



662 FOOD INSPECTION AND ANALYSIS. 

The specific rotatory power of dextrin is fixed at 193, that of maltose 
at 138, and that of dextrose at 53. 

Then if P = total polarization of the mixture in terms of specific 
rotatory power, c?==per cent dextrose, m = per cent maltose, and c?' = per 
cent dextrin, 

P-53(/ + i38w + i93(i'. . (i) 

The value of P is obtained from observation and calculation as above 
described on a known solution of the sample, say 10 grams in ico cc. 
The reducing sugars, maltose and dextrose, are then removed, prefer- 
ably by oxidation with cyanide of mercury, as follows :* 

Prepare the reagent by dissolving 120 grams mercuric cyanide and 
120 grams sodium hydroxide in water, mixing the two solutions, and 
making up to 1000 cc. Remove any precipitate that may gather by 
filtration. 

Make a solution of 10 grams of the glucose sample in 100 cc. and 
take 10 cc. of this solution in a 50-cc. graduated flask. Add sufiicient 
mercuric cyanide solution to have an excess of reagent after the oxidation 
(from 20 to 25 cc), and boil for three minutes under a hood with a good 
draft. Cool and neutralize the alkali with concentrated hydrochloric 
acid, adding the latter till the brown color is discharged. By this method 
the optical activity of the maltose and dextrose is discharged, while that 
of the dextrin remains unaffected. From the polariscope reading cal- 
culate as above the specific rotatory power of the dextrin (P'), Then 

P'=^92>d' (2) 

The reducing power on Fehling's solution of dextrose is to that cf 

maltose as 100 is to 62. Whence, if i? = reducing sugar (reckoned as 

dextrose) we have 

R = d+o.62m (3) 

Subtracting equation (2) from equation (i) we have 

P-P' = 53^ + i38m (4) 

Multiplying equation (3) by 53 and subtracting from equation (4), 

P-P' = 53^ + i38m, 

53^ = 53^+32-86w, 

P-P^ -53^= 105-14^ (5) 

* Wiley, Agric. Anal., p. 290. 



1 



SUGAR AND SACCHARINE PRODUCTS. 663 

Therefore 

w= T^^TT, — ' (^) 

105.14 /^ 

d = R— 0.62m, (7) 

d' =— (8) 

193 

Determination of Dextrin in Commercial Glucose. — One volume of 
the sample is well shaken with about 10 volumes of 90% alcohol, and 
the precipitated dextrin is separated by filtration through a tared filter, 
washed thoroughly with strong alcohol, dried at 100°, and weighed. 

Qualitative Tests for Commercial Glucose. — Several confirmatory 
chemical tests may be employed for commercial glucose, aside from 
the optical test with the polariscope. Thus a precipitate of dextrin by 
treatment of the sample with an excess of strong alcohol, in the absence 
of mineral salts insoluble in alcohol, is strongly indicative of commercial 
glucose. An excess of sodium chloride in the ash also points strongly to 
the presence of glucose. 

Determination of Ash. — Formerly, when sulphuric acid was used for 
conversion of the starch, the ash consisted largely of calcium sulphate, but 
at present when hydrochloric acid is almost exclusively used the mineral 
matter is almost entirely common salt, formed by the neutralization of the 
acid. 

Determine ash by burning in a platinum dish at dull redness as in the 
case of other saccharine products. Qualitative or quantitative tests 
may be made for chloride, in the latter case calculating the equivalent 
amount of sodium chloride. If the amount of sodium chloride found 
does not equal the total ash, sulphates may be looked for. 

Determination of Sulphurous Acid. — At the present time glucose 
usually is free from an appreciable amount of sulphurous acid which 
formerly was extensively employed for bleaching. It may be determined 
by distillation, oxidation to sulphuric acid, and precipitation with barium 
chloride as described on page 313. 

Detection of Arsenic. — Since the Manchester epidemic of arsenical 
poisoning, due to the consumption of beer prepared from glucose con- 
taminated through the sulphuric acid with this poison, it is highly important 
that both the acid used for conversion and the glucose be frequently 
tested for this contamination. 



664 FOOD INSPECTION AND ANALYSIS. 

The tests may be made on 2 to 5 grams of the materials without charring 
or destruction of the organic matter, by the Marsh test or the Sanger- 
Black-Gutzeit test as described under general methods on pages 63 to 66. 

The English limit of one and one-half parts per million calculated 
as metallic arsenic should not be exceeded. 

HONEY. 

Composition and Occurrence. — Honey is the saccharine product 
deposited by bees {Apis mellijica and A. dorsata) in the cells of honey- 
comb, which the insect forms out of wax secreted by its body. Honey 
has its source chiefly in the nectares of flowers, from which the bees 
abstract it, also in the juices of ripe fruits and the exudations of leaves 
(honeydew). While in the honey-sac of the bee, the sucrose, which 
forms the chief constituent of the fruit juice or nectar, becomes for the 
most part inverted, forming, in the honey, dextrose and levulose. The 
evaporation to a syrupy consistency is effected in the hive by exposure 
to a current of air, produced by fanning of the wings of the bees. 

The flavor of honey varies considerably, according to its source. 
Besides water and the sugars named honey contains dextrin and small 
amounts of protein, mineral matter (including phosphates), and organic 
acids. Pollen is usually present, also as a rule a small quantity of wax. 
Fincke * states real honey may or may not contain formic acid. 

European Honey. — Neufeld f gives the following limits for pure 
honey : 

Water 8.30 to 33.59% 

Protein 0.03 to 2.67% 

Invert sugar 49 . 59 to 93 . 96% 

Sucrose o . 10 to 10 . 12% 

Dextrin 0.99 to 9.70% 

Formic acid 0.03 to 0.21% 

Ash 0.02 to 0.68% 

Canadian Honey.— A large number of samples of genuine honey 
analyzed in 1897 for the Department of Inland Revenue, Canada (Bui, 
47), showed the following variations: 



* Zeits. Unters. Nahr. Genussm., 23, 1912, p. 255. 

t Der Nahrungsmittelchemiker als Sachverstandiger, Berlin, 1907, p. 275. 



SUGAR AND SACCHARINE PRODUCTS. 665 

Direct polarization — 2.4 to — 19 

Invert " -10.2 " -28 

Sucrose (by Clerget) 0.5 " 7. 64% 

Invert sugar 60.37 " 78.8% 

Water 12 '* t,t,% 

Ash 0.03 " 0.50% 

American Honey. — Browne* has examined 97 samples of American 
and Hawaiian honey, representing the product made from the nectar 
of numerous flowers as well as honeydew. Maxima and minima of 
polarizations and analyses of some of the more important kinds, and of 
all the levorotatory and the dextrorotatory samples are given in the table 
on page 666. 

As regards the chemical characteristics of honey from different flowers, 
Browne states that alfalfa honey usually has less dextrin and undetermined 
matter — the so-called ' impurities " — and more sucrose than the other 
varieties, although the low amount of impurities is, to some extent, char- 
acteristic of the honey of the whole family (leguminosa?) . The compositae 
yield honey with about the average amount of organic non-sugars; the 
rosaceae yield a product low in dextrin, but high in undetermined m tter. 
Buckwheat and other polygonaceous honeys contain almost no sucrose, 
but give tests for tannins. Basswood honey is relatively high in dextrin, 
and that from poplar, oak, hickory and other trees, all of which contain 
considerable quantities of honeydew, are rich in both dextrin and ash. 
Pronounced tannin reactions are obtained in honey gathered from the 
flowers or plants of the sumac, hop and others rich in tannin. Tupelo, 
mangrove and sage honeys are distinguished by their high levulose content. 

Browne found the average per cent of water in honey from the arid 
states of Arizona, Nevada, Utah, and Colorado was 15.60, and from the 
humid states of Minnesota, Wisconsin, Illinois, Missouri and Iowa was 
18.88. 

Hawaiian Honey. — This is characterized by its high ash and the 
presence of decided amounts of chlorides in the ash. Van Dinef states 
that the floral honey of Hawaii is largely from the blossoms of the algarroba 
{Prosopis juliferd), while the honeydew honey, which, together with 
mixtures of honeydew and floral honey forms about two-thirds of the 



* U. S. Dept. of Agric, Bur. of Chem., Bui. no (1908 
flbid., p. 52. 



666 



FOOD INSPECTION AND ANALYSIS. 






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SUGAR AND SACCHARINE PRODUCTS. 



667 



product of the Hawaiian Islands, comes largely from the exudations of 
the sugar-cane leaf-hopper {Perkinsiella saccharicida) , and the sugar- 
cane aphis {Aphis sacchari). Honeydew honey is dextrorotatory, and 
for this reason has often been condemned as adulterated. It has a strong 
molasses-like odor, and often a very dark color. Bakers prefer it to 
algarroba honey, because of its baking and boiling properties. 

The variation in the composition of Hawaiian honey is shown in the 
table on page 666, compiled from Browne's data. 

Cuban, Mexican, and Haitian Honey. — The following table contains 
analyses of :i^T, Cuban, 23 Mexican, and 16 Haitian honeys by A. H. Bryan.* 
One of the samples gave a faint color with Browne's test, but not 
sufficient to confuse the sample with honey containing an appreciable 
amount of commercial invert sugar. Fiehe's test gave faint reactions in 
five samples. 



Direct polarization: 

Immediate at 20° C 

Constant at 20° C 

Constant at 87° C , 

Invert polarization: 

At 20° C 

At87°C 

Water per cent 

Invert sugar " 

Sucrose " 

Ash *' 

Dextrin " 

Undetermined " 

Free acid as formic ... " 



Cuban. 



— 6 . 1 to — 20. o 

— 8. 6 to— 21. 1 
-{- 6.oto-|-i7.o 

— 8.9 to -23.4 
+ 4.5 to-l-is.4 

16.05 to 27.00 
68.09 to 77.56 

00 00 to 2 99 

0.07 to 0.39 
o. 29 to 3 96 
1.23 to 8.07 

O. GO to 0.43 



Mexican. 



— 7.2 to— 22. 9 

— 8 . 5 tcf — 24 . 2 

+ 3.2 to -I-15.7 

— 9.3 to —26. 1 
+ 2.9 to-Hi3.4 

19.43 to 24.40 
69.27 to 75.04 
o . 00 to 3.98 
o. 13 to 0.58 
0.52 to 3.48 
1.35 to 6.30 
0.07 to 0.35 



Haitian. 



— II .3 to —19.6 

— 12.5 to —20.7 
-I- 4.3 to -j-io.7 



-13.3 to-22.7 

-t- 3.5 to-Hio.i 
18.60 to 22.05 

69.15 1076.73 

o. 00 to 2 . 44 

0.06 to 0.45 

o. 26 to 1.65 

o . 66 to 5 . 46 

0.03 to o. 28 



Dextrorotatory Honey. — The U. S. standards define honey as leevo- 
rotatory, thus excluding the larger part of the Hawaiian product, and also 
unimportant kinds of honey made from certain trees. Pure floral honey 
with no admixture of honeydew is seldom if ever dextrorotory. 

The following are the results obtained by Browne in the examination 
of dextrorotatory honeys: 



* U. S. Dept. of Agric. Bur. of Ciiem., Bui. 154, 1912. 



668 



FOOD INSPECTION AND ANALYSIS. 



Ph 



Hawaiian. 



l3 S o fe 



tn 



Direct polarization at 20° C*. . . 
Invert polarization at 20° C. . . . 
Invert polarization at 87° C. . . . 

Water ; per cent 

Invert sugar " 

Sucrose " 

Ash " 

Dextrin " 

Undertermined " 

Free acid as formic .... " 
Reducing sugar as dextrose, 
per cent 



+ 17.0 
+ 15.0 

+ 35-0 

16.44 

71.69 

0.61 

0.29 

6.02 

4-95 
0.05 



+ 3-6 
- 2.5 
+ 20.9 
17.02 
65.80 
3.10 
C.76 
10.19 

3-13 
0.19 

63.04 



+ 7.8 
+ 3-4 
+ 26.6 
16.05 
65.89 
2.76 
0.78 
12.95 
1-57 



63.12 



+ 11. o 

+ 5.2 
+ 28.6 

13-56 
65.87 

4-31 
0.79 
10.49 
4- 
0.08 

63.11 



+ 17.8 

+ 13-5 
+ 34-8 
15.46 
64.84 

5-27 

1.29 

10.01 

0.15 

62.12 



+ 3 

+ I 

+ 23 

16 

67 

2 



64.96 



+ 5-3 
+ 1.9 
+ 23.4 
17.80 
66.85 
2.41 
0.80 
8.62 

3r52 
0.13 

64.04 



* Constant. 

Adulteration of Honey. — The most common adulterant is commercial 
invert sugar. Cane sugar and glucose were formerly used. Gelatin is 
also said to be used. It appears to be a fact that bees may be made to 
feed upon cane syrup or commercial glucose, if these materials are placed 
in proximity to their hives, so that in some instances the adulterant 
may be supplied through the medium of the bee. Sophisticated honey 
is often put up in tumblers or jars containing pieces of honeycomb^ so 
that presence of the comb is by no means proof of its purity. Comb-honey, 
sold in the frame as sealed by the bees, is never adulterated, except when 
the bees are fed upon glucose or cane sugar. 

Cane Sugar. — The following are typical analyses of honey adulterated 
with cane sugar: 

A. B. c. 

Direct polarization. .. . +34.7 +12 +1.2 

Invert " ....—24 —17.6 —21.5 

Temperature 14° 15° i9-5° 

Sucrose (Clerget) 43.16% 21.8% 17.07% 

Invert sugar 42.48% 60.03% 67.2% 

Water 42-42% 21.15% i5-56% 

Ash .11% 0.06-% 



A strong right-handed polarization before inversion, coupled with a 
left-handed invert reading at 20°, is evidence of adulteration with cane 
sugar, or a product containing cane sugar. 



SUGAR AND SACCHARINE PRODUCTS. 



669 



Honey stored by bees fed on cane sugar is also characterized by its 
right-handed polarization. Although the bee inverts the larger part of 

the cane sugar in its body, this inversion is never as complete as in the 
case of nectar honey. 

Glucose. — The following are typical analyses of honey adulterated 
with commercial glucose: 

A.* B. C. 

Direct polarization. . +147 +66.9 +101. 5 

Invert " .. +135.2 +61.9 + 99.0 

Temperature 18° 20° 22° 

Sucrose (Clerget).... 8.83% 3.76% 0.0% 

Invert sugar 46.18% 74-66% 49.87% 

Water i5-i9% 21.40% 23.7%, 

Ash 0.03% 

Care should be taken not to confuse honeydew honey with honey 
adulterated with glucose. Browne gives the following means of distinction : 
(i) the difference in invert polarization between 20 and 87°, corrected to 
77% invert sugar, (2) Beckman's iodine test (page 673), and (3) the 
Konig and Karsch test (page 674). He also finds the quantity and char- 
acter of the ash, the acidity, and microscopic examination of value. 

The following analyses of mixtures of commercial glucose and honey 
were made by A. H. Bryan. f 



Mixture. 


Constant 


Invert Polarization — 


Polariza- 


Invert Sugar 


Calculated Glucose. 


















100 — 






Direct 
Polariza- 






tion 
Differ- 




After 


Invert 


Invert 
Polariza- 


(Correct- 
ed Polar- 


Glucose 


Honey. 


tion at 

20° c. 


At 20° C. 


At87°C. 


ence 

(87°- 
20°). 


Inver- 
sion. 


Inver- 
sion. 


tion at 
87°- 
1.63. 


(20°C.-h 
17.5)- 


ization 
Differ- 
ence X 


















193. 


100-7- 






















26.7) 


% 


% 


°V. 


°V. 


°V. 


°v. 


% 


% 


% 


% 


% 


100 




+ 153-8 


+ 153-34 


+ 144-32 




30.02 


30-45 


88.5 


88.5 




50 


50 


+ 67.0 


+ 65.67 


+ 73-81 


8.14 


53.67 


54. 5^ 


45-3 


43-1 


56.9 


20 


80 


+ 15-4 


+ 13-42 


+ 33-00 


19.58 


69.00 


70-35 


20.2 


16.0 


19.2 


10 


90 


- 2.4 


- 4.84 


+ 18.59 


23-43 


74.42 


74. li 


II. 4 


6.6 


8.8 


5 


95 


- II-5 


- 14-31 


+ 11.66 


25-96 


75-74 


77.8c 


7-2 


1.6 


3-8 


3 


97 


- 14.2 


- 16.94 


+ 9-13 


26.07 


76.62 


78.01 


5-6 


0.29 


3-7 


2 


98 


— 16.0 


- 18.70 


+ 8.14 


26.84 


76.64 


78-34 


5-0 


0.00 


1.2 


I 


99 


- 18.2 


— 20 . 90 


+ 6.93 


27.83 


77.20 


78.87 


4.2 


0.00 


0.0 




100 


— 19.5 — 22.11 


+ 5-94 


28.05 


77.68 


78-9: 


3-2 


0.00 


0.0 



* Both commercial glucose and added cane sugar. 

t A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 181. 



670 FOOD INSPECTION AND ANALYSIS. 

Commercial Invert Sugar is the most difficult of detection of all the 
adulterants. Herzfeld's process* for the manufacture of invert sugar 
syrups consists in boiling for thirty to forty-five minutes i kilogram of 
refined sugar in 300 cc. of water with i.i gram of tartaric acid. Browne f 
gives the following analysis of the product made by this process: 

Direct polarization at 20° — 6.2 

Constant polarization at 20°. — 9.5 

Invert polarization at 20° —16.9 

Invert polarization at 87° + 4.8 

Water 16.32% 

Invert sugar 73 -3^% 

Sucrose 4 - 3^% 

Ash 0.00% 

. Dextrin 4-86% 

100 .00% 
Acids as formic 0.06% 

This adulterant is best detected by Browne's and Fiehe's tests (page 
674). Ley's test t has value as a confirmatory test, but should be used 
with caution, as American honeys do not react like the European. 

Gelatin is indicated if a precipitate occurs- in the^ diluted sample with 
a solution of tannic acid. 

ANALYSIS OF HONEY. 

Preparation of Sample. — In the case of strained honey, stir with a rod, 
till any separated sugars are evenly distributed throughout the mass, or, 
if the honey has become solidified wholly or in part by crystallization, use 
a gentle heat on a closed water-bath to restore to it fluid form. 

In the case of comb honey, cut with a knife across the top of the comb 
if sealed, and separate completely from the comb by straining through 
a 40-mesh sieve. 

Determination cf Moisture. §— Weigh 2 grams into a flat- bottom 
metal dish 2j inches in diameter, which, together with 10 to 15 gram.s 



1 



* Zeits. ver. d. Zucker-Ind., 31, p. 1988. 

t Loc. cit., p. 64. 

X Pharm. Zeits., 47, 1902, p. 603. 

§ Browne, U. S. Dept. of Agric, Bur. of Chem., Bui. no, p. 18. 



SUGAR AND SACCHARINE PRODUCTS.. 671 

of fine quartz sand and a short stirring rod, has been previously tared, 
add 5 to lo cc. of water, stir until the whole has been thoroughly incor- 
porated, and dry to constant weight at 65 to 70° C. in a vacuum oven. 
Honeys of high purity usually dry in twelve hours, while those of the honey- 
dew class, rich in dextrin and gum, require thirty-six hours, or longer. 

Determination of Ash. — See page 644. 

Polarization. — Direct and Invert at 20° C. — Proceed as directed under 
molasses (page 644), except that only alumina cream is used as a clarifier. 
To destroy birotation add a drop or two of ammonia before making up 
to the mark.* 

Invert at 87° C. — Invert a half normal portion in the usual manner in 
a loo-cc. flask, cool, add a few drops of phenolphthalein and enough 
sodium hydroxide to neutralize; discharge the pink color with a few drops 
of dilute hydrochloric acid, add from 5 to 10 cc. of alumina cream, make 
up to the mark and filter. Polarize in a 200-mm. tube at 87°, and multiply 
reading by 2. 

Polarization at the temperature of 87° can most readily be effected 
by the use of a water-jacketed tube, as shown in Fig. iii. An all-metal 
tube, the interior of which is heavily gold-plated to avoid corrosion by 
acid, is preferable to one in which the inner tube is glass with a metal 
jacket, as in the latter leaky joints are liable to occur, due to uneven 
expansion. A tubulure is provided in the outer tube for a thermometer, 
so that the exact temperature may be noted. A tank of boiling water 
placed on a shelf above the polariscope is connected by rubber tubing 
with the jacketed tube as it rests in the polariscope, as shown in Fig. iii. 

Determination of Reducing Sugars. — Determine by Allihn's method 
(page 632) in an aliquot of 25 cc. of a solution obtained by making 10 cc. 
of the solution prepared for polarization up to 250 cc. If desired the 
sugar may be determined by the volumetric Fehling process (page 615). 

The reducing sugars may be calculated as dextrose as obtained from 
Allihn's table, or as levulose by multiplying the dextrose by 1.044. 

Determination of Levulose. — Wilefs Method.-f — This may be calcu- 
lated approximately by the following formula : 

100(1.0315^ —a) 100(1.0315/! —a) 
(2.3919)26 62.19 ' 

* Fruhling, Zeits. offentl. Chemie, 4, 1898, p. 410. 

t Principles and Practice of Agricultural Analysis, 1897, III, p. 267. Browne, loc. cit, 
p. 17. 



672 FOOD INSPECTION AND ANALYSIS. 

in which / = levulose, a = the direct polarization at 20° of a solution of the 
normal quantity of honey made up to 100 cc. at 20°, and A = the direct 
polarization of the same solution at 87° C, 2.3919 = the variation in 
polarization of i gram of levulose in 100 cc. of solution between 20 and 
87° C, and 1.0315 = the factor for converting the volume of the solution 
at 20° into that at 87° C. 

Determination of Dextrose.* — Multiply the percentage of levulose 
as obtained in the preceding section by 0.915, thus obtaining the equivalent 
dextrose, and subtract this from the per cent of reducing sugars expressed 
as dextrose. 

Determination of Sucrose. — Owing to the inaccuracies of Clerget's 
method as applied to honey, Browne recommends the following : Neutralize 
the free acid of 10 cc. of the solution used for invert polarization with 
sodium carbonate, make up to 250 cc. and determine the reducing 
sugars by Allihn's method. Subtract from the invert sugar thus obtained 
the invert sugar found before inversion, and multiply the difference by 
0.95. 

Determination of Dextrin. — Browne's Method.^ — Weigh 8 grams of 
honey directly into a loo-cc. flask, add 4 cc. of water, and finally with 
continued agitation sufficient absolute alcohol to fill to the mark. Shake 
thoroughly and allow to stand twenty-four hours, or until the dextrin is 
deposited on the bottom and sides of the flask and the liquid is perfectly 
clear. Decant on a filter and wash the precipitate in the flask with 10 cc. 
of cold 95% alcohol, pouring the liquid finally on the filter. Dissolve 
the precipitate in the flask and on the filter in a little boiling, distilled 
water, collecting the solution in a tared platinum dish. E\aporate the 
liquid, and dry to constant weight at 100° C. If the alcohol precipitate 
is considerable, it should be dried at 70° C. in vacuo. After weighing, 
dissolve in water and make up to a definite volume according to the 
weight as follows : 

Residue, grams. 0-0.5 0.5-1.0 i. 0-1.5 i-5~2.o 2.0-2.5 2.5-3.0 
Volume, cc. . . . 50 too 150 200 250 300 

Filter, determine invert sugar and sucrose in aliquots by copper reduction 
before and after inversion, and subtract the sum of these sugars from the 
total alcohol precipitate. 

* Browne, loc. cit., p. 17. Jour. Am. Chem. Soc, 28, 1906, p. 446. 



SUGAR AND SACCHARINE PRODUCTS. 673 

Determination of Acids. — Dissoh'e lo grams of the honey in water 
and titrate with tenth-normal sodium hydroxide, using phenolphthalein 
as indicator. Express result as formic acid. 

Beckman's Test for Glucose.*— Treat a mixture of equal parts of 
honey and water with a solution of iodine in potassium iodide. If glucose 
is present, a red or violet color (due to erythro- or amylo-dextrin) appears, 
the shade and intensity depending on the nature and amount of the 
glucose present. 

Determination of Commercial Glucose in Honey. — Except for rough 
work, the method described on page 651 for calculating the per cent of 
commercial glucose from the sucrose and from the direct polarization is 
not recommended for use with honey and other products wherein the invert 
sugar is so large as to considerably affect its accuracy. In this case, it 
is best after inversion to polarize the sample at 87° C, the temperature at 
which the reading due to invert sugar would theoretically be o. At 
this temperature, any considerable right-handed polarization can be 
accounted as due to commercial glucose. (See page 671.) 

As in the case of molasses, the writer advocates assuming 175° as the 
direct polarization of the glucose used, this being about the maximum 
reading for a normal solution of 42°- Be. glucose. Lythgoe has shown 
that in polarizing at high temperatures samples of saccharine products 
containing commercial glucose, certain precautions have to be observed 
not necessary when cane or invert sugar are the only sugars present. 
Thus, a normal solution of glucose, when polarized at 87° C, has a lower 
reading than in the cold, the difference being doubtless due partly at 
least to the expansion of the liquid. Again, on subjecting a normal 
solution of glucose to inversion with acid, as in Clerget's process, and 
heating to 87° C, it will be found impossible to get a constant reading, 
but the reading will drop rapidly, due to a partial hydrolysis of the 
maltose or dextrin. 

In honey and other preparations containing much invert sugar and 
commercial glucose, it is best to proceed as follows: Divide the polariza- 
tion at 87° by i63°t and multiply the result by 100 for the percentage of 
commercial glucose in terms of glucose polarizing at 175°. It should be 



* Zeits. Anal. Chem., 35, 1896, p. 267. 

fThe true polarization at 87° C. of a normal solution of glucose subjected to inversion 
and neutralization as above (but without the use of the clarifier), will be about 93% that 
of the direct polarization of the sample in the cold. Hence 175X0.93 = 162.7. 



674 FOOD INSPECTION AND ANALYSIS. 

borne in mind that the results by even this method are only approximate, 
as genuine honey is more or less dextrorotatory at 87° C. 

The foilowincr formula is used by European chemists: G = -^, in 

1.93 

which G=the per cent of commercial glucose, and & = the polarization 

after inversion at 20° C. 

Browne's Test for Commercial Invert Sugar.* — Reagent. — This 
should be freshly prepared each time before using. Shake 5 cc. of c. p. 
anilin with 5 cc. of water, and add sufficient glacial acetic acid (2 cc.) to 
just clear the emulsion. 

Process. — Treat 5 cc. of a i : i solution of the honey in a test-tube 
with I to 2 cc. of the anilin reagent, allowing the latter to flow down the 
walls of the tube so as to form a layer upon the honey solution. If, when 
the tube is gently agitated, a red ring forms beneath the anilin solution, 
this color becoming gradually imparted to the whole layer, artificial 
invert sugar is present. This reaction is due to furfural formed during 
the l^^^h temperature employed in the commercial processes of inversion. 
Boiling genuine honey also causes the formation of furfural, but this treat- 
ment impairs the flavor and is probably never practiced, 

Fiehe's Test for Commercial Invert Sugar Modified by Bryan. f — 
Place 10 cc. of a 50% solution of the sample in a test tube, add 5 cc. of ether, 
shake vigorously, allow to stand until the ether is clear, then transfer 2 cc. 
to a small test-tube and add a large drop of a solution of i gram of resorcin 
in 100 cc. of hydrochloric acid and shake. A cherry-red color indicates 
commercial invert sugar while a faint orange to rose color, disappearing 
after a short time, may be due to heating of the honey. 

Ley's Ammoniacal Silver Nitrate Test % is not so reliable as the two 
preceding tests. 

Distinction of Honeydew and Glucose Honeys. — Method of Kdnig 
and Karsch.^ — Dissolve 40 grams of honey in a cylinder in water, and 
make up to 40 cc. Transfer 20 cc. of the homogeneous solution to a 
250-cc. flask and fill to mark with absolute alcohol with slow addition and 
constant shaking, and then allow to stand two or three days, with occasional 
agitation. At the end of this time all the dextrin has settled out. After 
shaking the solution, filter and evaporate ico cc. of the filtrate until free 

* U. S. Dept. of Agric, Bur. of Chem., Bui. no, p. 68. 

t Zeits. angew. Chem., 21, i8q8, p. 2315; Bur. of Chem., Bui. 154, p. 15. 

JPharm. Ztg., 1902, p. 603; Zeits. angew. Chem., 1907, p. 993. 

§ Zeits. anal. Chem., 34, 1895, p. i. U. S. Dept. of Agric, Bur. of Chem., Bui. no, p. 63. 



SUGAR AND SACCHARINE PRODUCTS. 



675 



from alcohol. To the liquid residue add a little subacetate of lead and 
sodium sulphate, make up to 20 cc. with water, and polarize the filtered 
solution. Dextrorotatory natural honeys show by this method a laevo- 
rotation; honeys adulterated with dextrose of glucose to the extent of 
25% or more, a dextrorotation. In case the honey contains a large 
amount of sucrose, the solution should be inverted with hydrochloric acid 

before polarizing. 

BEESWAX.— The purity of beeswax is best established by determming 
its melting-point, its specific gravity, its saponification equivalent, and 
its refractometric reading. The melting-point of pure wax is about 
64° C, while that of paraffin, its chief adulterant, is from 52 to 55° C. 
Its saponification equivalent should be from 87.8 to 107, while that of 

paraffin is o. 

Method of Determining Specific Gravity of Beeswax."^— V\d.ce a weighed 
rod of the wax, about i to 1.5 cm. long by 0.5 cm. diameter, in an accurately 
marked 50 cc. flask, and run in water from a burette till the water level 
reaches the mark. 50 cc. minus the burette reading represent the vol- 
ume occupied by the wax. The rod should be made to lie flat on the 
bottom of the flask, so that the incoming water will force its end against 
the sides and prevent the end from rising above the mark. The weight 
of the rod, divided by its volume gives its specific gravity. The specific 
gravity of various mixtures of wax of 0.969 specific gravity and paraffin 
of 0.871 are given in the following table, prepared by Wagner, so that 
from the specific gravity of the mixture the percentage of paraffin can be 
calculated : 



Wax 
(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


Wax 
(Percentage). 


Paraffin 
(Percentage). 


Specific 
Gravity. 


25 

50 


100 
75 

50 


.871 

-893 
.920 


75 

80 

100 


25 
20 


.942 
.948 
.969 



The Refractometer Reading is most useful in establishing the purity 
of wax. Observations with this instrument are best made at 65° and 
great care should be taken in the case of the Zeiss butyro-refractometer 
not to exceed this temperature, or injury to the instrument may result. 

The Abbe refractometer may be used with perfect safety and, when 
available, is to be preferred for the examination of beeswax. Many 



* Gawalowski, Chem. CentrbL, 1890, p. 502. 



676 



FOOD INSPECTION AND ANALYSIS. 



food laboratories are, however, not equipped with the Abbe, but nearly 
all find the butyro-refractometer indispensable. The latter instrument 
was primarily designed for such substances as butter and lard, so that the 
manufacturers did not intend it to be subjected to as high a temperature 
as 65°. _ They have, however, assured the author that if care be taken 




Fig. III. — Apparatus for Polarizing at High Temperatures. 

to bring the temperature very slowly and gradually to the required degree 
65°, and to avoid also sudden cooling, the cement that secures the prisms 
in place will not be appreciably affected; otherwise cracking or loosening 
of the cement would be liable to occur after a time. 

At 65° C. pure beeswax should have a reading on the butyro-refrac- 
tometer of 30 to 31.5,* while that of paraffin is from 11 to 14.5.! 



* wz>, 1.4452 to 1.4463. 
t«z>, 1.4310 to 1.4335- 



SUGAR AND SACCHARINE PRODUCTS. 677 



CONFECTIONERY. 

The composition of confectionery is more complex than that of the 
saccharine products hitherto consideredo As a rule, cane sugar, or one 
of its products, as molasses, forms the basis of most of the confections. 
Commercial glucose is also a common ingredient, while a large variety 
of such materials as eggs, butter, chocolate, various flavoring extracts, 
spices, nuts, and fruits, enter into the composition of confectionery. 

U. S. Standard Candy is candy containing no terra alba, barytes, 
talc, chrome, yellow, or other mineral substances or poisonous colors or 
flavors, or other ingredients injurious to health. 

Adulteration. — Of late the adulteration of confectionery has been 
held largely in check by the National Confectioners' Association of the 
United States, which has fixed high standards of purity, and has been 
very zealous in restricting the use of harmful adulterants. 

Commercial glucose is not regarded as an adulterant of confectionery 
by the above-named association and by but few food authorities. On the 
contrary, any ingredient, other than color, that has no food value, may 
logically be considered as an adulterant. Under this head are included 
such substances as paraffin, as well as make-weight mineral matters, such 
as terra alba, talc, or calcium sulphate. 

B, H. Smith * has called attention to the presence of arsenic in shellac 
used to coat certain kinds of confectionery. 

Colors in Confectionery. — A very wide range of colors is necessarily 
employed in the manufacture of confectionery, and the almost endless 
variety of coal-tar dyes now available lend themselves most readily to 
the confectioner's needs. Elsewhere, under " colors," lists of injurious 
and non-injurious dyes are given as compiled by the National Confec- 
tioners' Association, though it is not always readily apparent how the lines 
are drawn. 

The tinctorial power of these dyes is so high that the actual amount 
of substance contained in a thin coating of the color on the outside of the 
candy is exceedingly small, so that it is doubtful whether serious cases of 
injury have ever arisen from their use. 

This was not the case formerly when such poisonous mineral pigments 
as chromate of lead were frequently used. 

* U. S. Dept. of Agric, Bur. of Chem., Circ. 91, 1912. 



678 FOOD INSPECTION AND ANALYSIS 



ANALYSIS OF CONFECTIONERY. 

The following methods are largely those submitted by the author 
as provisional methods of the A. O. A. C.:* 

(i) Products of Practically Uniform Composition Throughout. — 
(a) Lozenges and Other Pulverizable Products. — Grind in a mortar or 
mill to a fine powder. For total solids, weigh from 2 to 5 grams of the 
powdered sample in a tared platinum dish, and dry in a McGill oven 
to constant weight. 

For Ash, ignite the residue from total solids in the original dish, 
observing the precautions given under sugar (page 609), and molasses 
(page 644). 

(b) Semi-plastic, Syrupy, or Pasty Products. — Weigh 50 grams of 
the sample into a 50-cc. graduated flask, mix thoroughly or dissolve, 
if soluble in water, and fill to the mark. Be sure that the solution is 
uniform, or, if insoluble material is present, that it is evenly mixed by 
shaking before taking aliquot parts for the various determinations. For 
total solids and ash, measure 25 cc. of the above solution or mixture into 
a tared platinum dish, and proceed as directed under (a). 

(2) Confectionery in Layers or Sections of Different Composition. — 
When it is desired to examine the different portions separately, they 
should be separated mechanically with a knife, when possible, and treated 
as directed under (i). 

(3) Sugar-coated Fruit, Nuts, etc. — In case of a saccharine coating 
inclosing fruit, nuts, or any less readily soluble material, dissolve or 
wash off the exterior coating in water, which may, if desired, be evaporated 
to dryness for weighing, and proceed as in (i). 

(4) Candied or Sugared Fruits. — Proceed as in the examination of 
fruits (Chapter XXI). 

Detection of Mineral Adulterant.— As in the case of molasses, a 
considerable quantity, say 100 grams, should be reduced to an ash for 
examination for mineral adulterants, such as talc, calcium sulphate, and 
iron oxide, which are detected by regular qualitative tests. 

Detection of Lead Chromate. — Fuse the ash in a porcelain crucible 
with a mixture of sodium carbonate and potassium chlorate, boil the 
fused residue with water, neutralize with acetic acid, filter, and treat the 
filtrate with barium chloride or lead acetate solution. A yellow pre- 

* U. S. Dept. of Agric; Bur. of Chem., Bui. 65, p. 44. 



SUGAR AND SACCHARINE PRODUCTS. 679 

cipitate indicates a chromate. Treat the insoluble part of the fusion 
with nitric acid, and test for lead in the usual manner. 

If a drop of ammonium sulphide be applied to a piece of confectionery 
colored with lead chromate, it will produce a black coloration. 

Determination of Ether Extract. — The ether extract includes the fat 
derived from chocolate, eggs, or butter, as well as any paraffin present. 
Measure 25 cc. of the 2o7o solution (i) (b) (page 678) into a very thin, 
readily frangible glass evapora ting-shell {Hoffmeister's Schakhen), con- 
taining 5 to 7 grams of freshly ignited asbestos fiber; or, if impossible to 
thus obtain a uniform sample, weigh out 5 grams of the mixed, finely 
divided sample into a dish, and wash with water into the asbestos in the 
evaporating-shell, using, if necessary, a small portion of the asbestos 
fiber on a stirring-rod to transfer the last traces of the sample from dish 
to shell. Dry to constant weight at 100°, after which cool, wrap loosely 
in smooth paper, and crush into rather small fragments between the 
fingers, carefully transferring the pieces with the aid of a camel's-hair 
brush to an extraction-tube, or to a Schleicher and Schull cartridge for 
fat extraction. Extract with anhydrous ether or with petroleum ether in 
a continuous extraction apparatus for at least twenty-five hours. Trans- 
fer the solution to a tared flask, evaporate the ether, dry in an o\'en at 
100° C. to constant weight, and weigh. 

More recently the association adopted the Rose-Gottlieb method for 
butter scotch. 

Determination of Paraffin. — Add to the ether extract in the flask, as 
above obtained, 10 cc. of 95% alcohol, and 2 cc. of i : i sodium hydroxide 
solution, connect the flask with a reflux condenser, and heat for an hour 
on the water-bath or until saponification is complete. Remove the con- 
denser, and allow the flask to remain on the bath till the alcohol is evapo- 
rated off, and a dry residue is left. Treat the residue with about 40 cc. 
of water, and heat on the bath, with frequent shaking, till everything 
soluble is in solution. Wash into a separatory funnel, cool, and extract 
with four successive portions of petroleum ether, which are collected in 
a tared flask or capsule. Remove the petroleum ether by evaporation, and 
dry in the oven to constant weight. 

It should be noted that any phytosterol or cholsterol present in the 
fat would come down with the paraffin, but the amount would be so 
insignificant that, except in the most exacting work, it may be disregarded. 
The character of the final residue should, however, be confirmed by 
determining its melting-point and specific gravity, and by subjecting it 



680 FOOD INSPECTION AND ANALYSIS. 

to examination in the butyro-refractometer. The melting-point of par- 
alTm is about 54.5° C. ; its specific gravity at 15.5° C. is from 0.868 to 0.915, 
and on the butyro-refractometer the reading at 65° C. is from 11 to 

I4-5- 

Determination of Starch. — Measure gradually 25 cc. of a 20% aqueous 

solution or uniform mixture of the sample into a hardened filter or Gooch 
crucible, or transfer by washing 5 grams of the finely powdered substance 
to the filter or Gooch, and allow the residue on the filter to become air- 
dried. Extract with five successive portions of 10 cc. of ether, then 
wash with 150 cc. of 10% alcohol, and finally with 20 cc. of strong alcohol. 
Transfer the residue to a large flask and boil gently for four hours with 
200 cc. of water and 20 cc. of hydrochloric acid (specific gravity 1.125), 
the flask being provided with a reflux condenser. Cool, neutralize with 
sodium hydroxide, add 5 cc. of alumina cream, and make up the volume 
to 250 cc. with water. Filter and determine the dextrose in an aliquot 
part of the filtrate by any of the various Fehling methods. The weight 
of the dextrose multiplied by 0.9 gives the weight of the starch. 

Polarization of Confectionery. — As a clarifier use either alumina 
cream or subacetate of lead, according to the nature and capacity of the 
sample. Ordinarily alumina cream is best, but in dark-colored samples, 
or those in which molasses has been used, it is sometimes necessary to 
employ the subacetate. When starch is absent, and the sample is practi- 
cally soluble, polarize and invert in the usual manner (page 610). Where 
considerable starch or insoluble matter is present, use the double-dilution 
method of Wiley and Ewell (page 650), thus making due allowance for 
the volume of the precipitate. 

Ca}2e sugar, invert sugar, and dextrin, are determined as directed 
for honey. 

Commercial glucose is roughly determined by polarizing the sample 
at 87° C., as in the case of honey (page 671). 

Confectionery is made in such a wide variety of forms, and these differ 
in consistency to such an extent that commercial glucose of all available 
degrees of density can be utilized to advantage in one product or another. 
In this respect confectionery is unlike honey and molasses, wherein a 
fairly uniform grade of commercial glucose is necessarily used for 
mixing, this grade being naturally selected with reference to its similarity 
in density to the molasses. On this account the glucose factor used 
for honey and molasses (175) may in some varieties of confectionery be 
too high. 



SUGAR AND SACCHARINE PRODUCTS. 681 

Determination of Alcohol in Syrups Used in Confectionery. — (Brandy- 
drops.) — Open each drop by cutting off a section with a sharp knife, and 
collect in a beaker the syrup of from 15 to 25 of the drops, which will 
usually yield from 30 to 50 grams of syrup. Strain the syrup into a 
tared beaker through a perforated porcelain filter-plate in a funnel to 
separate from particles of the inclosing shell, and ascertain the weight 
of the syrup. Wash into a distilling-flask, dilute with half its volume 
of water, and distil off into a tared receiving-flask a volume equal to the 
original volume of syrup taken. Ascertain the weight of the distillate 
and its specific gravity by means of a pycnometer. Multiply the per- 
centage by weight of alcohol corresponding to the specific gravity, as 
found in the tables on page 690 et seq., by the weight of the distillate, and 
divide this by the weight of syrup taken. The result is the per cent by 
weight of alcohol in the syrup. 

Detection of Colors. — It is sometimes necessary to macerate a con- 
siderable mass of the material to remove the color, which is, however, 
in the majority of cases readily soluble. The insoluble colors are nearly 
all mineral pigments to be looked for in the ash, as in the case of chromate 
of lead (page 678). Frequently the coloring matter is confined to a thin 
outer layer, which is readily washed off. 

The solution of the dyestuff is examined as directed under colors. 

Detection of Arsenic. — Arsenic may be present through impure glu- 
cose, shellac, or coloring-matter. If the color is confined to an exterior 
coating, this should be washed ofT and examined. If distributed through 
the mass, a solution of the whole should be taken. Examine for arsenic 
by the Gutzeit or Marsh method, as directed on pages 63 to 66. 



CHAPTER XV. 

ALCOHOLIC BEVERAGES. 

Alcoholic Fennentation. — In a broad sense all alcoholic liquors are 
saccharine products, in that they are essentially the result of the fermen- 
tation of sugars. In the case of fruits, the sugars already exist as such 
in their juices, which, when expressed, almost immediately begin to undergo 
spontaneously the process of alcoholic fermentation, through the agency 
of the enzyme zymase of the wild yeasts introduced with the skins of the 
fruit or from the air. The reaction is as follow^s: 

(l) C6Hi206=2C2H60 + 2C02. 

Dextrose or Alcohol Carbon 

Levulose dioxide 

While the foregoing reaction applies to the dextrose and levulose 
of invert sugar, which sugar usually predominates in fruit juices, being 
formed by the inversion of sucrose, the reaction with sucrose itself, which 
is not directly fermentable, involves a preliminary inversion through the 
agency of the enzyme invertase present in yeast, thus: 

(2) Ci2H220n+H20=C6Hi206+C6Hi206. 

Sucrose Dextrose Levulose 

In the case of grains the process is more complex, involving hydroliza- 
tion of the starch into maltose through the action of the diastase of malt 
and the further hydrolization of the maltose, which, like sucrose, is not 
directly fermentable, into dextrose by means of an enzyme of yeast known 
as maltase or maltoglucase. These reactions may be expressed as fol- 
lows: 

(3) 2C6Hio05 + H20=Ci2H220ii 

Starch Maltose 

(4) Ci2H220n +H20= 2C6H12O6 

Maltose Dextrose 

682 



ALCOHOLIC BEVERAGES. 683 

The above reaction, No. i, illustraUng the sphtting up of grape sugar 
into alcohol and carbon dioxide, does not represent the practical yield 
of alcohol under ordinary condi.ions that occur in vinous fermentation, 
for, as a matter of fact, instead of 51.11 parts of alcohol and 48.89 parts 
carbon dioxide, which would theoretically result as above from the fer- 
mentation of 100 par.s of dextrose, only about 95% of the theoretical 
yield can be obtained, so that in practice it is possible to form but about 
48.5% alcohol and 46.5% carbon dioxide. The balance, amounting 
to some 5%, consists chiefly of glycerin, succinic acid, and traces of 
various compounds, including some of the higher-boiling alcohols (propyl, 
butyl, and amyl) and their ethers, which form the fusel oil of the dis- 
tilled liquors. 

Vinous fermentation takes place most readily in slightly acid liquids, 
at a temperature ranging from 25° to 30° C. 

It is convenient to divide alcoholic beverages into two main groups, 
first the fermented and second the distilled liquors. The fermented 
liquors naturally subdivide themselves into (a) the products of the direct 
spontaneous fermentation of saccharine fruit juices, such, for example, 
as those of the apple and the grape, to form cider and wine respectively, 
and (b) the mal ed and brewed liquors,, such as beer and ale, produced 
by the conversion of the starch of grain into sugar, and the final alcoholic 
fermentation of the latter. 

The distilled liquors include such products as whiskey, brandy, rum, 
and gin, wherein alcoholic infusions prepared by previous fermentation 
in various ways are further subjected to distillation. 

Alcoholic Liquors and State (or Municipal) Control. — The mere 
adulteration of liquors does not constitute the only feature which brings 
them within the scope of the public analyst's work and renders them 
especially amenable to stringent laws. Indeed, it is often a far more 
important ques ion for the analyst to decide by his results whether or 
not the samples submitted to him, by pohce seizure or otherwise, are 
sold in violation of the regulations in force in his particular locaHty govern- 
ing the liquor traffic. 

A common regulation in no-license localities fixes the maximum per 
cent of alcohol which shall decide whether or not a liquor is legally a 
temperance drink, and can be sold as such wilh impuni.y. From ils low 
content in alcohol, an analyst's findings regarding a certain sample may 
exonerate the dealer suspected of violating this law, while yet by the 
very reason of its being low in alcohol the same sample would be placed 



684: FOOD INSPECTION AND ANALYSIS. 

in the adulterated list as regards non-conformance to a standard of purity. 
While the raising of revenue is one purpose for the existence of these 
laws bearing on liquor license, an equally important object sought to be 
gained is doubtless the repression of intemperance. 

Toxic Effects. — A popular impression seems to exist that the toxic 
effects of an adulterated liquor are far worse from a temperance stand- 
point than those of a sample of good standard quality, and it is a common 
experience of the public analyst to have submitted to him by well-mean- 
ing temperance advocates samples which are alleged to have caused 
the worst forms of intoxication, and are thus suspected of being impure. 
As a matter of fact the chief adulterants of liquors are water, sugar, and, 
in the case of beer, various bitter principles and vegetable extractives, 
none of which are on record as being in themselves actively toxic* 

Alcohol is the one ingredient of liquor which, more than any other, 
produce^ a marked physiological effect. Many liquors, especially those 
of the distilled variety classed as adulterated, are so considered by reason 
of their low alcoholic content through watering or otherwise, hence this 
commonest form of adulteration, far from being detrimental in itself, is 
actually helpful to the temperance cause. 

Details of Liquor Inspection. — The same precautions should be 
carefully observed by officers making seizures of liquors for analysis, 
as by food inspectors, regarding safe delivery of the samples to the 
analyst. The following instructions are circulated by the State Board 
of Health of Massachusetts, which has in charge the inspection of liquors, 
concerning the taking of samples in that state and the transmission to 
the analyst: 

DIRECTIONS FOR TAKING SAMPLES FOR ANALYSES. 

The officer making a seizure, or taking samples of beer, should note 
at the time of such seizure the general appearance of the liquor, — as to 
whether it is clear or cloudy, whether it is still or has a strong head. 

If the liquor is in bottles, take at least one pint bottle; if in barrels, 
draw a pint bottle from each. Request the owner to seal each sample 
taken. If the bottles have cork stoppers, cut the stoppers off level with 
the top of the bottle and cover with w^ax; if with patent stoppers, a little 
wax placed upon the wire at the point where it lays against the neck of 
the bottle is sufficient. If the owner refuses to seal it, then the officer 

* The writer refers to substances intentionally added, and not to accidental impurities, 
such as arsenic, etc., that are occasionally found. 



ALCOHOLIC BEVERAGES. 685 

should seal it in his presence, caUing his attention to the fact. Before 
leaving the premises, place upon the bottle a label or tag, with the date, 
the name of the owner, and the name of the officer upon it, and also the 
name of the town or city. Then place in a box, with the certificate 
required by law, and forward without delay to the analyst. 

FORM OF LABEL. , 



Town , 

Date of seizure 19 

Owner 

Kind of liquor 

Brewer 



Accompanying each sample is a certificate like the following, the 
first part of which is filled out and figned by the officer, while the second 
part, containing the data of analysis, is filled out and signed by the analyst 
and returned by him to the officer. Such a certificate is nearly always 
accepted as evidence in court without the personal appearance of the 
analyst. 

ss 19 , 

To the State Board of Heahh: 

I send herewith a sample of 

taken from liquors seized by me 19 . 

Ascertain the percentage of alcohol it contains, by volume, at sixty 
degrees Fahrenheit, and return to me a certificate herewith upon the 
annexed form. 
Seized from 



Officer. 

COMMONWEALTH OF MASSACHUSETTS. 

No 

Office of the State Board of Health. 

Boston, 19 . 

This is to certify that the received by me 

with the above statement contains per cent of alcohol, 

by volume, at sixty degrees Fahrenheit. ^°'^ 

Received : 19 . 

Analysis made 19 . 



[seal.] Analyst State Board of Heahh, 



FOOD INSPECTION AND ANALYSIS. 



A convenient method for recording analyses is by the employment 
of numbered library cards, which bear the same number as the certificates 
and are kept by the analyst. 

The following is a convenient form: 



No Analyzed 

County Wt. flask and ale 

City or town Wt. flask 

Ofiicer Wt. ale 

Defendant Sp. gr. ale. (60°) 

Address Per cent aleohol 

Kind of liquor Reported 

Seized 

Received 

How delivered 

Sealed 

Condition 

Kind of bottle 

Registered 

METHODS OF ANALYSIS COMMON TO ALL LIQUORS. 

Specific Gravity. — This should be taken at 15.6° or calculated to 
that temperature. The most convenient mode of procedure is to bring 
the temperature of the sample somewhat below that point by allowing 
the flask containing it to stand in cold water, and to have everything in 
readiness to make the determination when 15.6° temperature has been 
reached, either by the hydrometer spindle in a glass cylinder, by the 
Westphal balance, or by the pycnometer. The latter is by far the most 
accurate, especially if it is of the form which is fitted with a thermometer- 
stopper. 

Detection of Alcohol. — It is rarely necessary to make a qualitative 
test for alcohol in liquors, since it is almost invariably present even in 
many of the so-called temperance drinks, at least in small amount. 
Indeed in many localities a beverage is legally a temperance drink that 
contains not more than 1% alcohol by volume. 

The Iodoform Test. — Alcohol, when present in aqueous solution to 
the extent of o.i% or more, may be detected by the iodoform test. The 
solution is warmed in a test-tube with a few drops of a strong solution 
of iodine in potassium iodide, after which enough sodium hydroxide 
solution is added to nearly decolorize. On standing for some time a 
yellow precipitate of iodoform will appear if alcohol be present, or at 
once if there is a considerable amount, and the characteristic odor of 
iodoform will be rendered apparent, "even when the precipitate is so slight 
as to be almost imperceptible. This iodoform precipitate is crystalline, 
showing under the microscope as star-shaped groups or hexagonal tablets. 



ALCOHOLIC BEVERAGES. 687 

It should not be forgotten thai other substances than alcohol give the 
reaction, as lactic acid, acetone, and various aldehydes and ketones. 

Pure methyl or amyl alcohol or acetic acid do not thus react. 

Bcrthelot recommends benzoyl chloride as a reagent for detecting 
alcohol. By warming a mixture of a few drops of benzoyl chloride with 
the solution to be tested, and adding a little sodium hydroxide, ethyl 
benzoate is formed, recognizable by its distinctive odor. This reaction 
is delicate to o.i% alcohol. The presence of other alcohols than ethyl 
produces ethers of characteristic odor. 

Hardy's Test jor Alcohol consists in shaking the aqueous solution 
with some powdered guaiacum resin, filtering, and adding to the filtrate 
a little hydrocyanic acid and a drop of dilute copper sulphate sohition. 
A blue coloration considerably deeper than that due to the copper salt 
is indicalive of alcohol. 

Methyl Alcohol in spirits is tested for as described on pp. 781-784. 

Determination of Alcohol. — In the case of carbonated liquids it is 
necessary to first expel the free carbon dioxide, which is readily accom- 
plished by pouring the liquor back and forth from one beaker to another, 
from time to time removing the excess of froth from the top of the vessel 
by the aid of the hand. Or, the sample may be shaken vigorously in a 
large separatory funnel, and the still liquor drawn off from below the 
froth, repeating the operation several times if necessary. In either 
case the mechanical treatment should be continued till the liquor is com- 
paratively quiet and free from foam. 

(i) By Distillation. — This is by far the most accurate method of 
determining alcohol, and should be carried out in all cases where any 
legal controversy is apt to be involved. Into a flask of 250 to 400 cc. 
capacity introduce a convenient quantity of the liquor, which should be 
accurately weighed or measured, according to whether the percentage 
by weight or measure is desired. The following are suitable quantities* 
Distilled liquors, 25 grams or cc; cordials, 25 to 50 grams or cc; wineSj 
ciders, and malt liquors, 100 grams or cc. In the case of wines or 
ciders which have undergone acetic fermentation, add o.i to 0.2 gram of 
precipitated calcium carbonate or neutralize with standard alkali. 

Dilute the liquid to 150 cc. and distil into a loo-cc flask. Nearly 
all alcoholic liquors, if comparatively free from carbon dioxide, will 
boil without undue frothing or foaming. New wine will occasionally 
give trouble in this regard, but foaming may usually be prevented in this 



688 FOOD INSPECTION AND ANALYSIS. 

case by the addition of tannic acid. In case of wine, cider, and beer 
all the alcohol will have passed over in the first 75 cc. of the distillate, 
or three-fourths the original measured volume, but with distilled liquors 
high in alcohol the process had better be continued till nearly 100 cc. or 
the original volume taken have passed over. If the condenser is of glass, 
one can observe when all the alcohol has been distilled over, for the reason 
that the mixed alcohol and water vapors in the upper portion of the con- 
denser present a striated or wavy appearance, readily apparent so long 
as the alcohol is passing over, while after all the alcohol has been distilled, 
the condenser-tube appears perfectly clear. The distillation is thus 
continued for some time after this striated appearance has ceased. The 
distillate in the receiving glass is finally made up to the mark or to the 
original volume of the liquor taken. Strictly speaking, the measure- 
ments before and after distillation should be made at 15.6° C, but, except- 
ing in case of distilled liquors, no appreciable error results from making 
both measurements at the same or room temperature. Another precau- 
tion formerly thought necessary was to have the delivery-tube from the 
condenser pass below the level of a little water in the receiving-flask 
from the start, but equally accurate results have been obtained by simply 
allowing the end of the condenser-tube to enter the narrow-necked flask. 

Fig. 112 shows a bank of six stills of the kind used in the author's 
laboratory for alcohol determination in liquors. In each still the verti- 
cal glass worm-condenser, the round-bottomed distilling-flask, and the 
lamp, are supported by rings held by a single upright rod. The receiving 
flask is readily connected wi.h the condenser by means of a single bent 
tube provided with a rubber stopper. The cold-water pipe supplying 
the condensers is shown at the top, and the gas-supply pipe at the bottom. 

The distillate, made up to 100 cc, is thoroughly shaken and its 
specific gravity taken at exactly 15.6° in a pycnometer, or by the Westphal 
balance. From the specific gravity the corresponding percentage of 
alcohol by weight or volume,- or the grams per 100 cc. in the distillate, 
is ascertained by reference to the accompanying tables. 

To obtain percentage of alcohol by weight in the sample, multiply 
the per cent by weight in the distillate by the weight of the distillate, and 
divide by the weight of the sample taken; to obtain per cent by volume, 
multiply the per cent by volume in the distillate by 100, and divide by 
the volume of the sample used. 

(2) From the Specific Gravity of the Sample. — In the case of dis- 
tilled liquors having very little residue, an approximation to the true 



ALCOHOLIC BEVERAGES. 



689 



percentage of alcohol may be obtained by using the alcohol table in con- 
nection with the specific gravity of the liquor itself. The accuracy of 
this method depends largely on the freedom from residue, being absolutely 
correct for mixtures of alcohol and water only. 

(3) By Eva poral ion. —Determine the specific gravity of the sample, 
evaporate a measured portion of the liquor (50 or 100 cc.) in a porcelain 




FiG. 112. — Bank of Stills for Alcohol Determination. 

dish over the water-bath to one-fourth its bulk, make up to its original 
volume with distilled water, and determine the specific gravity of this 
second or dealcoholized portion. Add i to the original specific gravity, 
and from this subtract the second specific gravity. The difference is 
the specific gravity corresponding to the alcohol in the liquor, the per 
cent of which is found from the table. 

Example. — Suppose the specific gravity of the original sample to be 
0.9900 while that of the dealcoholized sample is 1.0009. Then 1.9900 — 
1.0009 = 0.9891. .'. Per Cent by volum.e of alcohol = 8.io. 



690 



FOOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL. 
(According to Hehner.) 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 
















1 ' 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Pel 

Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 

Cent 


Grams 


by 


by Vol- 


per 


bv 


by Vol- 


per 


by 


by Vol- 


per 




Weight 


ume. 






Wei>jht 


ume. 


TOO cc. 




Weight 


ume. 


100 cc. 


I .0000 


0.00 


0.00 


0.00 


















0.9999 


0.05 


0.07 


0.05 


0-9959 


2-33 


2-93 


2.32 


0.9919 


4.69 


5-86 


4-65 


8 


O.II 


0.13 


O.II 


8 


2-39 


3 


.00 


2.38 


8 


4-75 


5-94 


4.71 


7 


0.16 


0.20 


0.16 


7 


2-44 


3 


.07 


2.43 


7 


4.81 


6.02 


4-77 


6 


0.21 


0.26 


0.21 


6 


2.50 


3 


-14 


2-49 


6 


4.87 


6.10 


4-83 


5 


0.26 


0-33 


0.26 


5 


2.56 


3 


21 


2-55 


5 


4-94 


6.17 


4.90 


4 


0.32 


0.40 


0.32 


4 


2.61 


3 


28 


2.60 


4 


5.00 


6.24 


4-95 


3 


0-37 


0.46 


0-37 


3 


2.67 


3 


•35 


2.65 


3 


5.06 


6.32 


5.01 


2 


0.42 


0-53 


0.42 


2 


2.72 


3 


42 


2.70 


2 


5-12 


6.40 


5-07 


I 


0.47 


0.60 


0.47 


I 


2.78 


3 


49 


2.76 


I 


5-19 


6.48 


5-14 





0.53 


0.66 


0.53 





2-83 


3 


55 


2.81 





5-25 


6.55 


5.20 


0.9989 


0.58 


0.73 


0.58 


0.9949 


2.89 


3 


62 


2.87 


0.9909 


5-31 


6.63 


5.26 


8 


0.63 


0.79 


0.63 


8 


2.94 


3 


69 


2.92 


8 


5-37 


6.71 


5-32 


7 


0.68 


0.86 


0.68 


7 


3.00 


3 


.76 


2.98 


7 


5-44 


6.78 


5-39 


6 


0.74 


0-93 


0.74 


6 


3.06 


3 


.83 


3-04 


6 


5-50 


6.86 


5-45 


5 


0.79 


0.99 


0.79 


S 


3.12 


3 


90 


3.10 


5 


5-56 


6-94 


5-51 


4 


0.84 


1.06 


0.84 


4 


3.18 


3 


98 


3.16 


4 


5.62 


7.01 


5-57 


3 


0.89 


I-I3 


0.89 


3 


3-24 


4 


05 


3-22 


3 


5-69 


7.09 


5-64 


2 


0-95 


1. 19 


0-95 


2 


3-29 


4 


12 


3-27 


2 


5-75 


7.17 


5-70 


I 


1. 00 


1.26 


1. 00 


I 


3-35 


4 


20 


3-33 


I 


5.81 


7-25 


5-76 





1.06 


1-34 


1.06 





3-41 


4 


27 


3-39 





5-87 


7-32 


5-81 


0.9979 


1. 12 


1.42 


I. 12 


0.9939 


3-47 


4 


34 


3-45 


0.9899 


5-94 


7.40 


5-88 


8 


1. 19 


1-49 


I. 19 


8 


3-53 


4 


42 


3-51 


8 


6.00 


7.48 


5-94 


7 


1.25 


1-57 


I-2S 


7 


3-59 


4 


49 


3-57 


7 


6.07 


7-57 


6.01 


6 


1-31 


1-65 


I-3I 


6 


3-65 


4 


56 


3-^3 


6 


6.14 


7.66 


6.07 


5 


1-37 


1-73 


1-37 


5 


3-71 


4 


63 


3-69 


5 


6.21 


7-74 


6.14 


4 


1-44 


1. 81 


1-44 


4 


3-76 


4 


71 


3-74 


4 


6.28 


7-83 


6.21 


3 


1-50 


1.88 


1-50 


3 


3.82 


4' 


78 


3-80 


3 


6.36 


7.92 


6.29 


2 


1.56 


1.96 


i.s6 


2 


3.88 


4 


85 


3-85 


2 


6.43 


8.01 


6.36 


I 


1.62 


2.04 


1. 61 


I 


3-94 


4 


93 


3-91 


I 


6.50 


8.10 


6.43 





1.69 


2.12 


1.68 





4.00 


5 


00 


3-97 





6.57 


8.18 


6.50 


0.9969 


1-75 


2.20 


1-74 


0.9929 


4.06 


5 


08 


4-03 


0.9889 


6.64 


8.27 


6-57 


8 


1. 81 


2.27 


1.80 


8 


4.12 


5 


16 


4.09 


8 


6.71 


8.36 


6.63 


7 


1.87 


2-35 


1.86 


7 


4.19 


5 


24 


4.16 


7 


6.78 


8-45 


6.70 


6 


1-94 


2-43 


1-93 


6 


4-25 


5 


32 


4.22 


6 


6.86 


8.54 


6.78 


5 


2.00 


2-51 


1-99 


5 


4-31 


5 


39 


4.28 


5 


6-93 


8.63 


6.85 


4 


2.06 


2.58 


2-05 


4 


4-37 


5 


47 


4-34 


4 


7.00 


8.72 


6.92 


3 


2. II 


2.62 


2.10 


3 


4-44 


5 


55 


4.40 


3 


7.07 


8.80 


6-99 


2 


2.17 


2.72 


2.16 


2 


4-50 


5- 


63 


4.46 


2 


7-13 


8.88 


7-05 


I 


2.22 


2.79 


2.21 


I 


4.56 


5- 


71 


4-52 


I 


7 20 


8.96 


7.12 





2.28 


2.86 


2.27 





4.62 


5- 


78 


4-58 





7.27 


9.04 


7.19 



ALCOHOLIC BEVERAGES. 



691 



SPECIFIC GRAVITY AND PERCENTAGE OF A'LCOHO'L— {Continued). 





Absolute Alcohol. _ 


r* . _ . 


Absolute Alcohol. 




Absolute Alcohol. 


Spec. 








Spec. , 


Spec. 


, , 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 


Per 

Cent 


Per 

Cent 


Grama 


by 


by Vol- 


- per 


by 


by Vol- 


per 


15-6° C. 


by 


by Vol- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9879 


7-33 


9-13 


7.24 


0.9829 


10.92 


13-52 


10-73 


0.9779 


14.91 


18.36 


14-58 


8 


7-40 


9.21 


7-31 


8 11.00 


13.62 


10.81 


8 


15.00 


18.48 


14.66 


7 


7-47 


9.29 


7-37 


7 


11.08 


13-71 


10.89 


7 


15-08 


18.58 


14-74 


6 


7-53 


9-37 


7-43 


6 


II. 15 


13.81 


10.95 


6 


15-17 


18.68 


14-83 


5 


7.60 


9-45 


7-50 


5 


11.23 


13.90 11.03 


5 


15-25 


18.78 


14.90 


4 


7.67 


9-54 


7-57 


4 


II. 31 


13.99 II-II 


4 


15-33 


18.88 


14-98 


3 


7-73 


9.62 


7-63 


3 


11.38 


14.09 


II. 18 


3 


15-42 


18.98 


15-07 


2 


7.80 


9-70 


7.70 


2 


11.46 


14.18 


11.26 


2 


15-50 


19.08 


15-14 


I 


7.87 


9-78 


7-77 


I 


11-54 


14.27 


11-33 


I 


15-58 


19.18 


15.21 





7-93 


9.86 


7-83 





11.62 


14-37 


II. 41 





15-67 


19.28 


15-30 


0.9869 


8.00 


9-95 


7.89 


0.9819 


11.69 


14.46 


11.48 


0.9769 


15-75 


19-39 


IS -38 


8 


8.07 


10.03 


7.96 


8 


11.77 


14-56 


11.56 


8 


15-83 


19.49 


15-46 


7 


8.14 


10.12 


8.04 


7 


11.85 


14.65 


11.64 


7 


15-92 


19-59 


15.54 


6 


8.21 


10.21 


8.10 


6 


11.92 


14-74 


11.70 


6 


16.0c 


19.68 


15.62 


5 


8.29 


10.30 


8.17 


5 


12.00 


14.84 


11.78 


5 


16.08 


19-78 


15-70 


4 


8.36 


10.38 


8.24 


4 


12.08 


14-93 


11.85 


4 


16.15 


19.87 


15-76 


3 


8.43 


10.47 


8.31 


3 


12.15 


15.02 


11.92 


3 


16.23 


19.96 


15-84 


2 


8.50 


10.56 


8.38 


2 


12.23 


15.12 


12.00 


2 


16.^1 


20.06 


15-90 


I 


8-57 


10.65 


8.45 


I 


12.31 


15.21 


12.08 


I 


16-38 


20.15 


15-99 


0' 8.64 


10.73 


8.52 





12.38 


15-30 


12.14 





16.46 


20.24 


16.06 


0.9859 8.71 


10.82 


8.s8 


0.9809 


12.46 


15.40 


12.22 


0.9759 


16.54 


20.33 


16.13 


8 8.79 


10.91 


8.66 


8 


12.54 


15-49 


12.30 


8 


16.62 


20.43 


16.21 


7 8.86 


11.00 


8-73 


7 


12.62 


15-58 


12.37 


7 


16.69 


20.52 


16.28 


6 8.93 


11.08 


8.80 


6 


12.69 


15.68 


12.44 


6 


16-77 


20.61 


16.3s 


5 9-00 


II. 17 


8.87 


5 


12.77 


15-77 


12.51 


5 


16.85 


20.71 


16-43 


4 


9.07 


11.26 


8-93 


4 


12.85 


15.86 


12-59 


4 


16.92 


20.80 


16.50 


3 


9.14 


11-35 


9.00 


3 


12.92 


15.96 


12.66 


3 


17 . 00 


20.89 


16.57 


2 


9.21 


11.44 


9.07 


2 


13.00 


16.05 


12.74 


2 


17.08 


20.99 


16.65 


I 


9.29 


11.52 


9.14 


I 


13.08 


16.15 


12.81 


1 


17.17 


21.09 


16.74 





9-36 


II. 61 


9.22 





13-15 


16.24 


12.89 





17-25 


21.19 


16. 8i 


0.9849 


9-43 


11.70 


9.29 


0.9799 


13-23 


16.33 


12.96 


0.9749 


17-33 


21.29 


16.89 


8 


9-50 


1 1 . 79 


9-35 


8 


13-31 


16.43 


13-03 


8 


17.42 


21.39 


16.97 


7 


9-57 


11.87 


9.42 


7 


13-38 16.52 


13.10 


7 


17-50 


21.49 


17.05 


6 


9.64 


11.96 


9-49 


6 


13-46 


16.61 


13.18 


6 


17-58 


21-59 


17--I3 


S 


9.71 


12.05 


9-56 


5 


13-54 


16.70 


13.26 


5 


17.67 


21.69 


17.20 


4 


9-79 


12.13 


9.64 


4 


13.62 


16.80 


^3-33 


4 


17-75 


21.79 


17.29 


3 


9.86 


12.22 


9.71 


3 


13.69 


16.89 


13-40 


3 


17-83 


21.89 


17 37 


2 


9-93 


12.31 


9-77 


2 


13-77 


16.98 


13-48 


2 


17-92 


21.99 


17.46 


I 


10.00 


12.40 


9.84 


I 


13-85 


17.08 


13-56 


I 


18.00 


22.09 


17-54 





10.03 


12.49 


9.92 





13-92 


17.17 


13-63 





18.08 


22.18 


17.61 


0.9839 


10.15 


12.58 


9-99 


0.9789 


14.00 


17.26 


13-71 


0.9739 


18.15 


22.27 


17.68 


8,10.23 


12.68 


10.06 


8 


14.09 


17-37 


13-79 


8 


18.23 


22.36 


17.76 


7,10-31 


12.77 


10.13 


/ 


14.18 


17-48 


13.88 


7 


18.31 


22.46 


17.82 


610.38 


12.87 


10.20 


6 


14.27 


17-59 


13.96 


6 


18.38 


22-55 


17.90 


S 10.46 


12.96 


10.28 


5 


14.36 


17.70 


14.04 


5 


18.46 


22.64 


17-97 


4 10-54 


13-05 


10.36 


4 


14-45 


17.81 


14-13 


4 


18. =^4 


22.73 


18.05 


3 10.62 


13-15 


10.44 


3 


14-55 


17.92 


14-23 


3 


18.62 


22.82 


18.13 


2 10.69 


13-24 


10.51 


2 


14.64 


18.03 


14.32 


2 


18.69 


22.92 


18.19 


1 10.77 


13-34 


10.59 


I 


14-73 


18.14 


14-39 


I 


18.77 


23.01 


18.27 


10.85 

1 


13-43 


10.67 


14.82 

1 


18.25 


14-48 





18.85 


21.10 


18. M 



692 



FOOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/iwwei). 



Spec. 


Absolute Alcohol. 


Spec. 


Absolute Alcohol. 




Absolute Ale 


ohol. 


, 








Spec. 




Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


Grav. 
at 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 


Per 
Cent 


Per 
Cent 


Grama 


by 


by Vol- 


per 


15.6° C. 


by 


by Vol- 


per 


15.6° C. 


by 


by Vol- 


per 




Weight 


ume. 


100 CO, 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 


0.9729 


18.92 


23.19 


18.41 


0.9679 


22.92 


27-95 


22.18 


0.9629 


26.60 


32.27 


25.61 


8 


19.00 


23.18 


18.48 


8 


23.00 


28. 04 


22.26 


8 


26.67 


32-34 


25-67 


7 


19.08 


23-38 


18.56 


7 


23.08 


28.13 


22-33 


7 


26.73 


32.42 


25-73 


6 


19.17 


23.48 


18.65 


6 


23-15 


28.22 


22.40 


6 


26.80 


32-50 


25-79 


5 


19-25 


23-58 


18.73 


5 


23-23 


28. 31 


22.47 


5 


26.87 


32-58 


25-85 


4 


19-33 


23.68 


18.80 


4 


23-31 


28.41 


22.54 


4 


26.93 


32-65 


25-91 


3 


19.42 


23-78 


18.88 


3 


23.38I 28.50 


22.61 


3 


27.00 


32-73 


25-98 


2 


19-5C 


23.88 


18.9s 


2 


23.46 


28.59 


22.69 


2 


27-07 


32.81 


26.04 


I 


19-58 


23.98 


19-03 


I 


23-54 


28.68 


22.76 


I 


27.14 


32-90 


26.10 





19.67 


24.08 


19.12 





23.62 


28.77 


22.83 





27-21 


32.98 


26.17 


0.9719 


19-75 


24.18 


19.19 


0.9669 


23.69 


28.86 


22.90 


0.9619 


27.29 


33-06 


26.25 


8 


19.83 


24.28 


19.27 


8 


23-77 


28.95 


22-97 


8 


27.36 


33-15 


26.31 


7 


19.92 


24.38 


19.36 


7 


23-85 


29.04 


23-05 


7 


27-43 


33-23 


26.37 


6 


20.00 


24.48 


19-44 


6 


23-92 


29-13 


23.11 


6 


27-50 


33-3^ 


26.43 


5 20.08 


24-58 


19-51 


5 


24.00 


29.22 


23-19 


5 


27-57 


33-39 


26.51 


4 20.17 


24.68 


19-59 


4 


24.08 


29-31 


23-27 


4 


27.64 


33-48 


26.57 


3 


20.25 


24-78 


19.66 


3 


24-15 


29.40 


23-33 


3 


27.71 


33-56 


26.64 


2 


20.33 


24.88 


19-74 


2 


24-23 


29.49 


23-40 


2 


27-79 


33-64 


26.71 


I 


20.42 


24.98 


19.83 


I 


24-31 


29-58 


23-48 


I 


27.86 


33-73 


26.78 





20.50 


25-07 


19.90 





24-38 


29.67 


23-55 





27-93 


33.81 


26.84 


0.9709 


20.58 


25-17 


19.98 


0.9659 


24.46 


29.76 


23.62 


0.9609 


28.00 


33-89 


26.90 


8 20.67 


25-27 


20.07 


8 


24-54 


29.86 


23.70 


8 


28.06 


33-97 


26.96 


7 


20.75 


25-37 


20.14 


7 


24.62 


29-95 


23-77 


7 


28.12 


34-04 


27.01 


6 


20.83 


25-47 


20.22 


6 


24-69 


30.04 


23.84 


6 


28.19 


34-11 


27.07 


5 


20.92 


25-57 


20.30 


5 


24-77 


30-13 


23-91 


5 


28.25 


34-18 


27-13 


4 


21.00 


25-67 


20.33 


4 


24-85 


30.22 


23-99 


4 


28.31 


34-25 


27.18 


3 


21.08 


25-76 


20.46 


3 


24.92 


30-31 


24-05 


3 


28.37 


34-33 


27.24 


2 


21.15 


25.86 


20.52 


2 


25.00 


30.40 


24.12 


2 


28.44 


34-40 


27-31 


I 


21.23 


25-95 


20.59 


1 


25-07 


30.48 


24.19 


I 


28.50 


34-47 


27.36 





21.31 


26.04 


20.67 





25.14 


30.57 


24.26 





28.56 


34-54 


27.42 


0.9699 


21.38 


26.13 


20.73 


0.9649 


25.21 


30.65 


24-32 


0-9599 


28.62 


34-61 


27-47 


8 


21.46 


26.22 


20.81 


8 


25.29 


30-73 


24-39 


8 


28.69 


34-69 


27-53 


7 


21.54 


26.31 


20.89 


7 


25-36 


30-82 


24-46 


7 


28.75 


34-76 


27-59 


■ 6 


21.62 


26.40 


20.96 


6 


25-43 


30.90 


24-53 


6 


28.81 


34-83 


27-64 


5 


21.69 


26.49 


21.03 


5 


25-50 


30.98 


24-59 


5 


28.87 


34-90 


27.70 


4 


21.77 


26.58 


21. II 


4 


25-57 


31-07 


24.66 


4 


28.94 


34-97 


27-76 


3 


21.85 


26.67 


21.18 


3 


25-64 


S'^-^S 


24.72 


3 


29.00 


35-05 


27.82 


2 


21.92 


26.77 


21.25 


2 


25-71 


31-23 


24.79 


2 


29-07 


35-12 


27.89 


1 


22.00 


26.86 


21-33 


I 


25-79 


31-32 


24-86 


1 


29-13 


35-20 


27-95 





22.08 


26.95 


21.40 





25.86 


31-40 


24-93 





29.20 


35-28 


28.00 


0.9689 


22.15 


27.04 


21.47 


0.9639 


25-93 


31-48 


24-99 


0.9589 


29.27 


35-35 


28.07 


8 


22.23 


27-13 


21-54 


8 


26.00 


31-57 


25.06 


8 


29-33 


35-43 


28.12 


7 


22.31 


27.22 


21.61 


7 


26.07 


31-65 


25.12 


7 


29.40 


35-51 


28.18 


6 


22.38 


27-31 


21.68 


6 


26.13 


31.72 


25.18 


6 


29-47 


35-58 


28.24 


5 


22.46 


27.40 


21 .76 


5 


26.20 


31.80 


25-23 


5 


29-53 


35-66 


28.30 


4 


22.54 


27-49 


21.83 


4 


26.27 


31.88 


25-30 


4 


29.60 


35-74 


28.36 


3 


22.62 


27-59 


21.90 


3 


26-33 


31.96 


25-36 


3 


29.67 


35-81 


28. 4i 


2 


22.69 


27.68 


21.96 


2 


26.40 


32-03 


25-43 


2 


29-73 


35-89 


28. 4? 


I 


22.77 


27.77 


22.01 


I 


26.47 


32.11 


25-49 


I 


29.80 


35-97 


28.54 





22.85 


27.86 


22.12 





26.53 


32.19 


25-55 


c 


29.87 


36.04 


28.61 



ALCOHOLIC BEVERAGES. 



693 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOKO'L— (Continued). 





Absc 


lute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 




Spec. 






















Grav. 
at 


Per 


Per 


Grams 


Grav. 

at 


Per 


Per 


Grams 


Grav. 
at 


Per 


Per 


Grams 


15.6° c. 


Cent 
by 


Cent 
by Vol- 


per 
100 cc. 


15.6° C. 


Cent 
by 


Cent 
by Vol- 


per 

100 CC. 


15.6° C. 


Cent 
by 


Cent 

by Vol- 


per 

100 CC. 




Weight 


ume. 






Weight 


ume. 






Weight 


ume. 




0.9579 


29-93 


36.12 


28.67 


0-9529 


32-94 


39-54 


31-38 


0.9479 


35-55 


42-45 


33-70 


8 


30.00 


36.20 


28.73 


8 


33-00 


39.61 


31-43 


8 


35-60 


42.51 


33-75 


7 


30.06 


36.26 


28.78 


7 


33-06 


39.68 


31-48 


7 


35-65 


42.56 


33-79 


6 


30.11 


36.32 


28.82 


6 


33-12 


39-74 


31-53 


6 


35-70 


42.62 


33-83 


5 


30-17 


36-39 


28.88 


5 


33-18 


39.81 


31-59 


5 


35-75 


42.67 


33-88 


4 


30.22 


36-45 


28.92 


4 


33-24 


39-87 


31-63 


4 


35-80 


42-73 


33-92 


3 


30.28 


36-51 


28.98 


3 


33-29 


39-94 


31.69 


3 


35-85 


42-78 


33-97 


2 


30-33 


36-57 


29.03 


2 


33-35 


40.01 


31-74 


2 


35-90 


42.84 


34-01 


I 


30-39 


36.64 


29.08 


1 


33-41 


40.07 


31.80 


I 


35-95 


42-89 


34-05 





30.44 


36.70 


29.13 





33-47 


40.14 


31.86 





36-00 


42-95 


34-09 


0.9569 


30-50 


36.76 


29.18 


0.9519 


33-53 


40.20 


31-91 


0.9469 


36.06 


43-01 


34-14 


8 


30-56 


36-83 


29-23 


8 


33-59 


40.27 


31.96 


8 


36.11 


43-07 


34-09 


7 


30.61 


36.89 


29-27 


7 


33-65 


40.34 


32-01 


7 


36-17 


43-13 


34-24 


6 


30.67 


36-95 


29-33 


6 


33-71 


40.40 


32-07 


6 


36-22 


43-19 


34.28 


5 


30-72 


37.02 


29.38 


5 


33-76 


40.47 


32.12 


5 


36.28 


43-26 


34-34 


4 


30.78 


37.08 


29-43 


4 


33-82 


40-53 


32-17 


4 


36-33 


43-32 


34-38 


3 


30.83 


37.14 


29.48 


3 


33-88 


40.60 


32.22 


3 


36-39 


43-38 


34-44 


2 


30.89 


37.20 


29-53 


2 


33-94 


40.67 


32-27 


2 


36.44 


43-44 


34-48 


I 


30.94 


37-27 


29-58 


I 


34.00 


40.74 


32-32 


I 


36.50 


43-50 


34-54 





31.00 


37-34 


29.63 





34-05 


40.79 


32-37 





36.56 


43-56 


34-58 


0.9559 


31.06 


37.41 


29.69 


0.9509 


34-10 


.40.84 


32.41 


0.9459 


36.61 


43-63 


34-63 


8 


31.12 


37-48 


29-74 


8 


34-14 


40.90 


32-45 


8 


36.67 


43-69 


34-69 


7 


31-19 


37-55 


29.81 


7 


34-19 


40-95 


32-49 


7 


36.72 


43-75 


34-73 


6 


31-25 


37.62 


29.86 


6 


34-24 


41.00 


32-54 


6 


36-78 


43-81 


34-79 


5 


3^-3^ 


37-69 


29.91 


5 


34-29 


41-05 


32-59 


5 


36-83 


43-87 


34-83 


4 


31-37 


37-76 


29.97 


4 


34-33 


41. II 


32.63 


4 


36.89 


43-93 


34.88 


3 


31.44 


37-83 


30-03 


3 


34.38 


41.16 


32.67 


3 


36.94 


44.00 


34-92 


2 


31-50 


37-90 


30.09 


2 


34.43 


41.21 


32-71 


2 


37-00 


44.06 


34-96 


I 


31-56 


37-97 


30.14 


I 


34.48 


41.26 


32-75 


I 


37-06 


44.12 


35-02 





31.62 


38.04 


30.20 





34-52 


41-32 


32-79 





37-" 


44.18 


35-07 


0.9349 


31.69 


38.11 


30.26 


0.9499 


34-57 


41-37 


3^-ft 


0.9449 


37-17 


44-24 


35-12 


8 


31-75 


38.18 


30-31 


8 


34.62 


41.42 


32.88 


8 


37-22 


44-30 


35-10 


7 


31.81 


38-25 


30-36 


7 


34-67 


41-48 


32-92 


7 


37-28 


44-36 


35-21 


6 


31-87 


38-33 


30.42 


6 


34-71 


41-53 


32-96 


t 


37-33 


44-43 


35 -2<' 


5 


31-94 


38.40 


30-48 


5 


34-76 


41-58 


33-00 


5 


37-39 


44-49 


35-31 


4 


32.00 


38.47 


30-53 


4 


34-81 


41.63 


33-04 


4 


37-44 


44-55 


35-35 


3 


32.06 


38-53 


30-59 


3 


34.86 


41.69 


33-09 


3 


37-50 


44.61 


35-41 


2 


32.12 


38.60 


30.64 


2 


34-90 


41.74 


33-'^3 


2 


37-56 


44.67 


35-46 


I 


32.19 


38.68 


30-71 


I 


34-95 


41.79 


33-17 


I 


37.61 


44-73 


35-51 





32-25 


38.75 


30-77 





35-00 


41.84 


33-21 


c 


37-67 


44-79 


35-56 


C.9S39 


32-31 


38.82 


30.81 


0.9489 


35-05 


41.90 


32.26 


0.9439 


37-73 


44-86 


35-60 


8 


32-37 


38.89 


30.87 


8 


35-10 


41.95 


33-30 


8 


37-78 


44-92 


35-65 


7 


32-44 


38.96 


30.93 


7 


35-15 


42.01 


33-34 


7 


37-83 


44-98 


35-70 


6 


32-50 


39-04 


30-99 


6 


35-20 


42.06 


33-39 


6 


37-89 


45-04 


35-75 


5 


32-56 


39-11 


31-05 


5 


35-25 


42.12 


33-43 


5 


37-49 


45-10 


35-80 


4 


32.62 


39.18 


31.10 


4 


35-30 


42.17 


33-48 


4 


38.00 


45.16 


35-85 


3 


32.69 


39-25 


31-15 


3 


35-35 


42.23 


33-53 


3 


38-06 


45-22 


35-90 


2 


32-75 


39-32 


31.20 


2 


35-40 


42.29 


33-57 


2 


38.11 


45.28 


35-95 


1 


32.81 


39-40 


31.26 


I 


35-45 


42.34 


33-61 


I 


38-17 


45»34 


36-00 





32.87 


39-47 


31-32 





35-50 


42.40 


33-65 





38.22 


45-41 


36.04 



694 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF A-LCOKOL— (Continued). 





Absolute Alcohol. 


Spec. 


Absc 


lute Alcohol. 




Absolute Alcohol. 


Spec. 












Spec. 








Grav. 

at 


Per 
Cent 


Per 

Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 

Cent 


Per 
Cent 


Grams 


Grav. 

at 
15.6° C. 


Per 
Cent 


Per 
Cent 


Grams 


15.6° C. 


by 


by Vol- 


per 


by 


by Vol- 


per 


by 


by Vel- 


per 




Weight 


ume. 


100 cc. 




Weight 


ume. 


100 cc. 




Weight 


um e._ 


100 cc. 


0.9429 


38.28 


45-47 


36-08 


0-9379 


40-85 


48.26 38.31 


0.9329 


43-29 


50-87 


40.38 


8 


38-33 


45-53 


36-13 


8 


40.90 


48.32 38.35 


8, 43-33 


50.92 


40.42 


7 


38.39 


45-59 


36-18 


7 


40.95 


48..37' 38.39 


7! 43-39 


50-97 


40.46 


6 


38-44 


45-65 


36-23 


6 


41.00 


48-43 38.44 


6 43 43 


51.02 


40.50 


5 


38.50 


45-71 


36.28 


5 


41-05 


48.48 38.48 


5 


43-48 


51-07 


40.54 


4 


38.56 


45-77 


36-33 


4 


41.10 


48-54 38-52 


4 


43-52 


51.12 


40.58 


3 


38.61 


45-83 


36.38 


3 


41-15 


48.59 38-58 


3 


43-57 


51-17 


40.62 


2 


38.67 


45-89 


36-43 


2 


41.20 


48.64 38.62 


2 


43-62 


51.22 


40.66 


I 


38.72 


45-95 


36.48 


I 


41-25 


48.70 38.66 


I 


43-67 


51-27 


40.70 





38.78 


46.02 


36.53 





41-30 


48-75 


38.70 





43-71 


51-32 


40.74 


0.9419 


38.83 


46.08 


36.57 


0.9369 


41.35 


48.80 


38.74 


0.9319 43.76 


51-38 


40.78 


8 


38.89 


46.14 


36. 62 


8 


41.40 


48.86 38.78 


8 43.81 


51-43 


40.81 


7 


38-94 


46.20 


36-67 


7 


41.45 


48.91 ^8.82 


7 43.86 


51.48 


40.85 


6 


39.00 


46.26 


36.72 


6 


41.50 


48.97; 38.87 


6| 43-90 


51-53 


40.89 


5 


39-05 


46.32 


36-76 


5 


41-55 


49-02^ 38.91 


5 


43-95 


51-58 


40.93 


4 


39.10 


46-37 


36.80 


4 


41.60 


49.07, 38.95 


4 


44.00 


51-63 


40.97 


3 


39.15 


46.42 


36-85 


3 


41-65 


49.13 38-99 


3 


44-05 


51.68 


41.01 


2 


39.20 


46.48 


36.89 


2 


41.70 


49.18 


39-04 


2 


44-09 


51-72 


41.05 


1 


39-25 


46.53 


36-94 


I 


41-75 


49-23 


39.08 


I 


44.14 


51-77 


41.09 





39-30 


46.59 


36.98 





41.80 


49.29 


39-13 





44.18 


51.82 


41 13 


9409 


39-35 


46.64 


37.02 


0.9359 


41.85 


49-34 


39-17 


0.9309 


44-23 


51-87 


41.17 


8 


39-40 


46.70 


37-07 


8 


41.90 


49 40 


39.21 


8 


44-27 


5I-9J 


41-20 


7 


39.45 


46.75 


37-11 


7 


41-95 


49-45 


39-25 


7 


44-32 


51.96 


41.24 


6 


39-50 


46.80 


37-15 


6 


42.00 


49 50 


39-30 


6 


44-36 


52.01 


41.28 


5 


39-55 


46.86 


37-19 


5 


42-05 


49-55 


39-34 


5 


44.41 


52.06 


41-31 


4 


39.60 


46.91 


37-23 


4 


42.10 


49.61 


39-38 


4 


44-46 


52.10 


41-35 


3 


39-65 


46.97 


.37-27 


3 


42.14 


49.66 


39-42 


3 


44-50 


52-15 


41.49 


2 


39-70 


47.02 


37-32 


2 


42-19 


49-71 


39-46 


2 


44.55 


52-20 


41.43 


I 


39-75 


47.08 


37-36 


I 


42.24 


49-76 


39-50 


I 


44-59 


52-25 


41.47 





39.80 


47-13 


37-41 





42.29 


49.81 


39-54 





•44.64 


52-29 


41.51 


0.9399 


39-85 


47.18 


37-45 


0.9349 


42.33 


49.86 


39-58 


0.9290 


44.68 


52-34 


41.55 


8 


39-90 


47-24 


37-49 


8 


42.38 


49-91 


39-62 


8 


44-73 


52-39 


41.59 


7 


39-95 


47.29 


37-53 


7 


42.43 


49-96 


39.66 


7 


44.77 


52-44 


41.63 


6 


40.00 


47-35 


37-58 


6 


42.48 


50.01 


39-70 


6 


44.82 


52.48 


41.67 


5 


40.05 


47.40 


37.62 


5 


42.52 


50-06 


39.74 


5 


44.86 


52-53 


41.70 


4 


40.10 


47-45 


37-67 


4 


42-57 


50.11 


39-78 


4 


44.91 


52-58 


41-74 


3 


40.15 


47-51 


37-71 


3 


42.62 


50.16 


39.82 


3 


44.96 


52-63 


41-77 


2 


40.20 


47-56 


37-75 


2 


42.67 


50.21 


39-86 


2 


45.00 


52. 68 


41.81 


I 


40.25 


47.62 


37.80 


I 


42.71 


50.26 


39-90 


I 


45-05 


52.72 


41-85 





40.30 


47-67 


37-84 





42.76 


50.31 


39-94 





45-09 


52-77 


41.89 


0.9380 


40.35 


47.72 


37-88 


0-9339 


42.81 


50.37 


39.98 


0.9289 


45-14 


52-82 


41-93 


8 


40.40 


47.78 


37-92 


8 


42.86 


50.42 


40.02 


8 


45-18 


52.87 


41.97 


7 


40.45 


47-83 


37-96 


7 


42.90 


50-47 


40.06 


7 


45-23 


52.91 


42.00 


6 


40-50 


47.89 


38.00 


6 


42.95 


50-52 


40.10 


6 


45-27 


52-96 


42.04 


5 


40.55 


47-94 


38-05 


5 


43.00 


50-57 


40.14 


5 


45-32 


53-01 


42.08 


4 


40.60 


47-99 


38.09 


4 


43-05 


50.62 


40. 18 


4 


45-36 


53-06 


42.12 


3 


40.65 


48.05 


38.13 


3 


43.10 


50.67 


40.22 


3 


45-41 


53-10 


42.16 


2 


40.70 


48.10 


38-18 


2 


43-13 


50.72 


40.26 


2 


45-46 


53-15 


42.19 


I 


40.75 


48.16 


38.22 


I 


43-19 


50.77 


40.30 


I 


45-50 


S3-20 


42.23 





40.80 


48.21 


38.27 





43-24 


50.82 


40.34 





45-55 


53-24 


42.27 



ALCOHOLIC BEVERAGES. 



695 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (Con/inwcd). 





Absolute Alcohol. 


c^.. 


Absolute Alcohol. 




Absolute Alcohol. 


Spec. - 
Grav. 


Per 


Per 


bpec. 
Grav. 

at 
15.6° C. 


Per 


Per 


Grav. 

at 


Per 


Per 


at 


Cent 


Cent 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


IS. 6" C. 


by 


by Vol- 


by 


by Vol- 




by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.9279 


45-59 


53-29 


0.9229 


47-86 


55-65 


0.9179 1 


50-13 


57-97 


8 


45-64 


53-34 


8 


47.91 


55-69 


8 


50-17 


58.01 


7 


45.68 


53-39 


7 


47.96 


55-74 


7 


50.22 


58.06 


6 


45-73 


53-43 


6 


48.00 


55-79 


6 


50-26 


58.10 


5 


45-77 


53-48 


5 


48.05 


55-83 


5 


50-30 


58-14 


4 


45.82 


53-53 


4 


48.09 


55-88 


4 


50-35 


58.19 


3 


45.86 


53-58 


3 


48.14 


55-93 


3 


50-39 


58-23 


2 


45-91 


53-62 


2 


48.18 


55-97 


2 


50-43 


58.28 


I 


45-96 


53-67 


I 


48.23 


56.02 


I 


50-48 


58.32 





46.00 


53-72 





48.27 


56-07 





50.52 


5S-36 


0.9269 


46.05 


53-77 


0.9219 


48.32 


56.11 


0.9169 


50-57 


58-41 


8 


46.09 


53-81 


8 


48.36 


56.16 


8 


50.61 


58-45 


7 


46.14 


53-86 


7 


48.41 


56.21 


7 


50-65 


58-50 


6 


46.18 


53-91 


6 


48.46 


56.25 


6 


50.70 


58-54 


5 


46.23 


53-yS 


5 


48.50 


56-30 


S 


50-74 


58-58 


4 


46.27 


54-00 


4 


48.55 


56-35 


4 


50-78 


58-63 


3 


46.32 


54-05 


3 


48-59 


56-40 


3 


50-S3 


58.67 


2 


46.36 


54.10 


2 


48.64 


56-44 


2 


50-87 


58-72 


1 


46.41 


54-14 


I 


48.68 


56-49 


I 


50.91 


58-76 





46.46 


54-19 





48.73 


56-54 





50.96 


58-80 


«-9259 


46.50 


54-24 


0.9200 


48.77 


56-58 


0.9159 


51.00 


58-85 


8 


46.55 


54-29 


8 


48.82 


56-63 


8 


51.04 


58.89 


7 


46.59 


54-33 


7 


48.86 


56.68 


7 


51.08 


58-93 


6 


46.64 


54-38 


6 


48.91 


56.72 


6 


51-13 


58-97 


5 


46.68 


54-43 


5 


48. 96 


56.77 


5 


51-17 


59-01 


4 


46.73 


54-47 


4 


49.00 


56-82 


4 


51.21 


59-05 


3 


46.77 


54-52 


3 


49-04 


56.86 


3 


51-25 


59.09 


2 


46.82 


54-57 


2 


49.08 


56.90 


2 


51-29 


59-14 


I 


46.86 


54-62 


I 


49.12 


56-94 


I 


51-33 


59-18 





46.91 


54.66 





49.16 


56.98 





51-38 


59.22 


0.9249 


46.96 


54-71 


0.9199 


49-20 


57-02 


1 0.9149 


51-42 


59.26 


8 


47.00 


54-76 


Proof 8 


49-24 


57-06 


8 


51.46 


59-30 


7 


47-05 


54.80 


7 


49-29 


57-10 


7 


51-50 


59-34 


6 


47-09 


54-85 


6 


49-34 


57-15 


6 


51-54 


59-39 


5 


47-14 


54-90 


S 


49-39 


57.20 


5 


51-58 


59-43 


4 


47-18 


54-95 


4 


49-44 


57-25 


4 


51-63 


59-47 


3 


47-23 


54-99 


3 


49-49 


57-30 


3 


51-67 


59-51 


2 


47.27 


55-04 


2 


49-54 


57-35 


2 


51-71 


59-55 


I 


47-32 


55-09 


I 


49-59 


57.40 


I 


51-75 


59-59 





47-36 


55-13 





49-64 


57-45 





51-79 


59-63 


0.9239 


47-41 


55-18 


0.9189 


49-68 


57-49 


0.9139 


SI -83 


59.68 


8 


47-46 


55-23 


8 


49-73 


57-54 


8 


51.88 


59-72 


7 


47-50 


55-27 


7 


49-77 


57-59 


7 


51.92 


59-76 


6 


47-55 


55-32 


6 


49.82 


57-64 


6 


51.96 


59.80 


5 


47-50 


55-37 


5 


49.86 


57-69 


5 


52.00 


59.84 


4 


47.64 


55-41 


4 


49-91 


57-74 


4 


52-05 


59.89 


3 


47-68 


55-46 


3 


49-95 


.57-79 


3 


52.09 


59-93 


2 


47-73 


55-51 


2 


50.00 


57-84 


2 


52.14 


59.98 


I 


47-77 


55-55 


I 


50.04 


57-88 


I 


52. iS 


60.02 





47-82 


55-60 





50.09 


58.92 





52-23 


60.07 



696 



FOOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOHOL— (CoM/m«e(f). 



Spec. 
Grav. 

at 
15.6° C. 


Absolute 


Alcohol. 


Spec. 
Grav. 

at 
15-6° C. 


Absolute Alcohol. 




Absolute AlcohoL 


Per 
Cent 
by 


Per 

Cent 
by Vol- 


Per 

Cent 
by 


Per 

Cent 

by Vol- 


Spec. 
Grav. 

at 
15.6° C. 


Per 

Cent 
by 


Per 

Cent 

by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.9*129 


52.27 


60.12 


0.9079 


54-52 


62.36 


0.9029 


56.82 


64.63 


8 


52-32 


60.16 


8 


54-57 


62.41 


8 


56.86 


64.67 


7 


52.36 


60.21 


7 


54.62 


62.45 


7 


56.91 


64.71 


6 


52-41 


60.25 


6 


54-67 


62.50 


6 


56.95 


64.76 


S 


52-45 


60.30 


5 


54-71 


62.55 


5 


57.00 


64.80 


4 


52-50 


60.34 


4 


54-76 


62.60 


4 


57-04 


64-85 


3 


52-55 


60.39 


3 


54-81 


62.65 


3 


57-08 


64.89 


2 


52-59 


60.44 


2 


54.86 


62.69 


2 


57-13 


64-93 


1 


52-64 


60.47 


I 


54-90 


62.74 


I 


57-17 


64.97 





52-68 


60.52 





54-95 


62.79 





57-21 


65.01 


0.9119 


52-73 


60.56 


0.9069 


55-00 


62.84 


0.9019 


57-25 


65-05 


8 


52-77 


60.61 


8 


55-05 


62.88 


8 


57-29 


65-09 


7 


52.82 


60.65 


7 


55-09 


62.93 


7 


57-33 


65-13 


6 


52-86 


60.70 


6 


55-14 


62.97 


6 


57-38 


65-17 


5 


52-91 


60.74 


5 


55-18 


63.02 


5 


57-42 


65.21 


4 


52-95 


60.79 


4 


55-23 


63-06 


4 


57-46 


65-25 


3 


53-00 


60.85 


3 


55-27 


63.11 


3 


57-50 


65.29 


2 


53-04 


60.89 


2 


55-32 


63-15 


2 


57-54 


65-33 


I 


53-09 


60.93 


I 


55-36 


63.20 


I 


57-58 


65.37 





53-13 


60.97 





55-41 


63-24 





57-63 


65.41 


0.9109 


53-17 


61.02 


0.9059 


55-45 


63.28 


0.9009 


57-67 


65-45 


8 


53-22 


61.06 


8 


55-50 


63-33 


8 


57-71 


65-49 


7 


53-26 


61.10 


7 


55-55 


63-37 


7 


57-75 


65-53 


6 


53-30 


61.15 


6 


55-59 


63-42 


6 


57-79 


65-57 


5 


53-35 


61.19 


5 


55-64 


63-46 


5 


57-83 


65-61 


4 


53-39 


61.23 


4 


55-68 


63-51 


4 


57-88 


65-65 


3 


53-43 


61.28 


3 


55-73 


63-55 


3 


57-92 


65-69 


2 


53-48 


61.32 


2 


55-77 


63.60 


2 


57-96 


65-73 


I 


53-52 


61-36 


I 


55-82 


63.64 


I 


c;8.oo 


65-77 





53-57 


61.40 





55-86 


63-69 





58-05 


65.81 


0.9099 


53-61 


61.45 


0.9049 


55-91 


63-73 


0.8999 


58-09 


65-85 


8 


53-65 


61.49 


8 


55-95 


63-78 


8 


58.14 


65.90 


. 7 


53-70 


61-53 


7 


56.00 


63.82 


7 


58.18 


65-94 


6 


53-74 


61-58 


6 


56.05 


63-87 


6 


58-23 


65 .99 


5 


53-78 


61.62 


5 


56.09 


63.91 


5 


58.27 


66.03 


4 


53-83 


61.66 


4 


56.14 


63-96 


4 


58.32 


66.07 


3 


53-87 


61.71 


3 


56.18 


64.00 


3 


58.36 


66.12 


2 


53-91 


61-75 


2 


56.23 


64.05 


2 


58.41 


66.16 


I 


53-96 


61.79 


I 


56.27 


64.09 


I 


58-45 


66.21 





54.00 


61.84 





56-32 


64.14 





58-50 


66.25 


0.9089 


54-05 


61.88 


0.9039 


56.36 


64.18 


0.8989 


58-55 


66.29 


8 


54-10 


61-93 


8 


56.41 


64.22 


8 


58-59 


66.34 


7 


54.14 


61.98 


7 


56-45 


64.27 


7 


58.64 


66.38 


6 


54-19 


62.03 


6 


56-30 


64.31 


6 


S8.68 


66.43 


5 


54-24 


62.07 


5 


56.55 


64-36 


5 


58.73 


66.47 


4 


54 - 29 


62.12 


4 


56.59 


64.40 


4 


58.77 


66.51 


3 


54-33 


62.17 


3 


56.64 


64-45 


3 


58.82 


66. s6 


2 


54-38 


62.22 


2 


56.68 


64-49 


2 


58.86 


66.60 


I 


54-43 


62.26 


I 


56-73 


64-54 


I 


58.91 


66.65 





54-48 


62.31 





56-77 


64.58 





58.95 


66.69 



ALCOHOLIC BEVERAGES. 



697 



SPECIFIC GRAVITY AND PERCENTAGE OF ALCOUO'L— (.Continued). 



Spec. 

Grar. 

at 


Absolute Alcohol. 


Spec. 

Grav. 

at 


Absolute 


Alcohol. 


Spec. 
Grav. 

at 


Absolute 


Alcohol. 


Per 


Per 


Per 


Per 


Per 


Per 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 




by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8979 


59.00 


66.74 


0.8929 


61.13 


68.76 


0.8879 


63-30 


70.81 


8 


59-04 


66.78 


8 


61.17 


68 


.80 


8 


63-35 


70.85 


7 


59-09 


66.82 


7 


61.21 


68 


-83 


7 


63-39 


70.89 


6 


59-13 


66.86 


6 


61.25 


68 


87 


6 


63-43 


7o»93 


5 


59-17 


66.90 


5 


61.29 


68 


91 


5 


63-48 


70.97 


4 


59.22 


66.94 


4 


61-33 


68 


95 


4 


63-52 


71.01 


3 


59.26 


66.99 


3 


61.38 


68 


99 


3 


63-57 


71-05 


2 


59-30 


67.03 


2 


61.42 


69 


03 


2 


63.61 


71.09 


I 


59-35 


67.07 


I 


61.46 


69 


07 


I 


63-65 


71-13 





59-39 


67.11 





61.50 


69 


II 





63.70 


71.17 


0.8969 


59-43 


67-15 


0.8919 


61.54 


69 


15 


0.8869 


63-74 


71.22 


8 


59-48 


6>.i9 


8 


61.58 


69 


19 


8 


63-78 


71.26 


7 


59-52 


67.24 


7 


61.63 


69 


22 


7 


63-83 


71-30 


6 


59-57 


67.28 


6 


61.67 


69 


26 


6 


63.87 


71-34 


5 


59-61 


67.32 


5 


61.71 


69 


30 


5 


63.91 


71-38 


4 


59-65 


67-36 


4 


61-75 


69 


34 


4 


63-96 


71.42 


3 


59-70 


67.40 


3 


61.79 


69 


38 


3 


64.00 


71.46 


2 


59-74 


67.44 


2 


61.83 


69 


42 


2 


64.04 


71-50 


I 


59-78 


.67.49 


I 


61.88 


69 


46 


I 


64.09 


71-54 





59-83 


67-53 





61.92 


69 


50 





64.13 


71-58 


0.8959 


59-87 


67-57 


0.8909 


61.96 


69 


54 


0.8859 


64.17 


71.62 


8 


59-91 


67.61 


8 


62.00 


69 


58 


8 


64.22 


71.66 


7 


59-96 


67.65 


7 


62.05 


69 


62 


7 


64.26 


71.70 


6 


60.00 


67.69 


6 


62.09 


69 


66 


6 


64.30 


71-74 


5 


60.04 


67-73 


5 


62.14 


69 


71 


5 


64-35 


71.78 


4 


60.08 


67.77 


4 


62.18 


69 


75 


4 


64-39 


71.82 


3 


60.13 


67.81 


3 


62.23 


69 


79 


3 


64-43 


71.86 


2 


60.17 


67.85 


2 


62.27 


69 


84 


2 


64.48 


71.90 


I 


60.21 


67.89 


I 


62.32 


69 


88 


I 


64.52 


71-94 





60.26 


67-93 





62.36 


69 


92 





64-57 


71.98 


0.8940 


60.29 


67.97 


0.8899 


62.41 


69 


96 


0.8849 


64.61 


72.02 


8 


60.33 


68.01 


8 


62.45 


70 


01 


8 


64.65 


72.06 


7 


60.38 


68.05 


7 


62.50 


70 


05 


7 


64-70 


72.10 


6 


60.42 


68.09 


1 6 


62.55 


70 


09 


6 


64.74 


72.14 


5 


60.46 


68.13 


5 


62.59 


70 


14 


5 


64.78 


72.18 


4 


60.50 


68.17 


4 


62.64 


70 


18 


4 


64.83 


72.22 


3 


60.54 


68.21 


3 


62.68 


70 


22 


3 


64.87 


72.26 


2 


60.58 


68.25 


2 


62.73 


70 


27 


2 


64.91 


72.30 


I 


60.63 


68 29 


I 


62.77 


70 


31 


I 


64.96 


72-34 





60.67 


68.33 





62.82 


70 


35 





65.00 


72.38 


0.8939 


60.71 


68.36 


0.8889 


62.86 


70 


40 


0.8839 


65.04 


72.42 


8 


60.76 


68.40 


8 


62.91 


70 


44 


8 


65.08 


72.46 


7 


60.79 


68.44 


7 


62.95 


70 


48 


7 


65-13 


72.50 


6 


60.83 


68.48 


6 


63.00 


70 


52 


6 


65-17 


72-54 


5 


60.88 


68.52 


5 


63.04 


70 


57 


5 


65.21 


72.58 


4 


60.92 


68.56 


4 


63-09 


70 


61 


4 


65-25 


72.61 


3 


60.96 


68.60 


3 


63-13 


70 


65 


3 


65.29 


72.65 


2 


61.00 


68.64 


2 


63-17 


70 


69 


2 


65-33 


72.69 


I 


61.04 


68.68 


I 


63.22 


70 


73 


I 


65-38 


72-73 





61.08 


68.72 





63.26 


70. 


77 





65-42 


72.77 



698 



FOOD INSPECTION AND ANALYSIS. 



SPECIFIC GRAVITY AND PERCENTAGE OF Al.COUO'L— (Continued). 





Absolute Alcohol. 




Absolute Alcohol. 


Spec. 


Absolute Alcohol. 


Spec. 






Spec. 










Grav. 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


at 
15.6° C. 


Cent 


Cent 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


•ume. 




Weight. 


ume. 


0.8829 


65.46 


72.80 


0.8779 


67-58 


74-74 


0.8729 


69.67 


76.61 


8 


65-50 


72.84 


8 


67.63 


74-78 


8 


69.71 


76-65 


7 


65-54 


72.88 


7 


67.67 


74.82 


7 


69-75 


76.68 


6 


65-58 


72.92 


6 


67.71 


74.86 


6 


69.79 


76.72 


5 


65-63 


72.96 


5 


67-75 


74.89 


5 


69.83 


76.76 


4 


65-67 


72.99 


4 


67-79 


74.93 


4 


69.88 


76.80 


3 


65-71 


73-03 


3 


67.83 


74-97 


3 


69.92 


76.83 


2 


65-75 


73-07 


2 


67.88 


75-OI 


2 


69.96 


76.87 


I 


65-79 


73-11 


I 


67.92 


75-04 


I 


70.00 


76.91 





65-83 


73-15 





67.96 


75-08 





70.04 


76.94 


0.8819 


65.88 


73-19 


0.8769 


68.00 


75-12 


0.8719 


70.08 


76.98 


8 


65.92 


73.22 


8 


68.04 


75-16 


8 


70.12 


77.01 


7 


65-96 


73.26 


7 


68.08 


75-19 


7 


70 16 


77-05 


6 


66.00 


73 30 


6 


68.13 


75-23 


6 


70.20 


77.08 


5 


66.04 


73-34 


5 


68.17 


75-27 


5 


70.24 


77.12 


4 


66.09 


73-38 


4 


68.21 


75-30 


4 


70.28 


77-15 


3 


66.13 


73-42 


3 


68.25 


75-34 


3 


70.32 


77.19 


2 


66.17 


73-46 


2 


68.29 


75-38 


2 


70.36 


77.22 . 


I 


66.22 


73-50 


I 


68.33 


75-42 


I 


70.40 


77-25 





66.26 


73-54 





68.38 


75-45 





70.44 


77-29 


0.8809 


66.30 


73-57 


0.8759 


68.42 


75-49 


0.8709 


70.48 


77-32 


8 


66.35 


73-61 


8 


68.46 


75-53 


8 


70.52 


77-36 


7 


66.39 


73-65 


7 


68.50 


75-57 


7 


70.56 


77-39 


6 


66.43 


73-69 


6 


68.54 


75-60 


6 


70.60 


77-43 


5 


66.48 


73-73 


5 


68.58 


75-64 


5 


70-64 


77-46 


4 


66.52 


73-77 


4 


68.63 


75-68 


4 


70.68 


77-50 


3 


66.57 


73-81 


3 


68.67 


75-72 


3 


70.72 


77-53 


2 


66.61 


73-85 


2 


68.71 


75-75 


2 


70.76 


77-57 


I 


66.65 


73-89 


I 


68.75 


75-79 


I 


70.80 


77.60 





66.70 


73-93 





68.79 


75-83 





70.84 


77-64 


0.8799 


66.74 


73-97 


0.8749 


68.83 


75-87 


0.8699 


70.88 


77.67 


8 


66.78 


74.01 


8 


68.88 


75-90 


8 


70.92 


77.71 


7 


66.83 


74-05 


7 


68.92 


75-94 


7 


70.96 


77-74 


6 


66.87 


74.09 


6 


68.96 


75-98 


6 


71.00 


77-78 


5 


66.91 


74-13 


5 


69.00 


76.01 


5 


71.04 


77-82 


4 


66.96 


74-17 


4 


69.04 


76-05 


4 


71.08 


77-85 


3 


67.00 


74.22 


3 


69.08 


76.09 


3 


7^-'^3 


77.89 


2 


67.04 


74-25 


2 


69.13 


76-13 


2 


71.17 


77-93 


I 


67.08 


74-29 


I 


69.17 


76.16 


I 


71.21 


77.96 





67-13 


74-33 





69.21 


76.20 





71-25 


78.00 


0.8789 


67.17 


74-37 


0.8739 


69-25 


76.24 


0.8689 


71.29 


78.04 


8 


67.21 


74.40 


8 


69.29 


76.27 


8 


71-33 


78-07 


7 


67-25 


74-44 


7 


69-33 


76-31 


7 


71-38 


78.11 


6. 


67.29 


74-48 


6 


69.38 


76.35 


6 


71.42 


78.14 


5 


67-33 


74-52 


5 


69.42 


76.39 


5 


71.46 


78.18 


4 


67-38 


74-55 


4 


69.46 


76.42 


4 


71-50 


78.22 


3 


67.42 


74-59 


3 


69.50 


76.46 


3 


71-54 


78.25 


2 


67.46 


74-63 


2 


69-54 


76-50 


2 


71-58 


78.29 


I 


67.50 


74-67 


I 


69-58 


76.53 


I 


71-63 


78.33 





67-54 


74-70 





69.63 


76-57 





71.67 


78.36 



ALCOHOLIC BEVERAGES. 699 

SPECIFIC GRAVITY AND PERCENTAGE OF Al.COUOL—{Conlinued). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 
Grav. 

of 






Spec. 

Grav. 

at 






Spec. 

Grav. 

at 






Per 


Per 


Per 


Per 


Per 


Per 




Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 




by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


time. 




Weight. 


uine. 


0.8679 


71.71 


78.40 


0.8629 


73-83 


80.26 


0.8579 


76.08 


82.23 


8 


71-75 


78-44 


8 


73-88 


80.30 


8 


76.13 


82.26 


7 


71.79 


78-47 


7 


73-92 


80.33 


7 


76.17 


82.30 


6 


71-83 


78-51 


6 


73-96 


80.37 


6 


76.21 


82.33 


5 


71.88 


78-55 


5 


74.00 


80.40 


5 


76-25 


82.37 


4 


71.92 


78.58 


4 


74-05 


80.44 


4 


76.29 


82.40 


3 


71.96 


78.62 


3 


74-09 


80.48 


3 


76-33 


82.44 


2 


72.00 


78.66 


2 


74.14 


80.52 


2 


76.38 


82.47 


I 


72.04 


78.70 


I 


74.18 


80.56 


I 


76.42 


82.51 





72.09 


78-73 





74-23 


80.60 





76.46 


82.54 


0.8669 


72-13 


78.77 


0.8619 


74.27 


80.64 


0.8569 


76.50 


82.58 


8 


72.17 


78.81 


8 


74-32 


80.68 


8 


76-54 


82.61 


7 


72.22 


78.85 


7 


74-36 


80.72 


7 


76.58 


82.65 


6 


72.26 


78.89 


6 


74.41 


80.76 


6 


76-63 


82.69 


5 


72.30 


78.93 


5 


74-45 


80.80 


5 


76.67 


82.72 


4 


72-35 


78.96 


4 


74-50 


80.84 


4 


76.71 


82.76 


3 


72-39 


79.00 


3 


74-55 


80.88 


3 


76-75 


82.79 


2 


72.43 


79.04 


2 


74-59 


80.92 


2 


76-79 


82.83 


I 


72.48 


79.08 


I 


74.64 


80.96 


I 


76.83 


82.86 





72.52 


79.12 





74.68 


81.00 





76.88 


82.90 


0.8659 


72-57 


79.16 


0.8609 


74-73 


81.04 


0-8559 


76.92 


82.93 


8 


72.61 


79.19 


8 


74-77 


81.08 


8 


76.96 


82.97 


7 


72.65 


79-23 


7 


74.82 


81.12 


7 


77.00 


83.00 


6 


72.70 


79.27 


6 


74.86 


8r.i6 


6 


77.04 


83.04 


5 


72.74 


79-31 


5 


74-91 


81.20 


5 


77.08 


83-07 


4 


72.78 


79-35 


4 


74-95 


81.24 


4 


77-13 


83.11 


3 


72.83 


79-39 


3 


75.00 


81.28 


3 


77.17 


83.14 


2 


72.87 


79.42 


2 


75-05 


81.32 


2 


77.21 


83.18 


I 


72.91 


79.46 


I 


75-09 


81.36 


I 


77-25 


83.21 





72.96 


79-50 ; 





75-14 


81.40 





77.29 


83-25 


0.8649 


73.00 


79-54 


0.8599 


75-18 


81.44 


0.8549 


77-33 


83.28 


8 


73-04 


79-57 


8 


75-23 


81.48 


8 


77-38 


83-32 


7 


73.08 


79-61 


7 


75-27 


81.52 


7 


77-42 


83.36 


6 


73-13 


79-65 ! 


6 


75-33 


81.56 


6 


77.46 


83-39 


5 


73-17 


79.68 


5 


75-36 


81.60 


5 


77-50 


83-43 


4 


73-21 


79.72 


4 


75-41 


81.64 


4 


77-54 


83.46 


3 


73-25 


79-75 


3 


75-45 


81.68 


3 


77-58 


83-50 


2 


73-29 


79-79 


2 


75-50 


81.72 


2 


77-63 


83-53 


I 


73-33 


79-83 


I 


75-55 


81.76 


I 


77-67 


83-57 





73-38 


79.86 





75-59 


81.80 





77.71 


83.60 


0,8639 


73-42 


79-90 


0.8589 


75-64 


81.84 


0-8539 


77-75 


83.64 


8 


73-46 


79-94 


8 


75-68 


81.88 


8 


77-79 


83-67 


7 


73-50 


79-97 


7 


75-73 


81.92 


7 


77-83 


83-71 


6 


73-54 


80.01 


6 


75-77 


81.96 


6 


77.88 


83-74 


5 


73-58 


80.04 


5 


75-82 


82.00 


5 


77-92 


83.78 


4 


73-63 


80.08 


4 


75-86 


82.04 


4 


77-96 


83.81 


3 


73-67 


80.12 


3 


75-91 


82.08 


3 


78.00 


83-85 


2 


73-71 


80-15 


2 


75-95 


82.12 


2 


78.04 


83.88 


I 


73-75 


80.19 


I 


76.00 


82.16 


I 


78.08 


83.91 





73-79 


80.22 





76.04 


82.19 





78.12 


83-94 



700 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF ALCOB.O'L— (Continued). 



Spec. 
Grav. 

at 
iS.6°C. 



Absolute Alcohol. 



Per 

Cent 

by 

Weight. 



0.8529 


78. 


8 


78. 


7 


78. 


6 


78. 


5 


78. 


4 


78. 


3 


78. 


2 


78. 


I 


78. 





78. 


0.8519 


78. 


8 


78. 


7 


78. 


6 


78. 


5 


78. 


4 


78. 


3 


78. 


2 


78. 


I 


78. 





78. 


0.8509 


78. 


8 


79- 


7 


79- 


6 


79- 


5 


79- 


4 


79- 


3 


79- 


2 


79- 


I 


79- 





79- 


0,8499 


79- 


8 


79- 


7 


79- 


6 


79- 


5 


79- 


4 


79- 


3 


79- 


2 


79- 


I 


79- 





79- 


0.8489 


79- 


8 


79- 


7 


79- 


6 


79- 


5 


79- 


4 


79- 


3 


80. 


2 


80. 


I 


80. 





80. 



Per 
Cent, 
by Vol- 
ume. 



83.98 
84.01 
84.04 
84.08 
84.11 
84.14 
84.18 
84.21 
84.24 
84.27 

84.31 
84-34 
84-37 
84.41 
84.44 

84.47 
84.51 
84-54 
84-57 
84.60 

84.64 
84.67 
84.70 
84-74 
84.77 
84.80 
84.83 
84.87 
84.90 
84-93 

84.97 
85.00 

85-03 
85.06 
85.10 

85-13 
85.16 
85.19 

85-23 
85.26 

85.29 
85-33 
85-36 
85-39 
85-42 
85.46 
85-49 
85-53 
85-56 
85-59 



Spec. 
Grav. 

at 
15.6° C. 



0.8479 
8 

7 
6 

5 
4 
3 



0.8469 
8 

7 
6 

5 
4 
3 



0.8459 
8 

7 
6 

5 
4 
3 



.8449 
8 

7 
6 

5 
4 
3 



0.8439 
8 

7 
6 

5 
4 
3 



Absolute Alcohol. 



Per 

Cent 

by 

Weight. 



Per 

Cent 
by Vol- 
ume. 



15 



Spec. 
Grav. 

at 
:S.6°C. 



0.8429 
8 

7 
6 

5 
4 
3 



0.0419 
8 

7 
6 

5 
4 
3 



0.8409 
8 

7 
6 

5 
4 
3 



0.8399 
8 

7 
6 

5 
4 
3 



0.8: 



Absolute Alcohol. 



Per 
Cent 

by 
Weight. 



82.19 
82.23 
82.27 
82.31 

82.35 
82.38 
82.42 
82.46 
82.50 
82.54 

82.58 
82.62 
82.65 
82.69 

82.73 
82.77 
82-81 
82.85 
82.88 
82.92 

82.96 
83.00 
83.04 
83.08 
83.12 

83-iS 
83.19 

83-23 
83-27 
83-31 

83-35 
83-38 
S3. 42 
83.46 
83-50 
83-54 
83-58 
83.62 

83-65 
83.69 

83-73 
83-77 
83-81 

83-85 
83.88 
83.92 
83.96 
84.00 
84.04 
84-08 



Per 
Cent 

by Vol- 
ume. 



88 



ALCOHOLIC BEVERAGES. 



701 



SPECIFIC GRAVITY AND PERCENTAGE OF Al.COHO'L— (Continued). 



Spec. 
Grav. 

at 


Absolute Alcohol. 


Spec. 

Grav. 

at 


Absolute Alcohol. 


Spec. 
Grav. 

at 


Absolute Alcohol. 


Per 


Per 


Per 


Per 


Per 


Per 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


iS.6°C. 


Cent 


Cent. 


by 


by Vol- 




by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




"Weight. 


ume. 




Weight. 


ume. 


0.8379 


84.12 


88.79 


0.8329 


86.08 


90.32 


0.8279 


88.00 


91.78 


8 


84.16 


88.83 


8 


86.12 


90-35 


8 


88.04 


91.81 


7 


84.20 


88.86 


7 


86-15 


90.38 


7 


88.08 


91.84 


6 


84.24 


88-89 


6 


86-19 


90.40 


6 


88.12 


91.87 


5 


84.28 


88.92 


5 


86.23 


90-43 


5 


88.16 


91.90 


4 


84.32 


88.95 


4 


86.27 


90.46 


4 


88.20 


91-93 


3 


84-36 


88.98 


3 


86.31 


90.49 


3 


88.24 


91.96 


2 


84.40 


89.01 


2 


86.35 


90.52 


2 


88.28 


91.99 


I 


84.44 


89.05 


I 


86.38 


90-55 


I 


88.32 


92-02 





84.48 


89.08 





86.42 


90-58 





88.36 


92.05 


0.8369 


84-52 


89.11 


0.8319 


86.46 


90-61 


0.8269 


88.40 


92.08 


8 


84-56 


89.14 


8 


86.50 


90-64 


8 


88.44 


92.12 


7 


84.60 


89-17 


7 


86.54 


90.67 


7 


88.48 


92-15 


6 


84.64 


89.20 


6 


86.58 


90-70 1 


6 


88.52 


92.18 


5 


84.68 


89.24 


5 


86.62 


90-73 


5 


88-56 


92-21 


4 


84.72 


89.27 


4 


86.65 


90.76 


4 


88.60 


92.24 


3 


84.76 


89.30 


3 


86.69 


90.79 


3 


88.64 


92.27 


2 


84.80 


89-33 


2 


86.73 


90.82 


2 


88.68 


92-30 


I 


84.84 


89.36 


I 


86.77 


90.85 


I 


88.72 


92-33 





84.88 


89-39 





86.81 


90.88 





88.76 


92.36 


0.8359 


84.92 


89.42 


0.8309 


86.85 


90.90 


0.8259 


88-80 


92-39 


8 


84.96 


89-46 


8 


86.88 


90-93 


8 


88.84 


92.42 


7 


85.00 


89.49 


7 


86.92 


90.96 


7 


88.88 


92-45 


6 


85.04 


89 52 


6 


86.96 


90-99 


6 


88.92 


92.48 


5 


85.08 


89-55 


5 


87.00 


91.02 


5 


88.96 


92-51 


4 


85.12 


89.58 


4 


87.04 


91-05 


4 


89.00 


92-54 


3 


85-15 


89.61 


3 


87.08 


91.08 


3 


89.04 


92.57 


2 


85.19 


89-64 


2 


87.12 


91. II 


2 


89.08 


92.60 


I 


85-23 


89-67 


I 


87-15 


91.14 


I 


89.12 


92-63 





85-27 


89.70 





87.19 


91.17 





89.16 


92.66 


0.8349 


85-31 


89.72 


0.8299 


87-23 


91.20 


0.8249 


89.19 


92-68 


8 


85-35 


89-75 


8 


87-27 


91-23 


8 


89-23 


92.71 


7 


85-38 


89.78 


7 


87-31 


91-25 


7 


89.27 


92.74 


6 


85.42 


89.81 


6 


87-35 


91.28 


6 


89.31 


92.77 


5 


85.46 


89.84 


5 


87-38 


91-31 


5 


89-35 


92.80 


4 


85-50 


89.87 


4 


87-42 


91-34 


4 


89.38 


92-83 


3 


85-54 


89.90 


3 


87.46 


91-37 


3 


89.42 


92.86 


2 


85-58 


89-93 


2 


87.50 


91.40 


2 


89.46 


92.89 


I 


85.62 


89.96 


I 


87-54 


91-43 


I 


89-50 


92.91 





85-65 


89-99 





87-58 


91.46 





89-54 


92.94 


0-8339 


85.69 


90.02 


0.8289 


87.62 


91.49 


0.8239 


89-58 


92.97 


8 


85-73 


90.05 


8 


87.65 


91-52 


8 


89.62 


93.00 


7 


85-77 


90.08 


7 


87.69 


91-55 


7 


89.65 


93-03 


6 


85.81 


90.11 


6 


87-73 


91-57 


6 


89.69 


93.06 


5 


85-85 


90.14 


5 


87.77 


91.60 


5 


89-73 


93-09 


4 


85.88 


90-17 


4 


87.81 


91.63 


4 


89-77 


93-11 


3 


85.92 


90.20 


3 


87.85 


91 -66 


3 


89.81 


93-14 


2 


85.96 


90.23 


2 


87.88 


91.69 


2 


89.85 


93-17 


I 


86.00 


90.26 


I 


87.92 


91.72 


I 


89.88 


93-20 





86.04 


90.29 





87.96 


91-75 





89.92 


93-23 



702 FOOD INSPECTION AND ANALYSIS. 

SPECIFIC GRAVITY AND PERCENTAGE OF AJ.COnO'L— (Continued). 





Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 


Spec. 






Spec. 






Spec. 


















Grav. 

at 

teft°C 


Per 


Per 


Grav. 

at 


Per 


Per 


Grav. 

at 


Per 


Per 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15.6° C. 


Cent 


Cent 


15. u \^. 


by 


by Vol- 


by 


by Vol- 


by 


by Vol- 




Weight. 


ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8229 


89.96 


93.26 


0.8179 


91-75 


94-53 


0.8129 


93-59 


95-84 


8 


90.00 


93-29 


8 


91.79 


94-56 


8 


93-63 


95-87 


7 


90.04 


93-31 


7 


91.82 


94-59 


7 


93-67 


95-90 


6 


90.07 


93-34 


6 


91.86 


94.61 


6 


93-70 


95-92 


5 


90.11 


93-36 


5 


91.89 


94.64 


5 


93-74 


95-95 


4 


90.14 


93-39 


4 


91-93 


94.66 


4 


93-78 


95-97 


3 


90.18 


93-41 


3 


91.96 


94.69 


3 


93-81 


96.00 


2 


90.21 


93-44 


2 


92.00 


94.71 


2 


93-85 


96.03 


I 


90.25 


93-47 


I 


92.04 


94-74 


I 


93-89 


96.05 





90.29 


93-49 





92.07 


94.76 





93-92 


96.08 


0.8210 


90.32 


93-52 


0.8169 


92.11 


94.79 


0.8119 


93-96 


96.11 


8 


90.36 


93-74 


8 


92-15 


94.82 


8 


94.00 


96.13 


7 


90-39 


93-57 


7 


92.18 


94.84 


7 


94-03 


96.16 


6 


90-43 


93-59 


6 


92.22 


94.87 


6 


94-07 


96.18 


5 


90.46 


93.62 


5 


92.26 


94.90 


5 


94.10 


96.20 


4 


90.50 


93-64 


4 


92.30 


94.92 


4 


94.14 


96.22 


3 


90-54 


93-67 


3 


92-33 


94-95 


3 


94.17 


96.25 


2 


90-57 


93-70 


2 


92-37 


94.98 


2 


94.21 


96.27 


I 


90.61 


93-72 


I 


92.41 


95-00 


I 


94-24 


96.29 





90.64 


93-75 





92.44 


95-03 





94.28 


96.32 


0.8209 


90.68 


93-77 


0.8159 


92.48 


95.06 


0.8109 


94-31 


96-34 


8 


90.71 


93.80 


8 


92-52 


95-08 


8 


94-34 


96.36 


7 


90-75 


93.82 


7 


92.55 


95-11 


7 


94.38 


96-39 


6 


90.79 


93-85 


6 


92-59 


95-13 


6 


94.41 


96.41 


S 


90.82 


93-87 


5 


92.63 


95.16 


5 


94-45 


96-43 


4 


9c. 86 


93-9° 


4 


92.67 


95-19 


4 


94.48 


96.46 


3 


90.89 


93-93 


3 


92.70 


95-21 


3 


94-52 


96.48 


2 


90-93 


93-95 


2 


92.74 


95-24 


2 


94-55 


96.50 


I 


90.96 


93-98 


I 


92.78 


95-27 


I 


94-59 


96-53 





91.00 


94.00 





92.81 


95-29 





94.62 


96-55 


0.8199 


91.04 


94-03 


0.8149 


92.85 


95-32 


. 8099 


94-65 


96-57 


8 


91.07 


94-05 


8 


92.89 


95-35 


8 


94-69 


96.60 


7 


91.11 


94.08 


7 


92.92 


95-37 


7 


94-73 


96.62 


6 


91.14 


94.10 


6 


92.96 


95-40 


6 


94-76 


96.64 


5 


91.18 


94-13 


5 


93.00 


95-42 


5 


94.80 


96-67 


4 


91.21 


94-15 


4 


93-04 


95-45 


4 


94-83 


96.69 


3 


91-25 


94.18 


3 


93-07 


95-48 


3 


94.86 


96.71 


2 


91.29 


94.21 


2 


93-11 


95-50 


2 


94.90 


96-74 


I 


91.32 


94-23 


I 


93-15 


95-53 


I 


94-93 


96.76 





91.36 


94-26 





93.18 


95-55 





94-97 


96.78 


0.8189 


91-39 


94-28 


0.8139 


93.22 


95-58 


0.8089 


95-00 


96-80 


8 


91-43 


94-31 


8 


93.26 


95.61 


8 


95-04 


96.83 


7 


91.46 


94-33 


7 


93-30 


95-63 


7 


95-07 


96.85 


6 


91.50 


94-36 


6 


93-33 


95.66 


6 


95- " 


96.88 


5 


91-54 


94-38 


5 


93-37 


95-69 


5 


95-14 


96.90 


4 


91-57 


94.41 


4 


93-41 


95-71 


4 


95.18 


96-93 


3 


91.61 


94-43 


3 


93-44 


95-74 


3 


95-21 


96-95 


2 


91.64 


94-46 


2 


93-48 


95-76 


2 


95-25 


96.98 


I 


91.68 


94-48 


I 


93-52 


95-79 


I 


95-29 


97.00 





91.71 


94-51 





93-55 


95.82 





95-32 


97.02 






ALCOHOLIC BEVERAGES. 



703 



SPECIFIC GRAVITY AND PERCENTAGE OF Al.COUO'L— (Continued). 



Spec. 


Absolute Alcohol. 




Absolute Alcohol. 




Absolute Alcohol. 






Spec. 






Spec. 






Orav 


Per 


Per 


Grav. 


Per 


Per 


Grav. 


Per 


Per 


at 
iS-6°C. 


Cent 
bv 


i Cent 
i by Vol- 


at 
IS.6°C. 


Cent 
by 


Cent 
by Vol- 


at 
15.6° C. 


Cent 
by 


Cent 
by Vol- 




Weight. 


1 ume. 




Weight. 


ume. 




Weight. 


ume. 


0.8079 


95-36 


' 97-05 


0.8029 


97-07 


98.18 


0.7979 


98.69 


99.18 


"^ 


95-39 


97-07 


8 


97.10 


98.20 


8 


98.72 


99.20 


7 


95-43 


97.10 


7 


97-13 


98.22 


7 


98.75 


99.22 


6 


95-46 


1 97-12 


6 


97.16 


98.24 


6 


98.78 


99-24 


5 


95-50 


: 97-15 


5 


97.20 


98.27 


5 


98.81 


99.26 


4 


95-54 


t 97-17 


4 


97-23 


98.29 


4 


98.84 


99.27 


3 


95-57 


97.20 


3 


97.26 


98.31 


3 


98.87 


99-29 


2 


95-61 


1 97.22 


2 


97-30 


98.33 


2 


98.91 


99-31 


I 


95-64 


1 97-24 


I 


97-33 


98-35 


I 


98.94 


99-33 





95.68 


97.27 





97-37 


98-37 





98.97 


99-35 


0.8069 


95-71 


97-29 


0.8019 


97.40 


98-39 


0.7969 


99.00 


99-37 


8 


95-75 


97-32 


8 


97-43 


98.42 


8 


99-03 


99-39 


7 


95-79 


97-34 


7 


97.46 


98-44 


7 


99.06 


99.41 


6 


95-82 


97-37 


6 


97-50 


98.46 


6 


9Q.IO 


99-43 


5 


95-86 


97-39 


5 


97-53 


98.48 


5 


99-13 


99-45 


4 


95-89 


97.41 


4 


97-57 


98.50 


4 


99.16 


99-47 


3 


95-93 


97-44 


3 


97.60 


98.52 


3 


99.19 


99-49 


2 


95-96 


97.46 


2 


97-63 


98-54 


2 


99-23 


99-51 


I 


96.00 


97-49 


I 


97.66 


98-56 


I 


99.26 


99-53 





96.03 


97-51 





97-70 


98-59 





99.29 


99-55 


0.8059 


96.07 


97-53 


0.8009 • 


97-73 


98.61 


0-7959 


99-32 


99-57 


8 


96.10 


97-55 


8 


97-76 


98.63 


8 


' 99.36 


99-59 


7 


96.13 


97-57 


7 


97.80 


98.65 


7 


99-39 


99.61 


6 


96.16 


97.60 


6 


97-83 


98.67 


6 


99-42 


99-63 


S 


96.20 


97.62 


5 


97-87 


98.69 


5 


99-45 


99-65 


4 


96.23 


97.64 


4 


97.90 


98.71 


4 


99.48 


99-67 


3 


96.26 


97.66 


3 


97-93 


98.74 


3 


99-52 


99-69 


2 


96.30 


97.68 


2 


97-96 


98.76 


2 


99-55 


99.71 


I 


96.33 


97.70 


I 


98.00 


98.78 


I 


99-58 


99-73 





96-37 


97-73 





98.03 


98.80 





99.61 


99-75 


0.8049 


96.40 


97-75 


0.7999 


98.06 


98.82 


0.7949 


99-65 


99-77 


8 


96-43 


97-77 


8 


98.09 


98.83 


8 


99.68 


99.80 


7 


96.46 


97-79 


7 


98.12 


98-85 


7 


99.71 


99.82 


6 


96.50 


97.81 


6 


98.16 


98.87 


6 


99-74 


99-84 


5 


96-53 


97-83 


5 


98.19 


98.89 


5 


99-78 


99.86 


4 


96-57 


97.86 


4 


98.22 


98.91 


4 


99.81 


99.88 


3 


96.60 


97.88 


3 


98.25 


98.93 


3 


99-84 


99-90 


2 


96-63 


97.90 


2 


98.28 


98.94 


2 


99.87 


99-92 


1 


96.66 


97-92 


I 


98.31 


98.96 


1 


99.90 


99-94 





96.70 


97-94 





98-34 


98.98 





99-94 


99-96 


0.8039 


96-73 


97.96 


0.7989 


98-37 


99.00 


0.7939 


99-97 


99-98 


8 


96.76 


97.98 


8 


98.41 


99.02 








7 


96.80 


98.01 


7 


98-44 


99.04 




Abs. 


Ale. 


6 


96-83 


98.03 


6 


98-47 


99.05 


0.7938 


100.00 


100.00 


S 


96.87 


98-05 


5 


98.50 


99.07 








4 


96.90 


98.07 


4 


98-53 


99.09 








3 


96-93 


98.09 


3 


98.56 


99-11 








2 


96.96 


98.11 


2 


98-59 


99-13 








I 


97.00 


98.14 


I 


98.62 


99-15 











97-03 


98.16 





98.66 


99.16 









704 



FOOD INSPECTION AND ANALYSIS. 



(4) Determination of Alcohol hy the Ebullioscope or Vaporimeter 
is based on the variation in boiling-point of mixtures of alcohol and water, 
in accordance with the amount of alcohol present. There are various 
forms of this instrument, one of the simplest and most convenient being 
that of Salleron, Fig. 113, the apparatus being known in France as an 




o-^-o 



-^91- 



3-18 
20 



Fig. 113. — Salleron's Ebullioscope and Scale for Calculation of Results. 

ebulliometer. This consists of a jacketed metallic reservoir, healed by 
a lamp placed beneath, and fitted with a return-flow condenser at the 
top and with a delicate thermometer graduated in tenths of a degree. 

As the boiling-point of water varies with the atmospheric pressure, 
it is necessary to determine the actual boiling-point corresponding with 
the barometric conditions each time a series of determinations are made. 



ALCOHOLIC BEVERAGES. 705 

This is done by boiling a measured portion of distilled water in the reser- 
voir, and carefully noting the temperature when it becomes constant. 

The reservoir is then rinsed out with a little of the liquor to be tested, 
after which a measured amount of this liquor is boiled in the reservoir 
and the temperature again noted. A sliding scale (Fig. 113) accompanies 
the instrument, having three graduated parts as shown. The central 
movable portion is graduated in degrees and tenths of a degree centi- 
grade, the part at the left has the per cent of alcohol corresponding to 
the temperature in the case of simple mixtures of alcohol and water, 
while the part at the right is used for reading the per cent in the case of 
wine, cider, beer, etc., which have a considerable residue. The movable 
scale bearing the degrees of temperature is first set with the actual tem- 
perature of boiling water (as ascertained) opposite the o mark on the 
stationary scale. Suppose the temperature of boiling water has been 
found to be 100.1°. The scale is in this case set as shown in Fig. 113. 
Suppose also the temperature of boiling of the wine to be tested is 
found to be 89.3°. From the right-hand scale the corresponding per cent 
of alcohol is found to be 17.2. 

When the liquor to be tested contains more than 25% of alcohol, it 
is necessary to dilute with a measured amount of distilled water and 
calculate the per cent from the dilution. 

When once the boiling-point of water has been determined for a given 
barometric pressure, it is unnecessary to change the position of the slid- 
ing scale during a series of alcohol determinations unless that pressure 
changes. 

Expression of Results. — Some confusion is caused by the three ways 
of expressing results of the alcohol determination, whether as per cent by 
weight, per cent by volume, or grams per 100 cc. The particular mode 
adopted should depend upon the nature of the case and upon the prevail- 
ing custom. In laboratory analyses, unless otherwise qualified, the simple 
expression of "per cent" usually implies per cent by weight, and for 
the reason that this conforms with other determinations, the adoption 
of the weight-percentage plan is perhaps most natural to the chemist on 
the grounds of uniformity. 

In enforcing the laws regulating the liquor traffic, the custom leans 
to volume percentage, and many of the laws are based on the ' ' volume 
of alcohol at 60° F." (see page 685). 

In recent years many European analysts have adopted the custom of 
expressing results of analyses of wines and other liquors in grams per 



706 FOOD INSPECTION AND ANALYSIS. 

loo cc. and, in order to have a common basis of comparison between 
the composition of American and of European wines, this manner of 
expression has to some extent been adopted in the United States. 

Proofs pirit in the United States is an alcoholic liquor containing 50% 
of absolute alcohol by volume at 15.6° C. A common method of express- 
ing alcohol is in "degree proof" or simply " proof," which in the United 
States is twice the per cent of alcohol by volume. Ihus, 91.3 proof or 
degree proof is the same as 45.65% alcohol by volume. 

English Proof-spirit differs from that in the United States in that it 
contains 49.24% by weight, or 57.06% by volume of absolute alcohol at 
15.6° C. Strength is expressed in degrees over or under proof. Thus 
liquor 20° under proof has 80 parts by volume of proof-spirit and 20 parts 
of water at 15.6° C, while 20° over-proof means that 100 volumes of the 
liquor have to be diluted to 120 volumes with water to yield proof-spirit. 
To calculate the per cent by volume of English proof-spirit from the per 
cent of alcohol by volume, divide the latter by 0.5706, or multiply it by 

I-7525- 

Direct Determination of Extract. — In liquors having a high sugar 
content, the extract or total solids cannot be determined accurately by 
evaporation at the temperature of boiling water, owing to the dehydra- 
tion of the reducing sugars at temperatures exceeding 75°. When extreme 
accuracy is required, such liquors should be dried in vacuo at 75°, or in 
a McGill oven (page 609). 

In the case of dry wines having an extract content of less than 3% 
evaporate 50 cc. in a flat-bottom platinum dish 85 mm. in diameter to a 
syrup on the water bath and dry for two and one-half hours at the tem- 
perature of boiling water. Sweet wines with an extract of from 3 to 6% 
are treated in the same manner, using, however, only 25 cc. With sweet 
wines containing over 6% of extract calculate from the specific gravity of 
the dealcoholized liquor (page 726). 

With distilled liquors having low residues accurate results are obtain- 
able by direct evaporation at 100° (page 777). 

Determination of Ash. — The residue from the determination of the 
extract is incinerated to a white ash in the original dish at a low red heat, 
either over a Bunsen flame or in a muffle. The dish is finally cooled in 
a desiccator and weighed. 

Preservatives and Artificial Sweeteners in liquors are identified as 
described in Chapters XVIII and XIX. 



ALCOHOLIC BEVERAGES. 



707 



FERMENTED LIQUORS. . 

The fermented juices of many varieties of fruits and berries furnish 
beverages more or less popular in various localities, especially for home 
consumption, though, with the exception of the products of the apple and 
the grape, few of them are found on the market. The following table 
shows the average percentage of sugar and free acid in the expressed 
juice or must of fruits, according to Fresenius, arranged in the order 
of their sugar content: 





Per Cent Sugar. 


Per Cent Free 
Acid as Malic. 


Peaches 


1-99 
2.13 
2.80 
4-18 
4.84 
S-32 
6.89 

7-3° 
7-56 
8.00 

8-43 

9.14 

10.00 

10.44 

15-30 
16.15 


0.85 
1.29 
1.72 
0.67 
1.80 
1.42 
1-57 
2-43 
1.08 
1.63 
0.09 
0.82 
2.02 
1.52 
0.88 
0.80 


Apricots 


Plums 


Green gages . . , 

Raspberries 


Blackberries 




Currants 


German prunes 

Gooseberries 


Pears 


Apples 


Mulberries 


Sour cherries 




Grapes 





CIDER. 

Cider is the expressed juice of the apple. When fresh and before 
fermentation has set in, it is known as sweet cider, but it does not long 
remain in this condition, developing after a good fermentation from 3 to 
6 per cent of alcohol by volume. 

The predominating yeast under the influence of which the fermenta- 
tion of cider takes place is Saccharomyces apiculatus, found in consider- 
able quantity on the outside of the apples as well as in the soil in which 
the trees grow. 

Process of Manufacture. — The best cider is made from ripe fruit, 
taking care to avoid the green and the rotten apples, both of which impair 
the quality of the product. After gathering, the apples are best allowed tc 
Stand in piles. until perfectly ripe, being kept under cover. If exposed 
to the weather, certain of the yeast organisms found on the skins of the 
apples that are useful in promoting subsequent fermentation would b€ 



708 FOOD INSPECTION AND ANALYSIS. 

washed off. As a rule the apples commonly used by farmers for cider- 
making are those that are unsalable or unfit for other purposes, being 
chiefly windfalls or bruised and imperfect fruit. The apples aie usually 
first crushed in a mill to a coarse pulp, which is afterward subjected to 
pressure in a suitable press and the juice thus extracted. 

In this country but little attention is paid to the after processes, the 
juice being usually transferred directly to barrels, which are not always 
particularly clean, and allowed to ferment spontaneously in a convenient 
place, subject to changes in temperature. There is little wonder that 
cider so made will keep but a short time and quickly goes over into vinegar, 
unless sahcylic acid or other antiseptic is added. 

In France more care is taken to regulate the temperature of fermen- 
tation, to insure absolute cleanness of all receptacles, and to separate 
out contaminating impurities. A preliminary fermentation is usually 
given to the juice in open vats, during which the yeast spores are 
developed, while impurities separate out both by rising to the surface 
and by settling to the bottom, care being taken to avoid the develop- 
ment of acetic fermentation. At the proper time the juice is "racked 
off" or drawn from the clear portion between the top and bottom, trans- 
ferred to scrupulously clean barrels, and allowed to undergo a second 
fermentation at a lower temperature than before. 

Sometimes the "racking off" is repeated, and the juice is further 
clarified by "fining" or treating with isinglass, which carries down certain 
albuminous substances. 

Cider thus made is capable of keeping a very long time. 

In England cider is sometimes "fined" by treatment with milk, one 
quart of the latter being added to eighteen gallons of cider. 

The apple pomace, left as a residue, is generally steeped in water 
and repressed. The juice from the second pressing is occasionally added 
to the first for cider manufacture, but more often is concentrated and 
made into apple jelly, or used as a fortifier for vinegar to make up 
deficiency in solids. 

Composition of Cider. — The following tables, due to Browne,* show 
the chemical composition of the freshly expressed juice of several 
American varieties of apple, as well as that of a few fermented samples 
of cider of known purity. 

* Penn. Dept. of Agric, Bui. 58. 



ALCOHOLIC BEVERAGES. 



709 



APPLE JUICES. 



aO 



CS BO 

Pli 





•a 

0) . 

.S " 

■g (U 


< 


(1) a 
•a g 

^0. 


0-37 
0.28 


0.77 
0.65 


0.27 


0.44 


0.24 


I. II 


0.31 


1.22 


0.26 


0.87 


0.28 


1.07 


0.28 


0.66 


0.24 


0.49 


0.26 


0.22 



g 0) a> 
5 - . oi 



Red astrachan . . . . 

Early harvest 

Yellow transparent 
Early strawberry. . 

Sweet bough 

Baldwin, green. ... 

' ' ripe 

Ben Davis 

Bellflower 

Tulpahocken 

Unknown 



1-05317 
1.05522 
1.05020 
1.04949 
1.04979 
1.04882 
1.07362 
1.05389 
1.06270 
1.05727 
I. 05901 



11.78 
13.29 
ir.71 
II. 81 
11.87 
II .36 
16.82 
12.77 
14.90 
13-94 
13.75 



6.87 


3- 


7-49 
8.03 


3- 
2. 


5-47 
7.61 
6 96 


4- 

3- 
I. 


7-97 


7- 


7. II 
9.06 
9.68 


3- 
4- 
3- 


10.52 


2. 



.50,10 

.46 



10.14 



15 



.69 

•59 
.02 
.96 
13-38 
12.79 
12.83 



.14 
.90 
.86 
.78 
.10 
.24 
.67 
.46 
-58 
.26 
.44 



23.72 
24.32 

19.24 
39-40 
36.16 

49.00 
39.20 
48.20 
44.18 



FERMENTED CIDER (MIXED APPLES). 





















Rotation, 




Specific 
Gravity. 


Solids. 


Invert 
Sugar. 


Malic 
Acid. 


Acetic 
Acid. 


Alcohol. 


Pectin. 


Ash. 


400-mm. 

Tube, 
Ventzke 

Scale. 
Degrees 

to the 

Left. 


A... 


i.9q805 


1-94 


0.19 


0.21 


0.2/1 


6.85 


0.03 


0.25 


2.30 


B... 
C... 


I. 00122 
1.00525 


2.71 
3.26 


0.19 
0.89 


0.24 
0.30 


0.42 
0.48 


5-13 
4.67 


0.03 
0.05 


0.32 
0.29 


2-49 
5.28 


D. . 
E... 


I. 0007 I 
I. 00512 


1-93 
2.71 


0.34 
0.24 


0.27 
0.29 


0.21 
1.96 


4-95 
4.26 


0.05 
0.06 


0.23 
0.36 


2.00 
1.76 



The following are summaries of the results of a large number of 
analyses of European apple juices made by Truelle, the quantities being 
expressed in grams per liter: 



Specific gravity 

Inveri mgar 

Sucrose 

Total fermentable sugars (as dextrose) 

Tannin 

Pectin and albuminous substances. . . . 
Acidity (sulphuric acid) 



Mean. 


Minimum. 


Maximum. 


1.0760 


1-0573 


1. 1 100 


135-85 


108.38 


181. 81 


25.01 


5-58 


71.7 


162.18 


119.22 


231-57 


2.90 


0.26 


8.07 


12 





23 


2.14 


0.69 


7.41 



710 



FOOD INSPECTION AND ANALYSIS. 



In the municipal laboratory of Paris, Sangle Ferriere has analyzed 
eleven samples of known-purity cider with the following results: 











Sugar per 








Acidity as 










Liter. 








H2SO4. 






>> 






c 




















.Q 


a 










^ a 








c 


£2g 




efore 
[n ver- 
sion. 


fter 

Inver- 
sion. 




u 

•S3 




,0 






Q 


cw 


a 


m 


<; 


Pu 


<; 


< 


H 


Ph 


Mean 


I. 0159 


3-9 


52.67 


21.31 


21.62 


-4°.26 


3.26 


2.^6 


5-27 


2-55 


Maximum 


I. 0410 


6.2 


114.00 


59-40 


60.80 


-11°. 20 


4-32 


3-68 


6.59 


2.94 


Minimum. . . 


I. 0012 


I.I 


22.62 


Trace 


Trace 





2.48 


2. 04 


4.20 


1-47 



Six samples of bottled "sweet" cider purchased in Massachusetts 
were analyzed in the Food and Drug Laboratory of the Board of Health 
with the following results: 



Per Cent 

Alcohol by 

Weight. 



Per Cent 
Acid as 
Malic. 



Per Cent 
Extract. 



Maximum 
Minimum 
Average.. 



8.00 
3-55 
5-71 



0.72 
0.48 
C.58 



7.82 
2.42 
4.19 



Browne gives the following as the composition of the mixed ash of 
several varieties of apple: 



Ingredient. 



Per- 
cent- 
age. 



Ingredient. 



Per- 
cent- 
age. 



Potash (K2O) 

Soda (NaP) 

Lime (CaO) 

Magnesia (MgO) 

Oxide of iron (FcoOg) 

Oxide of aluminum (AI2O3) 

Chlorine (CI) 

Silica (SiOj) 

Sulphuric acid (SO3) 

Phosphoric acid (P2O5) 

Carbonic acid (COj) 

Deduct oxygen equivalent to CI. . 
Total 



55-94 
0.31 

4-43 
3-78 
O.Q5 
0.80 

0-39 
0.40 
2.66 
8.64 
21.60 



99.90 
.09 



99. Si 



Potassium carbonate (KoCOg)... 
Potassium phosphate (K3PO4). .. 

Sodium chloride (NaCl) 

Calcium sulphate (CaSO^) 

Calcium oxide (CaO) 

Magnesium phosphate (MgjPjO^) 

Magnesium oxide (MgO) 

Ferric oxide (FeoOj") 

Aluminum oxide (AlgO^) 

Silica (SiOg) 

Total 



6.85 

14-5S 
0.60 

4-52 
2.57 
6.97 
0.59 
o-gS 
0.80 
0.40 



99.80 



ALCOHOLIC BEVERAGES. 711 

Burcker * gives the following composition of the ash of cider: 

Per Cent. 

Silica o . 94 

Phosphoric acid 12 .68 

Lime 2.77 

Magnesia 2 .05 

Oxides of iron and manganese o- 94 

Potash 53.74 

Soda 1 . 10 

Carbonic acid 25 . 78 



100.00 



Adulteration of Cider. — ^The Committee on Standards of the A. O. A. C. 

have submitted for adoption the following standards for cider: Alcohol 
not more than 8%, extract not less than 1.8% determined by evaporation 
in an open vessel at ordinary atmospheric pressure and at the tempera- 
ture of boiling water; ash not less than 0.2%. 

Entirely factitious cider made from other than apple stock is rarely 
found, though the product as sold is frequently of inferior quality and 
adulterated. The chief adulterants are water and sugar, and the use of 
antiseptics is common, especially of salicylic and sulphurous acids, sodium 
benzoate, and occasionally beta-naphthol. 

Sodium carbonate is sometimes added to cider to neutralize the acid 
and thus prevent acetic fermentation. An abnormally high ash (say 
in excess of 0.35%) would point toward the presence of added alkali. 

Watering is apparent when the content of alcohol, solids, and ash of 
the suspected sample are found to be considerably below the corre- 
sponding constants of pure cider. x\ccording to Sangle Ferriere, the 
following are the minimum figures for these constants in a pure cider, 
so that a sample may safely be pronounced as watered if they all 
run distinctly below: 

Alcohol 3% by volume 

Extract 1.8% 

Ash 0.17% 

Besides these determinations, it is useful also to determine the fixed 
and volatile acids. 

Caramel is to be looked for, especially in watered samples. Other 

* Les Falsifications des Substances Alimentaires, p. 176. 



712 



FOOD INSPECTION AND ANALYSIS. 



adulterants alleged to be of frequent occurrence in French cider, but 
not commonly found in this country are commercial glucose, tartaric acid 
(to increase the acidity of a watered product), and coal-tar colors. 

Absence or deficiency of malates is conclusive evidence of fraud, 
indicating the admixture of notable quantities of the juice of the second 
pressing of pomace. 

Sugar is rendered apparent by the right-handed polarization of the 
sample, pure cider always polarizing well to the left. If after inversion 
of a dextro-rotary cider the polarization is still to the right, commercial 
glucose is indicated; if the reading after inversion is to the left, cane 
sugar has undoubtedly been added. 

Frequently the analyst has only to determine the alcohol, especially 
in cases of seizure, to ascertain whether or not there has been violation 
of the liquor laws. 

PERRY OR PEAR CIDER. 

This is a common French product, but is rarely if ever found on sale 
in this country, though sometimes made for home consumption. In 
composition and in method of manufacture it much resembles apple 
cider. It is also subject to the same forms of adulteration. 

The following table summarizes a number of analyses made by 
Truelle on pear juice, or must, amounts being expressed in parts per 
thousand : 



Specific gravity 

Invert sugar 

Sucrose 

Total fermentable sugars (as dextrose) 
Tannin 

Pectin and albuminous substances — 
Acidity (as sulphuric acid) 



Mean. 



I . 0845 
145.64 

36-74 
184.14 

1.78 
13.08 

1-47 



Maximum. 



1.0675 

108. ID 

16. 6() 

143-78 
1. 01 

3 
0.76 



Minimum. 



1.0980 
200 

61.41 
220 
^.20 
18 
2.40 



The following analysis of champagne perry is taken from the Lancet 
of October i, 1892: 

Alcohol by weight 1.45 

Alcohol by volume i . 80 

Solids II .00 

Ash 0.35 



ALCOHOLIC BEVERAGES. 713 

WINE. 
Wine in its broadest sense is the fermented expressed juice of any 
fruit, though the term, unless otherwise restricted, is generally understood 
to apply to the juice of the grape. 

The organism present in grape juice that plays the chief part in its 
alcoholic fermentation is the Saccharomyces ellipsoideus, a yeast which 
exists on the skins of the grape. 

Process of Manufacture. — The grapes, which should be fully ripe, 
are picked and sometimes sorted, according to the care that is taken in 
grading the product. They are also sometimes freed from the stems, 
which contain considerable tannic acid, and which when crushed with the 
grapes impart a certain astringency to the final product. The grapes are 
crushed either by machinery or by the bare feet, and the juice is pressed 
out from the pulp in various ways, by screw or hydraulic press, or by the 
centrifugal process. 

A certain amount of juice runs off from the preliminary crushing 
known as the first run, and makes the choicest wine. The product from 
the pressure constitutes the second run, after which the pomace, by steep- 
ing in water and repressing, is made to yield an inferior juice used in 
making piquette. 

Red wines are made from dark grapes by fermenting the pulp, before 
pressing, with the skins, which by this treatment yield up their rich color 
(cenocyanin) to the juice. ■ Besides the color, the skins contain also tannin. 
White wine is made from the pressed pulp, freed from the skins at once, 
or from the pulp of white grapes. The unfermented must constitutes 
from 60 to 80 per cent of the weight of the grape. 

Fermentation progresses most rapidly at a temperature between 25° 
and 30° C, but wine having a much finer boucj[uet is produced by slower 
fermentation, hence the must is allowed to ferment in open vats or tubs 
in cool cellars, at a temperature of from 5° to 20° till it settles out com- 
paratively clear, special care being taken to avoid development of acetic 
fermentation. At the end of the first or active fermentation, the wine 
is drawn off and allowed to undergo a second or slow fermentation in 
casks, during which most of the lees or crude argols, composed of potas- 
sium bitartrate, settle out, being insoluble in alcohol, and the characteristic 
bouquet or flavor of the wine is developed. Occasionally during this 
process the wine is racked or drawn off. 

Undesirable fermentations and vegetable fungus growth, which are 
liable to occur at this time, are avoided by using especially clean casks, 



714 FOOD INSPECTION AND ANALYSIS. 

which are frequently " sulphured " (or burnt out with sulphur) before 
being used. The wine is often clarified, by treatment with gelatin, which 
mechanically removes many impurities by precipitation, or is subjected 
to pasteurization before finally being bottled or stored in casks. 

Classification of Wines. — Natural wines are those which are exclusively 
the product of the simple juice, fermented under the best conditions, either 
till the sugar has been used up, or till the protein is exhausted, or until 
the yeast growth has been checked by the strength of the alcohol developed. 
When the alcohol reaches i8% by volume (in extreme cases 20%) fermen- 
tation due to yeast ceases. Examples of natural wines are hock and claret. 
Fortified wines are those to which alcohol has been added. As the 
addition is commonly made before the fermentation is complete, such 
wines are usually sweet. Examples of fortified wines are madeira, sherry 
and port. 

Still wines are those in which there is but little carbon dioxide remain- 
ing, so that they do not effervesce. Sparkling wines are more or less 
heavily charged with carbon dioxide, either naturally, as in the case of 
champagne, wherein the gas is formed by after fermentation of added 
sugar in the corked bottle, or artificially, by carbonating. 

Wines are also classified according to color. Red wines include clarets, 
chianti and red burgundies, while white wines are those of a yellowish 
color such as the Rhenish and Moselle wines and the sauternes. 

" Dry " wines are those in which the sugar has been exhausted by 
fermentation, while sweet wines possess a considerable amount of unfer- 
mented sugar which remains after the yeast ceases to grow because of the 
exhaustion of the protein or else the formation or addition of an excess 
of alcohol. Sweet wines are often reinforced by the addition of sugar. 

Dealcoholized wine is prepared by distilling off the esters at a low 
temperature and then the alcohol at a higher temperature, returning the 
esters to the residue and charging the whole with carbon dioxide and adding 
a little sugar and in some cases tartaric acid. The product contains a 
negligible amount of alcohol. 

Varieties of Wine. — Champagne according to French law is the 
sparkling wine made in the old province of Champagne, although similar 
wines of other provinces and countries are often incorrectly designated 
by that name. It is prepared from selected white wine clarified with 
gelatine, bottled with the addition of cane-sugar and tightly corked. 
The bottles are placed on their sides and fermentation is allowed to pro- 
ceed, thus charging the wine with carbon dioxide. The bottles are then 



ALCOHOLIC BEVERAGES. 715 

gradually inverted until the sediment gathers above the cork, which by care- 
ful manipulation is quickly removed so as to throw out the sediment. A 
small amount of a lic^ueur prepared from sugar, wine and brandy is then 
added, after which the cork is replaced and secured. Champagne con- 
tains from 8 to io% of alcohol and varying amounts of sugar as indicated 
by the designation sec (dry), extra sec and brut (natural). 

Sauternes are sweetish white French wines containing 8 to 14% of 
alcohol by volume and varying amounts of sugar up to 2.5%. Chateau 
Yquem is a well-known sauterne. 

Rhine Wines (Hocks) and Moselle Wines are prized because of their 
delicate mildly tart flavor. They contain little sugar and from 7 to 13% 
of alcohol. Johannisberger, Steinberger, Hochheimer, Liebfraumilch, 
Niersteiner and Rudesheimer are well-known hocks, and Zeltinger and 
Berncasteler Doctor are examples of moselles. 

Claret is the common designation for French red wines produced 
in the neighborhood of Bordeaux, It is somewhat acid and astringent, 
contains 7 to 13% by volume of alcohol and very Httle sugar, St. Julien, 
Pontet Canet, Lafitte, and St. Estephe are well-known examples. 

Burgundies are somewhat heavier wines than the clarets and are 
both red and white, still and sparkling. The best are produced in the 
Cote d'Or of the old province of Burgundy, 

Chianti is an Italian wine similar in flavor to the burgundies. It 
is commonly sold in wicker-covered flasks. 

Red and white natural wines are also produced in other European 
countries as well as in the United States. 

Sherry is a deep-amber-colored sweet Spanish wine high in alcohol 
(18-24% by vol.) and consequently fortified. It is commonly plas- 
tered. 

Port is a sweet Portuguese wine, fortified with brandy, containing 
from 15 to 24% of alcohol by volume. It may be either red or white. 
Its name is a corruption of Oporto, 

Madeira is a rich wine, much improved by age, containing from 18 to 
20% by vol. of alcohol and a marked quantity of sugar. It is named 
from the island producing it, 

Tokay Wines are choice medicinal Hungarian wines high in alcohol 
and very sweet. 

The Constituents of Wine may be classified as volatile organic, non- 
volatile organic, and mineral. The volatile organic constituents, aside 
from ethyl alcohol, consist of higher alcohols, notably amyl alcohol, which 



716 FOOD INSPECTION AND ANALYSIS. 

go to form the fusel oil of brandy, traces of methyl alcohol, volatile acids, 
chiefly acetic acid which is present to some extent in carefully prepared 
wines and in large amount in wines which have undergone acetic fer- 
mentation, also minute quantities of proprionic, butyric, and higher 
acids of the series, as well as very small quantities of various ethers, 
acetaldehyde, furfural, acetal, and other substances influencing the bou- 
quet. 

The principal non-volatile organic substances are sugars and related 
substances, organic acids, glycerol, nitrogenous substances including traces 
of nitrates, and coloring matter {cenocyanin of red wines and quercetin of red 
wine and white and red pomace wines). 

The principal saccharine substance is invert sugar. Pentoses (chiefly 
arabinose), methylpentoses (chiefly rhamnose), inosite, and mannite occur 
in small amounts, the last named found only in unsound wines. 

The fixed acids derived from the fruit are (i) tartaric acid, the most 
abundant, existing as the free acid and as acid salts, (2) malic acid, next 
to tartaric in abundance, exists largely as the free acid which in the fresh 
juice exceeds the free tartaric acid but is largely destroyed during fer- 
mentation, and (3) citric acid, occurring only in small amounts. Traces of 
salicylic acid and probably of oxalic acid are also present in grape juice 
and wine. Tannic acid (tannin), the astringent principle of wines, notably 
the red varieties, may also be grouped with the acids derived from the fruit. 
The fixed acids formed during fermentation are lactic and succinic. The 
acidity as determined by titration does not represent accurately the sourness 
to the taste. This is shown by the hydrogen ion concentration. 

The ash constituents of chief diagnostic importance are phosphoric 
acid (reduced by dilution), potassium sulphate (increased by plastering), 
and sodium chlorate (increased by use of salt as a clarifier and preservative). 
Manganese is a normal constituent of wines. Traces of boric acid occur in 
normal wines. Arsenic and copper, derived from spraying solutions, are 
present in only infinitesimal quantities. 

Composition of Wines. — Averages of analyses of typical European wines 
as compiled by Konig are given in the table on page 717. A summary of 
analyses of California wines compiled by Bigelow appear in page 718. 

Standards. — The U. S. Standards follow : Wine is the product made 
by the normal alcoholic fermentation of the juice of sound, ripe grapes, 
and the usual cellar treatment, and contains not less than 7 nor more 
than 16 per cent of alcohol, by volume, and, in 100 cc. (20° C.) ; not more 
than 0.1 gram of sodium chloride nor more than 0.2 gram of potassium 



ALCOHOLIC BEVERAGES. 



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FOOD INSPECTION AND ANALYSIS. 



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ALCOHOLIC BEVERAGES. 719 

sulphate; and for red wine not more than 0.14 gram, and for white wine 
not more than 0.12 gram of volatile acids produced by fermentation and 
calculated as acetic acid. Red wine is wine containing the red coloring 
matter of the skins of grape. White wine is wine made from white grapes 
or the expressed fresh juice of other grapes. 

Dry wine is wine in which the fermentation of the sugars is practically- 
complete, and which contains, in 100 cc. (20° C), less than i gram of 
sugars, and for dry red wine not less than 0.16 gram of grape ash and 
not less than 1.6 grams of sugar- free grape solids, and for dry white wine 
not less than 0.13 gram of grape ash and not less than 1.4 grams of sugar- 
free grape solids. 

Fortlfiel dry wine is dry wine to which brandy has been added, but 
which conforms in all other particulars to the standard of dry wine. 

Sweet wine is wine in which the alcoholic fermentation has been 
arrested, and which contains, in 100 cc. (20° C), not less than 
I gram of sugars, and for sweet red wine not less than 0.16 gram of 
grape ash, and for sweet white wine not less than 0.13 gram of 
grape ash. 

Fortified sweet wine is sw^eet wine to which wine spirits have been 
added. By act of Congress, " sweet wine " used for making fortified 
sweet wine and " wine spirits " used for such fortification are defined 
as follows (sec. 43, Act. of October i, 1890, 26 Stat. 567, as amended 
by section 68, Act of August 27, 1894, 28 Stat. 509, and further 
amended by Act of Congress, approved June 7, 1906) : " That the 
wine spirits mentioned in section 42 of this act is the product resulting 
from the distillation of fermented grape juice to which water may have 
been added, prior to, during, or after fermentation, for the sole purpose 
of facilitating the fermentation, and economical distillation thereof, and 
shall be held to include the products from grapes or their residues, com- 
monly known as grape brandy; and the pure sweet wine, which may 
be fortified free of tax, as provided in said section, is fermented grape 
juice only, and shall contain no other substance whatever introduced 
before, at the time of, or after fermentation, except as herein expressly 
provided; and such sweet wine shall contain not less than 4 per cent 
of saccharine matter, which saccharine strength may be determined 
by testing with Balling's saccharometer or must scale, such sweet wine, 
after the evaporation of the spirits contained therein, and restoring the 
sample tested to original volume by addition of water: Provided, That 
the addition of pure boiled or condensed grape must, or pure crystallized 



720 FOOD INSPECTION AND ANALYSIS. 

cane or beet sugar, or pure anhydrous sugar to the pure grape juice 
aforesaid, or the fermented product of such grape juice prior to the 
fortiiication provided by this act, for the sole purpose of perfecting 
sweet wine according to commercial standard, or the addition of water 
in such quantities only as may be necessary in the mechanical operation 
of grape conveyors, crushers, and pipes leading to fermenting tanks, 
shall not be excluded by the definition of pure sweet wine aforesaid: 
Provided, however, That the cane or beet sugar, or pure anhydrous sugar, 
or water, so used shall not in either case be in excess of io% of the 
weight of the wine to be fortified under this act: And provided further, 
That the addition of water herein authorized shall be under such regula- 
tions and limitations as the Commissioner of Internal Revenue, with 
the approval of the Secretary of the Treasury, may from time to time 
prescribe; but in no case shall such wines to which water has been 
added be eligible for fortification under the provisions of this act where 
the same, after fermentation and before fortification, have an alcoholic 
strength of less than 5% of their volume." 

Sparkling wine is wine in which the after part of the fermentation is 
completed in the bottle, the sediment being disgorged and its place 
supplied by wine or sugar liquor, and which contains in 100 cc. (20° C), 
not less than 0.12 gram of grape ash. 

Modified wine, ameliorated wine, corrected wine, is the product made 
by the alcoholic fermentation, with the usual cellar treatment, of a 
mixture of the juice of sound, ripe grapes with sugai (sucrose), or a 
syrup containing not less than 65% of sugar (sucrose), and in quantity 
not more than enough to raise the alcoholic strength after fermentation, 
to 11% by volume. 

Raisin wine is the product made by the alcoholic fermentation of 
an infusion of dried or evaporated grapes, or of a mixture of such 
infusion, or of raisins with grape juice. 

Adulteration of Wine. — Beverages purporting to be wine are 
sometimes found on sale that are entirely spurious, in that they con- 
tain little if any fermented grape juice. Brannt gives recipes for the 
manufacture of sucii artificial products employing the following ingredients : 
apple juice, sugar syrup, rectified spirits, crushed raisins, cream of tartar, 
bilberry, elderberry, and black currant juice, acetic ether, elderberry 
flowers, and oil of bitter almonds. After fermentation the imitation wines 
are clarified with isinglass. 



ALCOHOLIC BEVERAGES. 721 

If the imitation is largely cider the tartaric acid will be low and the ash 
will give a potash instead of sodium flame. 

Wines are most frequently adulterated by " plastering," by the addi- 
tion of excessive amounts of sugar or glucose, by watering, by fraudulent 
fortification with alcohol, by the admixture of raisin wine or imitation 
wine made from pomace, by the addition of glycerin, by flavoring with 
ethers, saccharin, etc., by artificial coloring, by the addition of preserva- 
tives, and by the addition of citric or tartaric acid. 

Plastering. — By this term is understood the addition of gypsum or 
plaster of Paris to the must before fermentation, a practice in vogue in parts 
of France, Italy, and Spain. The reaction which takes place with the potas- 
sium bitartrate present in the wine is, according to Chancel, as follows : 
2KHC4H4O6 + CaS04 = CaC4H406 + H2C4H4O6 + K2SO4. 

Potassium Calcium Calcium Tartaric Potassium 

bitartrate sulphate tartrate acid sulphate 

Various advantages are said to result from this practice. The wine 
is clarified by the precipitation of the calcium tartrate, which mechan- 
ically carries down with it many impurities, the color of the wine is 
improved, since the solubility of the coloring principle present in the 
skins is incr'^ased, the fermentation is rendered more rapid and complete, 
and the keeping qualities are enhanced. Plastering of dry wines is per- 
mitted both by German and French law, provided not more than 2 grams 
of potassium sulphate per liter remains in the wine. Larger amounts 
are allowed in sweet wines (sherry, etc.). According to Blarez the limit 
for new natural wine is 0.6 gram and for old, i.o gram. 

Deplastering by means of chloride or tartrate of barium or strontium 
is also practiced. 

Addition of Cane Sugar. — During some seasons the must is deficient 
in sugar but contains an excess of acid. To bring the yield of alcohol 
up to normal the addition of sucrose is permitted in France and of sucrose, 
invert sugar and commercially pure dextrose in Germany. This practice 
is known as " chaptahzing." The addition of pure calcium carbonate to 
correct the acidity is also permitted. 

The use of commercial glucose in wine is not regarded with favor, 
since it contains more or less unfermentable matter, and introduces dextrin 
and various mineral salts into the wine. 

Invert sugar is the only sugar that should be present in natural 
wine. In normal fermentation the dextrose is more quickly destroyed 



722 FOOD INSPECTION AND ANALYSIS. 

than the levulose, hence the polarization of pure wine is always left- 
handed unless all the sugar has been fermented, in which case the 
reading should be zero. 

Bigelow found in his investigation of California wines that seventy- 
five samples of red types polarized from —0.5 to —2.1, upward of eighty 
of white types from — o.i to —3.5 (excepting four, evidently abnormal, 
showing o to +1) and thirteen of the port type from —14.7 to —27.1. 

A sharp, right-handed polarization would indicate the presence of 
either commercial glucose, dextrose or cane sugar. After inversion, if 
the reading is still right-handed, glucose or dextrose is apparent, while 
if inversion changes the reading from right to left, cane sugar has undoubt- 
edly been added. By application of Clerget's formula the amount of cane 
sugar can be estimated. 

The Watering of Wine. — Gall introduced a system of correcting must 
for an excess of acid as well as a deficiency of sweetness by adding water 
together with sugar. The German wine law of 1901 permitted "gallizing" 
if not more than 259^ of water was added and the wine did not contain 
less of the other ingredients than the average of natural wines of the 
same class. The following minimum limits in grams per ico cc. were 
adopted for gallized white and red wines: total extract, white 1.6, red 
1.7; total extract minus fixed acids, white i.i, red 13; total extract less 
total acids, white i.o, red 1.2; ash., white 0.13, red 0.16. 

The law of 1909 permits only 2oC^' of added water and requires that 
the modified must conform to the natural product of grapes of the same 
kind and region during good years. 

In France watering in any degree is not permitted. Gauticr ' a large 
number of analyses of unwatered wines found that the sum ot tlie per 
cent by volume of alcohol and the total acidity expressed in grants of 
sulphuric acid per liter varied within very narrow limits, rarely being 
below 13 or above 17. In applying this rule to plastered or soured wines 
the following preliminary corrections should be made: (i) if the potassium 
sulphate exceeds i gram per liter (plastered wine) multiply the excess by 
0.2 and deduct from the total acids; (2) if the volatile acids exceed i (soured 
wine) multiply the excess by o.i and add the product to the alcohol, also 
add I to the fixed acids to obtain the total acids. 

This rules according to Pratolongo * applies not only to all natural 
Italian wines but also to other wines. 

* Staz. sper. agr. ital., 50, 1917, p. 315. 



ALCOHOLIC BEVERAGES. 723 

Halphen * adds 0.70 to the fixed acid (expressed in grams of sulphuric 
acid per liter) and divides by the percentage of alcohol by volume. This 
ratio is highest in wines containing the lowest percentages of alcohol, as 
shown by the curves in Halphen's chart (Plate XLI). If the percentage 
of alcohol corresponding to the ratio found in a given sample is consider- 
erably greater than that obtained in the actual analysis, watering is indi- 
cated. 

Issoglio t concluded that this ratio is applicable to Italian wines, but 
Scurti and Rolando J found that 25% of water would escape detection, 
while Pratolongo, on the other hand, found that it would exclude one- 
fifth of the natural wines. 

Roos § lays stress on the ratio of the sum of the fixed acid and per- 
centage of alcohol by volume (C) to the quotient obtained by dividing the 
percentage of alcohol by volume by the percentage of extract (B). This 

ratio (-g j should not be less than 3.2 (or in extreme cases 3.0) for red 

wines or less than 2.4 for white wines. 

Blarez 1 1 employs a more complicated scheme of distinguishing natural 
from watered wines. 

Ash ^ regards California red and white wines as suspicious when they 
contain less than 2.3 and 1.6% of sugar- free solids and at the same time 
less than 16 and 15% of alcohol plus acids respectively. The same 
author concludes that a large amount of free tartaric acid in proportion 
to potassium bitartrate coupled with low sugar-free solids indicates acidi- 
fication with citric or tartaric acid as well as dilution. 

The presence of nitrates in wines has been regarded as evidence of 
watering, but Tillman,** and also Paris and Marsaglia,tt find this test 
valueless, as nitrates occur in natural wines. 

The Fortification of Wine. — The addition of alcohol to sweet wine 
such as sherry and port is recognized as an essential step in the process 
of manufacture, and in Germany the use of 1% by vol. in dry wines is also 



* Ann. chim. anal., 12, 1907, pp. 129, 196. 

t Ind. chim., 14, p. 23. 

t Ann. chim. appl., 8, 191 7, p. 47. 

§ Ann. fals. 4, 1911, p. 361. 

II Vin et Spirituex, etc., Paris, 1908. 

1 8th Int. Cong. App. Chem., 18, 191 2, p. 17. 

**Zeits. Unters, Nahr. Genussm., 22, 1911, p. 201. 

tt Staz. sperim. agrar. ital., 11, 1098, p. 123. 



724 FOOD INSPECTION AND ANALYSIS. 

allowed. When, however, alcohol is added to imitation or stretched wines 
such an addition is distinctly an adulteration. 

A committee appointed in France to devise means of detecting added 
alcohol established the rule that the grams of alcohol per loo cc. divided 
by the grams of extract should not exceed 4.5 for red wines or 6.5 for 
white wines. In the case of plastered wines, or wines having added 
sugar, it is necessary to deduct from the total extract the weight of the 
reducing sugar and of the potassium sulphate (less i gram for each of 
these substances), the reduced extract thus obtained being used in calcula- 
ing the ratio. 

In Germany the glycerol-alcohol ratio expressed in grams per 100 
cc. is also used in detecting added alcohol, the accepted limits being 7 : 100 
and 14 : 100. Both limits, however, should be extended, as German wines 
often have a ratio as high as 6 : 100 and American wines still higher, and 
19 : 100 is on record for genuine European wines. 

"Pomace Wine." — This term is applied to imitation wines prepared 
from the marc of grapes with the addition of sugar, water, and often 
tartaric or citric acid. It is not strictly a wine, and that term according 
to U. S. rulings is regarded as a misbranding even if modified by the word 
pomace. The product although not lacking in alcohol is naturally deficient 
in other characteristic constituents of true wine except, perchance, these 
are reinforced by skillful sophistication. 

EofE * has made exhaustive analyses of pomace wines from which he 
concludes that its presence in wine is usually indicated if the results per 
100 cc. are below the following : Nitrogen 10 mg. (below 5 mg. almost cer- 
tain proof), total tartaric acid 20 eg. (unfortified wine 10 eg.), fixed tartaric 
acid 50 eg., non-sugar extract 1.5 grams for white and 2.0 grams for red 
wines, and pentosans 50 mg. for white and 100 mg. for red wines. 
Pomace wine is also indicated if the ash exceeds 20 eg. (white dry wines), 
if the alkalinity of the water soluble ash is below 8 cc. N/io hydrochloric 
acid per 100 cc, or if the amount of phosphoric acid in the ash is below 
10%. Natural wines seldom contain over 5 mg. of chlorine in 100 cc; 
if it exceeds 10 mg. the presence of ammonium chloride or corn sugar solu- 
tion may be suspected. 

Piquette is prepared in France from second pressings obtained after 
soaking the marc in water. It is in a sense a diluted wine. 



* Jour. Ind. Eng. Chem., 8, 1916, p. 723. 



I 



ALCOHOLIC BEVERAGES. 725 

Raisin Wine is defined on page 720. Its detection by chemical analysis 
is often more difficult than by organoleptic test. 

The Addition of Glycerol to increase the extract, known as scheeliz- 
ing, is indicated by a high glycerol-alcohol ratio. The German com- 
mission on wine statistics decided that the presence of over 0.5 gram of 
glycerol per 100 cc, is proof of addition of this substance provided: 
(i) the extract minus fixed acids is more than two-thirds glycerol or 
(2) with a glycerol-alcohol ratio of more than 10 : 100 the total extract 
is less than 1.8 grams per 100 cc. or the total extract minus the glycerol 
is less than i gram. 

The Coloring of Wine involves the use of both vegetable and coal- 
tar dyes and is considered on pages 736-737. 

The Addition of Preservatives other than sulphur compounds is pro- 
hibited in most countries and the amount of sulphur dioxide is limited. 
Sauternes are commonly sulphured. 

Hexamethylenetetraamine (urotropin) is used for concealing the pres- 
ence of sulphur dioxide used as a preservative. On distillation with acid 
the wine thus treated yields a distillate containing formaldehyde. 

Alum is sometimes employed to clarify and to improve the color and 
keeping qualities of wine. French and German laws prohibit its use. 

Common Salt also serves as a clarifier and preservative. While normal 
wines contain only traces of chlorine, under certain conditions the quantity 
is considerable, hence the following rather generous limits expressed in 
grams per 100 cc: Germany 0.05, France o.io, Spain 0.20. 

Fruit Wines other than Grape. — Wines mostly of domestic manufac- 
ture are sometimes made from small fruits, such as raspberries, straw- 
berries, blackberries, gooseberries, elderberries, and currants, as well as 
from cherries, plums, and apricots. Wines made from most of these 
fruirs readily undergo acetic fermentation unless antiseptics are added, 
or unless extreme care is taken in their manufacture and keeping. Most 
of the sour fruits require a liberal admixture of sugar to produce an accept- 
able wine. 

The following analysis of currant wine is due to Fresenius : 

Alcohol 10.01% 

Free acid o-79% 

Sugar 11-94% 

Water 77 . 26% 



726 FOOD INSPECTION AND ANALYSIS. 

METHODS OF ANALYSIS OF WINE AND CIDER. 

For determination of specific gravity, alcohol, extract (by direct method), 
and ash, see pages 686-706. 

Calculation of the Extract in Wine. — Attention has already been called 
to the difficulty in accurately determining the extract of sweet wines 
gravimetrically by evaporation. An approximate determination of the 
extract may be obtained by calculation from the specific gravity of the 
dealcoholized liquor, or one may use for this purpose the tables compiled 
by Windisch, and based on experiments made on drying wine in vacuo 
at 75° C. In wines high in sugar, with more than 6% of extract, this 
method is far more accurate than drying at 100°, and is to be recommended. 

Evaporate a measured portion of the wine on the water-bath to one- 
fourth its volume, and dilute with water to exactly the volume measured. 
Determine the specific gravity of this dealcoholized liquid at 15.6°, and 
from the table on pages 727-729 ascertain the extract corresponding. 

Determination of Total Acidity.— Carbonated beverages are first 
freed from carbon dioxide by agitation as described on page 687, after 
which 25 cc. of the sample are heated just to the boiling-point and titrated 
with tenth-normal sodium hydroxide, using in the case of white wine 
neutral litmus solution as an indicator. With red wine delicate litmus 
paper should be used. Total acidity is usually expressed, in the case 
of cider as malic, and of wine as tartaric acid. Each cubic centimeter 
of tenth-normal alkali corresponds to 0.0067 gram malic, or 0.0075 gram 
tartaric acid. Some chemists express total acidity in terms of sulphuric 
acid, each cubic centimeter of tenth-normal alkali being equivalent to 
0.0049 gram of sulphuric acid. 

Volatile Acids in all liquors are usually expressed as acetic, although 
traces of propionic and other volatile acids may be present. 50 cc. of 
the cider or wine and a little tannic acid are transferred to a distilling- 
flask, Fig. 115, the stopper of which is provided with two tubes, one of 
which connects with the condenser, while the other, arranged to reach 
nearly to the bottom of the distilling-flask, communicates with a second 
flask which contains about 300 cc. of water. The contents of both flasks 
are brought to boiling, after which the flame under the distilling flask 
is lowered, and steam from the water-flask is passed through the wine 
till about 200 cc. of distillate have collected in the receiving-flask. 
Titrate this with tenth-normal sodium hydroxide, using phenolphthalein 
as an indicator. Each cubic centimeter of tenth-normal alkali is equiv- 
alent to 0.006 gram acetic acid. 



ALCOHOLIC BEVERAGES. 



727 



EXTRACT IN WINE. 
[According to Windisch.] 



Specific 
Gravity. 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


I . oooo 


.00 


I .0065 


1.68 


I .0130 


3-36 


1.0195 


5.04 


I .0260 1 


6.72 


1-0325 


8.40 


1 .0001 


0.03 


I .0066 


1.70 


1.0131 


3.38 


I .0196 


5.06 


I .0261 


6.75 


1.0326 


8.43 


I . 0002 


o.c; 


I .0067 


1.73 


r .0132 


3-41 


I .0197 


5 09 


I .0262 


6.77 


1.0327 


8.46 


1 .0003 


0.08 


I . 0068 


1.76 


I. 0133 


3.43 


I .0198 


5-II 


I .0263 


6.80 


1.0328 


8.48 


I .0004 


0. 10 


I .0069 


1.78 


I. 0134 


3.46 


I .0199 


S-14 


1 .0264 


6.82 


1.0329 


8.51 


I .0005 


0.13 


1 .0070 


1. 81 


I. 0135 


3.49 


I .0200 


5-17 


I .0265 


6.85 


1.0330 


8.53 


I .0006 


0.15 


1 .0071 


1.83 


I .0136 


3-51 


I .0201 


5-19 


I .0266 


6.88 


I. 0331 


8.56 


I .0007 


0.18 


I .0072 


1.86 


I. 0137 


3-54 


I .0202 


5-22 


I .0267 


6.90 


1.0333 


8.59 


1 .0008 


0. 20 


I .0073 


1.88 


1 .0138 


3.56 


I .0203 


5-25 


1.0268 


6.93 


1.0333 


8.6i 


I .0009 


0.23 


1 .0074 


1. 91 


I. 0139 


3.59 


I .0204 


5.27 


I .0269 


6.95 


I -0334 


8.64 


I .0010 


0. 26 


1.0075 


1.94 


I .0140 


3.62 


I. 020s 


5.30 


I .0270 


6.98 


1-0335 


8.66 
8.69 
8.72 

8-74 
8-77 


1 .001 1 


C.2« 


I .0076 


1 .96 


I .0141 


3.64 


I .0206 


5. 32 


I .0271 


7.01 


1-0336 


I .0012 


0.31 


1.0077 


1.99 


I .0142 


3.67 


I .0207 


5-35 


I .0272 


7.°3 


1-0337 


I .0013 


0.34 


I .0078 


2.01 


I. 0143 


3-69 


I .0208 


5.38 


1.0273 


7 .06 


1-0338 


I. 0014 


0.36 


1.0079 


2.04 


I .0144 


3.72 


I .0209 


5-4° 


1.0274 


7.08 


1-0339 


l.oois 


0.39 


I . 0080 


2.07 


1.014s 


3.75 


I .0210 


S-43 


1.0275 


7. II 


1.0340 


8-79 
8.82 
8.85 


I .0016 


.41 


I .0081 


2 .09 


I .0146 


3-77 


I .0211 


S.45 


I .0276 


7-13 


I. 0341 


I .0017 


0.44 


I .0082 


2.12 


I .0147 


3-80 


I .021 2 


5.48 


1.0277 


7-16 


1-0342 


1 .0018 


0. 46 


I .0083 


2.14 


I . 0148 


3.82 


I .0213 


5-51 


1 .0278 . 


7.19 


1-0343 


8.87 
8.90 


I .0019 


0.49 


I .0084 


2.17 


I .0149 


3.85 


I .0214 


5-53 


I. 0279 


7.21 


1-0344 


I .0020 


0.52 


1.0085 


2 . 19 


1 .0150 


3.87 


I .0215 


5.56 


I .0280 


7.24 


I -034s 


8.92 


I .0021 


0. 54 


I .0086 


2.22 


1.0151 


3 90 


I .0216 


5.58 


I .0281 


7 . 26 


I -0346 


8.95 


I .0022 


0.57 


I .0087 


2.25 


I .0152 


3.93 


1 .0217 


5. 61 


I .0282 


7.29 


1-0347 


8-97 


I .0023 


O.S9 


1.0088 


2.27 


I.OIS3 


3-95 


I .0218 


5-64 


I .0283 


7-32 


I -0348 


9 . 00 


1 .0024 


0. 62 


I .0089 


2.30 


I .0154 


3.98 


I .0219 


5.66 


I .0284 


7-34 


1-0349 


9-03 


1.0025 


0.64 


I .0090 


2.32 


I. 0155 


4.00 


I .O220 


5.69 


I .0285 


7-37 


1-0350 


9-oS 


I .0026 


0. 67 


I .0091 


2.3S 


1 . 1 5 6 


403 


I .0220 


5-71 


1.0286 


7-39 


1-0351 


9.08 


I .0027 


0.69 


I .0092 


2.38 


I. 0157 


4.06 


I .0222 


5-74 


I .0287 


7-42 


I -0352 


9. 10 


1 .0028 


0.72 


1 .0093 


2 .40 


I. 0158 


4.08 


I .0223 


5-77 


1.0288 


7-45 


1-0353 


9.13 
9. 16 


I .0029 


0.7s 


I .0094 


2-43 


I. 0159 


4. II 


I .0224 


5-79 


I .0289 


7-47 


1-0354 


I .0030 


0.77 


1.0095 


2.45 


I . 0160 


4-13 


I .0225 


5.82 


I .0290 


7-50 


I-03SS 


9.18 


I .0031 


0.80 


I .0096 


2.48 


I .0161 


4. 16 


I .0226 


5.84 


I .0291 


7.52 


1-0356 


9.21 


I .0032 


0.82 


I .0097 


2. 50 


I .0162 


4.19 


I .0227 


5. 87 


I .0292 


7-55 


1-0357 


9-23 


1.0033 


0.85 


I .0098 


2.53 


I .0163 


4.21 


I .0228 


5.89 


i.0293 


7-58 


1.0358 


9. 26 


1.0034 


0.87 


1.0099 


2.56 


I .0164 


4.24 


I .0229 


5-92 


I .0294 


7 .60 


I. 0359 


9.29 


I .0035 


0.90 


I .0100 


2.58 


1.016s 


4. 26 


I .0230 


5-94 


1.0295 


7-63 


I .0360 


9-31 


I .0036 


0.93 


I .0101 


2.61 


I .0166 


4.29 


I .0231 


5-97 


I .0296 


7-65 


I .0361 


9-34 


1.0037 


0.95 


I .0102 


2.63 


I .0167 


4-31 


I .0232 


6.00 


1.0297 


7.68 


1.0362 


9-36 


I .0038 


0.98 


I .0103 


2.66 


I. 0168 


4-34 


1.0233 


6.02 


I .0298 


7.70 


I -0363 


9-39 


I .0039 


1 .00 


I .0104 


2.69 


I .0169 


4-37 


1.0234 


6.05 


I .0299 


7-73 


1 .0364 


9-42 


I. 0040 


I .03 


I .0105 


2.71 


I .0170 


4-39 


1.0235 


6.07 


I .0300 


7.76 


1.0365 


9-44 


I ,0041 


I -OS 


I .0106 


2.74 


I .0171 


4.42 


1.0236 


6. 10 


1.0301 


7.78 


I .0366 


9-47 


I .0042 


I .08 


I .0107 


2. 76 


I .0172 


4-44 


1.0237 


6.12 


I .0302 


7.81 


1.0367 


9.49 


1.0043 


I .11 


I .0108 


2.79 


I. 0173 


4-47 


I .0238 


6.15 


1-0303 


7.83 


1.0368 


9-5a 


1.0044 


I.I3 


I .0109 


2.82 


I. 0174 


4.50 


I .0239 


6.18 


1.0304 


7 .86 


I 0369 


9-55 


1.004s 


1. 16 


1 .0110 


2.84 


I. 0175 


4-52 


I .0240 


6. 20 


1.0305 


7.89 


. 1-0370 


9-57 


I .0046 


1. 18 


1 .0111 


2.87 


1 .0176 


4.5s 


I .0241 


6.23 


I .0306 


7.91 


1-0371 


9.60 
9.62 


I .0047 


1 . 21 


1 .0112 


2.89 


I. 0177 


4-57 


I .0242 


6.25 


1.0307 


7-94 


1.0372 


I .0048 


1 .24 


1 .0113 


2 .92 


I .0178 


4.60 


1.0243 


6.28 


1.0308 


7-97 


1-0373 


9-65 
9-68 


1.0049 


1.26 


I .0114 


2.94 


I. 0179 


4.63 


I .0244 


6.31 


I .0309 


7-99 


1-0374 


1 .0050 


1 . 29 


I .0115 


2.97 


I .0180 


4.65 


1.0245 


6.33 


I .0310 


8.02 


1.037s 


9-70 


1 .0051 


1 .32 


I .01 16 


3- 00 


I .oi8i 


4.68 


I .0246 


6.36 


I .0311 


8.04 


1-0376 


9-73 


1 .0052 


1.34 


I .0117 


3-02 


I .0182 


4.70 


I .0247 


6.38 


I .0312 


8.07 


1.0377 


9.75 


1 .0053 


1.37 


I .0118 


3-05 


I .01S3 


4-73 


I .0248 


6.41 


1-0313 


8.09 


1-0378 


9-73 


1.0054 


1.39 


I .01 19 


3-07 


I .0184 


4.7s 


I .0249 


6.44 


I. 0314 


8-12 


1-0379 


9-80 


1 .0055 


1 .42 


I .01 20 


3.IO 


I .0185 


4.78 


I .0250 


6.46 


1.0315 


8.14 


I .0380 


9-83 


1 .0056 


I -45 


I .0121 


3-12 


1. 0186 


4.81 


I .0251 


6.49 


I .0316 


8.17 


1 .0381 


9-86 


1.0057 


I .47 


I .0122 


3-15 


I .0187 


4.83 


1.0252 


6.51 


1.0317 


8.20 


1.0382 


9-88 


1 .0058 


I . 50 


I .0123 


3.18 


1.018S 


4.86 


I.02S3 


6.54 


I .0318 


8.22 


1-0383 


9.91 


1 .0059 


1.52 


I .0124 


3 -20 


I .0189 


4. 88 


1.0254 


6.56 


I. 0319 


8.25 


1 -0384 


9.93 


1 .0060 


i-SS 


I .0125 


3-23 


I . 0190 


4.91 


1.0255 


6.59 


I .0320 


8.27 


1.0385 


9.96 


1 .0061 


1-57 


I . 01 26 


3-26 


I .0191 


4-94 


1 .0256 


6.62 


I .0321 


8.30 


1.0386 


9-99 


I .0062 


1 .60 


I .0127 


3.28 


I .0192 


4.96 


] .0257 


6.64 


1.0322 


8-33 


1.0387 


10 .01 


I .0063 


1.63 


I .0128 


3-31 


I.OI93 


4 09 


1 . 2 5 cS 


6.67 


1.0323 


8-35 


1.0388 


10.04 


1.0064 


1.6s 


I .0129 


3-33 


I .0194 

1 


S-Ol 


1.0259 


6. 70 


1-0324 


8.38 


1.0389 


10.06 



728 



FOOD INSPECTION AND ANALYSIS. 



EXTRACT IN \YmE— {Continued). 



Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


I .0390 


10.09 


I-045S 


11.78 


1.0520 


13.47 


1.0585 


i5-i6 


I .0650 


16.86 


1.0715 


18.56 


I .0391 


10. 1 1 
10. 14 


1-0456 


II. 81 


1.0521 


13.49 


1.0586 


15.19 


I. 0651 


16.88 


1 .0716 


18.58 


I 0392 


I.0457 


11.83 


1 .0522 


13-52 


1.0587 


15.22 


I .0652 


16.91 


1.0717 


18.61 


1.0393 


10. 17 


1.0458 


11.86 


1.0523 


13. 55 


1.0588 


15-24 


1.0653 


16.94 


I .0718 


18.63 


1.0394 


10.19 


I.04S9 


11.88 


1.0524 


13-57 


1.0589 


15.27 


1.0654 


16. 96 


I. 0719 


18.66 


1.0395 


10. 22 


I .0460 


11.91 


1-0525 


I 3 . 60 


1.0590 


15.29 


1.0655 


16.99 


I .0720 


1S.69 


I .0396 


10. 25 I I. 0461 


11.94 


I .0526 


13.62 


I. 0591 


15-32 


I .0656 


17.01 


1 .0721 


18.71 


1.0397 


10.27 


I . 0462 


II .96 


1-0527 


13-65 


1.0592 


15-35 


1.0657 


17.04 


I .0722 


18.74 


I .0398 


10.30 


1 .0463 


11.99 


I .0528 


13-68 


1.0593 


15-37 


1.0658 


17-07 


1.0723 


18.76 


1.0399 


10. 32 


I .0464 


12.01 


1.0529 


13-70 


1.0594 


15-40 


I .0659 


17.09 


1.0724 


18.79 


1 .0400 


10.35 


1.046s 


12.04 


1.0530 


13-73 


I-0595 


15-42 


I .0660 


17 12 


I .0725 


18.82 


I .0401 


10.37 


I .0466 


1 2 .06 


1.0531 


13-75 


1.0596 


15-45 


I .0661 


17.14 


I .0726 


18.84 


I . 0402 


10.40 


1.0467 


1 2 .09 


1-0532 


13-78 


1-0597 


iS-48 


I . 0662 


17-17 


1.0727 


18.87 


I .0403 


10.43 


I .0468 


12.12 


1-0533 


13.81 


1-059S 


15-SO 


I .0663 


17 . 20 


I .0728 


18.90 


I .0404 


10.4s 


I .0469 


12.14 


1-0534 


13-83 


1.0599 


15-53 


I .0664 


17.22 


1.0729 


18.92 


I. 040s 


10.48 


1 .0470 


12.17 


1-053S 


13-86 


I .0600 


15. 55 


1.0665 


17-25 


I .0730 


18.95 


I .0406 


10.51 


I .0471 


12.19 


1-0536 


13-89 


I .0601 


iS-58 


I .0666 


17.27 


1-0731 


18.97 


I .0407 


10.53 


1.0472 


12.22 


1-0537 


13-91 


I .0602 


15.61 


I .0667 


17.30 


1-0732 


19.00 


I .0408 


10. 56 [( 1 .0473 


12.25 


1.0538 


13-94 


I .0603 


15-63 


1.0668 


17.33 


1.0733 


19.03 


I .0409 


10.58 


1 I .0474 


12. 27 


I.0539 


13-96 


I . 0604 


15-66 


I .0669 


17-35 


1.0734 


19-05 


I .0410 


10. 61 


1.047s 


12.30 


1 .0540 


13-99 


I .0605 


15. 68 


1 .0670 


17-38 


1.0735 


19-08 


I .0411 


10.63 


1.0476 


12.32 


I-0541 


14.01 


I .0606 


15-71 


I .0671 


17.41 


1.0736 


19. 10 


I .041 2 


10. 66 


] 1.0477 


12-35 


1-0542 


14.04 


I .0607 


15-74 


1 .0672 


.17-43 


1.0737 


19-13 


I .0413 


10.69 


1.0478 


12.38 


1-0543 


14-07 


I . 0608 


15-76 


1.0673 


17.46 


1.0738 


19- 16 


I .0414 


10. 71 


i 1.0479 


12.40 


1-0544 


14.09 


1 .0609 


15-79 


I .0674 


17-48 


1.0739 


19. iS 


1.041S 


10.74 


I .0480 


12.43 


I.054S 


14.12 


I .0610 


15.81 


1.0675 


17-51 


I .0740 


19.21 


1 .0416 


10. 76 


I .0481 


12-45 


I .0546 


14.14 


I . 0611 


iS-84 


I .0676 


17-54 


1-0741 


19-2. 


1.0417 


10.79 


I .0482 


12.48 


1.0547 


14.17 


I .0612 


JS-87 


1.0677 


17-56 


1.0742 


19. 2C 


1 .0418 


10.82 


I I .0483 


12.51 


1 .0548 


14. 20 


I. 0613 


15-89 


1.0678 


17-59 


1.0743 


19-2C 


I .0419 


10.84 


1.0484 


12.53 


1.0549 


14. 22 


I .0614 


15-92 


I .0679 


17.62 


1.0744 


19-3] 


I .0420 


10.87 


1.048s 


12. s6 


1.0550 


14-25 


I .0615 


15-94 


1 .0680 


17.64 


1.0745 


19-31 


I .0421 


10 . 90 


I .0486 


12.58 


1.0551 


14.28 


I .0616 


15-97 


I. 0681 


17.67 


I . 0746 


19-3- 


I .0422 


10.92 


I .0487 


12.61 


1.0552 


14.30 


I .0617 


16. 00 


1.0682 


17-69 


1.0747 


19-3? 


I .0423 


10.9s 


1.0488 


12.64 


1.0553 


14-33 


I. 0618 


16.02 


1.0683 


17.72 


I .0748 


19.4: 


I .0424 


10.97 


I .0489 


12.66 


I.05S4 


14-35 


I .0619 


16.05 


I .0684 


17.75 


1.0749 


19-41 


1.0425 


II .00 


I .0490 


12 . 69 


1.0555 


14-38 


I .0620 


16.07 


1.0685 


17.77 


1-0750 


19.4- 


I .0426 


II .03 


I .0491 


12.71 


1-0556 


14.41 


I .0621 


16. 10 


1.0686 


17.80 


I. 0751 


19-5C 


I .0427 


11.05 


I .0492 


12.74 


1-0557 


14-43 


I .0622 


16. 13 


1.0687 


17.83 


1.0752 


19-52 


1 .0428 


11.08 


I -0493 


12.77 


1.0558 


14.46 


I .0623 


16.15 


1.0688 


17-85 


1-0753 


19-5! 


I .0429 


II . 10 


1.0494 


12.79 


1.0559 


14.48 


I .0624 


16.18 


I .0689 


17-88 


1-0754 


19-5^ 


1.0430 


II. 13 


I .0495 


12.82 


I .0560 


14-51 


I .0625 


16.21 


I .0690 


17.90 


1-0755 


19. 6c 


I. 0431 


II. 15 


I .0496 


12.84 


I .0561 


14-54 


I .0626 


16.23 


j I . 0691 


17-93 


1-0756 


19- 6:3 


I .0432 


II. 18 


1.0497 


12.87 


I .0562 


14.56 


1 .0627 


16.26 


I . 0692 


17-95 


1-0757 


19.65 


1 -0433 


II . 21 


I .049S 


12.90 


1.0563 


14-59 


1.0628 


16.28 


1.0693 


17-98 


1-0758 


19.68 


I -0434 


11.23 


1.0499 


12.92 


1.0564 


14.61 


I .0629 


16.31 


I .0694 


18.01 


1-0759 


19-71 


1.0435 


II . 26 


I .0500 


12.95 


1.056s 


14.64 


I .0630 


16.33 


I .0695 


18.03 


I .0760 


19-73 


I .0436 


11.28 


I .0501 


12.97 


I .0566 


14.67 


I .0631 


16.36 


I .0696 


18.06 


I .0761 


19.76 


I -0437 


II. 31 


I .0502 


13.00 


1.0567 


14-69 


1.0632 


16.39 


I .0697 


18.08 


I .0762 


19-79 


I .04.58 


11-34 


1.0503 


13.03 


1.0568 


14-72 


1.0633 


16.41 


I .0698 


18. II 


1.0763 


19.81 


1.0439 


II .36 


I .0504 


13.05 


1-0569 


14.74 


I .0634 


16.44 


I .0699 


18.14 


I .0764 


19.84 


I . 0440 


11-39 


I. 050s 


13-08 


1-0570 


14-77 


1.0635 


16.47 


I .0700 


18.16 


1.0765 


19.86 


I .0441 


II .42 


I .0506 


13-10 


1-0571 


14.80 


I .0636 


16.49 


I . 0701 


18.19 


I .0766 


I9.8g 


I .0442 


11.44 


1.0507 


13-13 


1 1.0572 


14.82 


1.0637 


16. 52 


I .0702 


18.22 


1.0767 


19.92 


I .0443 


11.47 


I . 0508 


13-16 


1.0573 


14-85 


1.0638 


16.54 


1.0703 


18.24 


1.0768 


19-94 


1.0444 


11.49 


1.0509 


13.18 


1.0574 


14.87 


1 -0639 


16.57 


I .0704 


18.27 


1 .0769 


19-97 


1.0445 


11-52 


1 .0510 


13.21 


1.0575 


14.90 


I .0640 


16.60 


1.0705 


18.30 


I .0770 


20.00 


I .0446 


11-55 


1.0511 


13.23 


1.0576 


14.93 


1 .0641 


16.62 


I .0706 


18.32 


1.0771 


20.02 


I .0447 


11-57 


1 .0512 


13-26 


1.0577 


14-95 


I .0642 


16.65 


1.0707 


18.35 


1.0772 


20.05 


I . 0448 


1 1 . 60 


1-0513 


13-29 


I .0578 


14.98 


I .0643 


16.68 


1 . 0708 


18.37 


I.0773 


20.07 


I .0449 


1 1 . 62 


1.0514 


13-31 


1-0579 


15-00 


I .0644 


16.70 


I .0709 


18.40 


1.0774 


20. 10 


I .0450 


1 1 . 65 


1-0515 


13.34 


I .0580 


15-03 


I .0645 


16.73 


I .0710 


1S.43 


I-077S 


20. 12 


I .0451 


11.68 


I -0516 


13-36 


I .0581 


15-06 


I .0646 


16.75 


I .0711 


18.45 


I .0776 


20.15 


I .0452 


1 1 . 70 


1.0517 


13-39 


1 .0582 


15-08 


I .0647 


16.78 


I .0712 


1 8. 48 


1-0777 


20.18 


I -0453 


11-73 


1-0518 


13-42 


1.0583 


15-H 


I .0648 


16.80 


1-0713 


18.50 


1.0778 


20. SO 


I. 0454 


11-75 


I. 0519 


13-44 


I .05S4 


15-14 


I .0649 


16.83 


1.0714 


1S.53 

1 


1.0779 


20. 23 



ALCOHOLIC BEVERAGES. 



729 



EXTRACT IN \NlNE—iCon/!niicd). 



Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 


Ex- 


Specific 1 Ex- 


Specific 


Ex- 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


Gravity. 


tract. 


I .0780 


20 . 26 


I .0845 


21 .96 


I .0910 


23.67 


1.097s 


25. 38 


1 . 1040 


27.09 


I. 1105 


28.81 


1 .0781 


20.28 


1.0846 


21.99 


I .ogii 


23.70 


I .0976 


25.41 


I . 1041 


27.12 


I . 1106 


28.83 


1 .0782 


20.31 


1 .0847 


22 .02 


I .091 2 


23.72 


1.0977 


25-43 


I . 1042 


27. IS 


1 . 1107 


28.86 


1.0783 


20.34 


1.0848 


22.04 


I. 0913 


23-75 


I .0978 


25.46 


1. 1 043 


27.17 


1 . 1108 


28.88 


I .0784 


20.36 


I .0849 


22.07 


I .0914 


23.77 


1.0979 


25.49 


I . 1044 


27. 20 


1 . 1 109 


28.91 


1.078s 


20.39 


1.0850 


22.09 


I. 0915 


23.80 


I .0980 


25-51 


1.104s 


27 . 22 


1 . 1 1 10 


28.94 


1.0786 


20.41 


I. 0851 


22.12 


I .0916 


23-83 


I .0981 


25.54 


I . 1046 


27.25 


1 .1111 


28.96 


1.0787 


20.44 


1.0852 


22.15 


I. 0917 


23-85 


I .0982 


25-56 


I. 1047 


27.27 


1.1112 


28.99 


1.0788 


20.47 


1.0853 


22.17 


I .0918 


23.88 


1.0983 


25.59 


I . 1048 


27.30 


I -1113 


29 . 02 


1.0789 


20.49 


1.0854 


22. 20 


I .0919 


23.91 


I .0984 


25.62 


1 . 1049 


27-33 


1 . 1 1 14 


29.04 


I .0790 


20.52 


1.085s 


22. 22 


I .0920 


23.93 


1.098s 


25.64 


1.1050 


27.35 


i.ms 


29.07 


1 .0791 


20. ss 


1.0856 


22. 25 


I .0921 


23.96 


I .0986 


25.67 


1.1051 


27.38 


1 . 1116 


29.09 


1.0792 


20. 57 


1.0857 


22.28 


I .0922 


23.99 


I .0987 


25.70 


1 . 1052 


27.41 


1.1117 


29. 13 


1-0793 


20.60 


1.0858 


22.30 


1.0923 


24.01 


I .0988 


25.72 


1.1053 


27.43 


1.1118 


29-15 


1.0794 


20.62 


I .0859 

1 


22.33 


I .0924 


24.04 


I .0989 


25.75 


1 1.1054 


27.46 


1 . 1119 


29.17 


1.079s 


20.65 


1 
I .0860 


22.36 


1.092s 


24.07 


I .0990 


25.78 


1.105s 


27.49 


I .1120 


29 . 20 


1 .0796 


20.68 


i.o86i 


22.38 


1 .0926 


24.09 


1 .0991 


25-80 


I. 1056 


27.51 


I . 1121 


29.23 


1.0797 


20. 76 


1.0862 


22 .41 


1 .0927 


24. 12 


1 .0992 


25.83 


i I. 1057 


27-54 


1.1122 


29.25 


1 .0798 


20.73 


1.0863 


22.43 


I .0928 


24.14 


1.0993 


25-85 


1. 1058 


27-57 


1.1123 


29. 28 


1.0799 


20.7s 


I .0864 


22.46 


I .0929 


24.17 


1.0994 


25.88 


I.IOS9 


27.59 


1 . 1124 


29.31 


I .oSoo 


20.78 


1.086s 


22.49 


1.0930 


24. 20 


I -0995 


25.91 


1 1 . 1060 


27 .62 


I.II2S 


29.33 


1 .0801 


20.81 


1.0866 


22.51 


I. 0931 


24. 22 


I .0996 


25.93 


1 . 1061 


27-65 


1 . 1126 


29.36 


1 .0802 


20.83 


1.0867 


22.54 


1.0932 


24-25 


1.0997 


25.96 


1 . 1062 


27.67 


I . 1127 


29.39 


1 .0803 


20.86 


1.0868 


22.57 


1.0933 


24.27 


I .0998 


25.99 


1.1063 


27.70 


1.1128 


29.41 


1 .0804 


20.89 


I .0869 


22.59 


1.0934 


24.30 


1.0999 


26.01 


j I . 1064 


27.72 


1 .1129 


29.44 


I .0805 


20.91 


I .0870 


22 . 62 


1.093s 


24.33 


1 . 1000 


26.04 


1.1065 


27-75 


1.1130 


29.47 


I .0806 


20.94 


I .0S71 


22.65 


I .0936 


24.3s 


I . lOOI 


26.06 


I . 1066 


27.78 


1.1131 


29.49 


I .0807 


20.96 


I .0872 


22.67 


1.0937 


24.38 


1 . 1002 


26.09 


1 1 . 1067 


27.80 


I. 1132 


29.52 


1.0808 


20.99 


1.0873 


22. 70 


1.0938 


24.41 


I. 1003 


26.12 


r.io68 


27.83 


I.II33 


29.54 


1 .0809 


21 .02 


I .0874 


22.72 


1.0939 


24.43 


I . 1004 


26. 14 


I . 1069 


27.86 


1.1134 


29.57 


I .0810 


21 .04 


1.087s 


22.75 


I .0940 


24.46 


1 . loos 


26. 17 


1 . 1070 


27.88 


I.II3S 


29. 60 


1 .081 1 


21 .07 


1.0876 


22.78 


I .0941 


24.49 


I . 1006 


26 . 20 


I . 1071 


27.96 


1.1136 


29. 62 


1 .0812 


21.10 


1.0877 


22.80 


1.0942 


24.51 


I . 1007 


26. 22 


I . 1072 


27.93 


1.1137 


29.65 


I. 0813 


21.12 


1.0S78 


22.83 


1.0943 


24-54 


1 . 1008 


26.25 


1.1073 


27.96 


1.1138 


29.68 


1 .0814 


21 .IS 


1 .0879 


22.86 


1.0944 


24.57 


I . 1009 


26. 27 


1 I. 1074 


27.99 


1.1139 


29.70 


I .0815 


21 . 17 


1.0880 


22.88 


1.0945 


24.59 1 


I . lOIO 


26.30 


1.107s 


28.01 


I . 1140 


29.73 


I. 0816 


21 . 20 


I. 0881 


22.91 


I .0946 


24.62 J 


I . lOII 


26.33 


1 . 1076 


28.04 


1 . 1141 


29.76 


I .081 7 


21.23 


1.0882 


22.93 


1.0947 


24.64 


1 . 1012 


26.35 


1.1077 


28.07 


1 . 1142 


29.78 


1. 08 1 8 


21.25 


1.0883 


22.96 


I .0948 


24.67 


1.1013 


26.38 


I . 1078 


28.09 


1.1143 


29.81 


I .0819 


21 .28 


1.0884 


22.99 


1.0949 


24.70 


1 . 1014 


26.41 


1.1079 


28.12 


1.1144 


29.83 


1 .0820 


21.31 


1.088s 


23.01 


1.0950 


24.72 


I . 1015 


26.43 


I . 1080 


28.1s 


1.1145 


29.86 


I .0821 


21.33 


1.0886 


23.04 


1.0951 


24.7s 


I . 1016 


26.46 


1 . 1081 


28.17 


I . 1146 


29.89 


I .0822 


21.36 


1.0887 


23.07 


1.0952 


24.78: 


I . 1017 


26.49 


1 . 1082 


28.20 


1.1147 


29.91 


1.0823 


21.38 


1.0888 


23.09 


1.0953 


24.80 


1 . 1018 


26.51 


1.10S3 


28. 22 


1 . 1148 


29.94 


1 .0824 


21 .41 , 


1.0889 


23. 12 


1.0954 


24.83 

j 


I . 1019 


26.54 


1 . 1084 


28.2s 


I .1149 


29 . 96 


1.082s 


21.44 


I .0890 


23.14 


1.0955 


24.85 


I . 1020 


26.56 


1 . 1085 


28.28 


I . 1150 


29.99 


1.0826 


21 .46 


I .0891 


23.17 


1.0956 


24.88 


1 . 1021 


26.59 


1.1086 


28.30 


1 .1151 


30.02 


I .0827 


21.49 


I .0892 


23.20 


1.0957 


24.91 


1 . 1022 


26.62 


I . 1087 


28.33 


1.1152 


30.04 


1.0828 


21.52 


I .0893 


23.22 


1.0958 


24.93 


I. 1023 


26. 64 


I. 1088 


28.36 


1.1153 


30.07 


I .0829 


21. S4 


I .0894 


23.2s 


1.0959 


24.96 


1 . 1024 


26.67 


I . 1089 


28.38 


1.1154 


30.10 


I .0830 


21.57 


I .0895 


23.28 


1 .0960 


24.99 


I . 1025 


26. 70 


I . 1090 


28.41 


i.iiSS 


30.13 


I. 0831 


21.59 


I .0896 


23.30 


I .0961 


25.01 


I . 1026 


26.72 


1 . 1091 


28.43 


I.II56 


30.15 


I .0832 


21.62 


I . 0S97 


23.33 


I .0962 


25.04 


I . 1027 


26.75 


1 . 1092 


28.46 


I.II57 


30.18 


1.0833 


21 .65 


1.0S98 


23.35 


1.0963 


25.07 


1.102S 


26.78 


I. 1093 


28.49 


1-1158 


30.21 


1.0834 


21 . 67 . 


I .0899 


23.38 


I .0964 


25.09 


I . 1029 


26.80 


1 . 1094 


28.51 


1.1159 


30.23 


1.083s 


21 . 70 


I . 0900 


23.41 


I .0965 


25.12 


I. 1030 


26.83 


1.109s 


28.54 






1.0836 


21.73 


I .0901 


23.43 


1 .0966 


25.14 


I. 1031 


26.85 


1 . 1096 


28.57 






1.0837 


21.75 


I .0902 


23.46 


I .0967 


25.17 


I. 1032 


26.88 


1.1097 


28.59 






1.0838 ^ 


21.78 


I .0903 


23.49 


1 .0968 


25 . 20 


I.I033 


26.91 


I . 1098 


28.62 






1.0839 


21.80 


1 .0904 


23.51 


I .0969 


25 . 22 


I. 1034 


26.93 


1 . 1099 


28.65 






I .0840 


21.83 


I .0905 


23.54 


I .0970 


25.25 


I .103s 


26.96 


I . 1100 


28.67 






1.0841 


21.86 


I .0906 


23.57 


I. 0971 


25.28 


I .1036 


26. 99 


1 . IIOl 


28.70 






I .0842 


21.88 


I .0907 


23.59 


I .0972 


25.30 


I. 1037 


27 .01 


1 . 1102 


28.73 






1.0843 


21 .91 


I .0908 


23.62 


1.0673 


25.33 


1.1038 


27.04 


1 .1103 


28.75 






1.0844 


21.94 

1 


I .0909 


23-65 


1.0974 


25.36 


1. 1039 


27.07 


I . 1104 


28.78 







730 



FOOD INSPECTION AND ANALYSIS. 




Fig. 114. — Apparatus for Determining Volatile Acids in Wine. 




Fig. 115. — Hor'ivct's .apparatus for .D-terniining the \'olatilc Acids in Wine. 



ALCOHOLIC BEVERAGES. 731 

Hortvet Method.^—The apparatus (Fig. 115) consists of a 300-cc. 
flask into the neck of which is fitted a 2co-cc. cylindrical fiask, with a 
steam tube, a bulb-trap leading to a condenser, and a stop-cock funnel. 
The procedure is as follows: Pour 150 cc. of recently boiled water into 
the larger flask, attach the smalLer flask by means of a section of rubber 
tubing, run in 10 cc. of wine (previously freed from carbonic acid), 
close the stop-cock and boil. In extreme cases add to the wine a small 
piece of paraffin to prevent foaming. When the water has boiled a 
moment, close the tube at the side of the larger flask and distil until 
70 cc. of distillate have passed over. Transfer to a beaker, without 
discontinuing the distillation, and titrate, using phenolphthalein as in- 
dicator. Continue the distillation until the last 10 cc. portion requires 
not more than one drop of tenth-normal alkali for neutralization. Usually 
80 or 90 cc. of distillate includes practically all of the volatile acids. Cool 
the apparatus, thus allowing the wine residue to be drawn back into the 
lower flask, rinse with boiled water, and reserve the total liquid for deter- 
mination of non-volatile acids. 

Criicss and Betloli Metliod.'\ — Shake 75 cc. of the wine with bone 
black free from carbonates, filter, and titrate 20 cc. of the decolorized 
filtrate with N/io alkali using phenolphthalein as indicator. Place 
another aliquot of 20 cc. of the decolorized wine in a 200-cc, Erlenmeyer 
flask, add 2 grams of sodium chloride, and evaporate rapidly until sodium 
chloride separates copiously and the liquid begins to spatter. Dilute with 
20 cc. of water and repeat the operation. Dilute a second time and titrate 
with N/io alkali as before. The difference between the two titrations 
multiplied by 0.03 gives the amount of volatile acids in grams per 100 cc. 

Detection of Free Tartaric Acid. — Nessler's Method. — Some pow- 
dered cream of tartar is added to a portion of the wine in a corked flask, 
which is shaken from time to time, and the liquid finally filtered. To 
the filtrate is added a little 20% potassium acetate solution. If free 
tartaric acid is present, on stirring and especially after standing for some 
time, there will be a precipitate of cream of tartar. 

Determination of Total Tartaric Acid. — Hartmann and Eoff Method.X 
— Neutralize ico cc. of the wine with N sodmm hydroxide to counteract the 
influence of free mineral acids, especially phosphoric; if more than 10 cc. 

* Jour. Ind. Eng. Chem., i, iQog, p. 31. 
t Ses. Int. Cong. Vit. Off. Rep., 1915, 263. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 162, 1913, p. 72; Jour. Assn. Off. Agric. 
Chem., 2, II, 1917, p. 182. 



732 FOOD INSPECTION AND ANALYSIS. 

are required evaporate to about loo cc. Dissolve in the solution for 
each cc. of alkali added 0.075 gram accurately weighed, powdered c.p. 
tartaric acid, dried for 2 hours at 100° C. Add 2 cc. of glacial acetic 
acid and 15 grams of potassium chloride, stir until dissolved, then add 
15 cc. of 95% alcohol, and stir vigorously until cream of tartar begins to 
precipitate. Allow to stand for at least 15 hours in an ice box, decant 
onto a Gooch crucible or Biichner funnel, and carefully wash the precipi- 
tate and filter three times with a solution of 1 5 grams of potassium chloride 
in 20 cc. of 95% alcohol and 100 cc. of water, using a total of not more 
than 20 cc. Return contents of the crucible or funnel to the beaker, 
rinsing with 50 cc. of hot water, heat to boiling, and titrate the solution 
while hot with N/io sodium hydroxide using phenolphthalein as indicator. 
Add to the number of cc, required 1.5 to correct for solubility of cream of 
tartar and multiply by 0.015 to obtain the total weight of tartaric acid 
present in the solution. Subtract from the product the weight of tartaric 
acid added, thus obtaining the total tatraric acid present in 100 cc. of 
wine. 

Determination of Cream of Tartar. — Exhaust the ash of 50 cc. of wine 
with hot water on a filter, add 25 cc. of N/io hydrochloric acid, heat 
to incipient boiling, and titrate with N/ro alkali solution, using litmus 
as indicator. Deduct from 25 cc. the number of cc. of N/io alkali em- 
ployed, and multiply the remainder by 0.0188 to obtain potassium bitar- 
trate in grams. 

Determination of Free Tartaric Acid. — Add 25 cc. of N/io hydro- 
chloric acid to the ash of 50 cc. of wine, heat to incipient boiling, and titrate 
with N/io sodium hydroxide, using litmus as indicator. Deduct the 
number of cc. of alkali employed from 25, and multiply the remainder by 
0.0075 to obtain the amount of tartaric acid necessary to combine with all 
the ash (considering it to consist entirely of potash). Deduct the figure 
so obtained from the total tartaric acid. The difference is the amount of 
free tartaric acid. 

Determination of Lactic Acid. — Moslinger Method * Modified hy Bara- 
giola and Schuppli.'\ — Distil in steam 25 cc. of the sample and 25 cc. of 
water in von der Heide's fractionating apparatus until 200 cc. have been 
collected. Transfer the residue to a small dish, add 5 cc. of 10% barium 
chloride solution and hot saturated barium hydroxide solution to neutral 



* Zeits. Unters. Nahr. Genussm., 4, 1901, p. 1123. 
t Ibid., 27, 1914, p. 841. 



ALCOHOLIC BEVERAGES. 733 

reaction, then 2 to 4 cc. in excess, and heat for ten minutes on a water- 
bath. Add hydrochloric acid until neutral to azolitmin paper, evaporate 
to 10 to 15 cc, taking care that the reaction remains neutral, transfer to a 
graduated cylinder, rinsing with water, and make up to 25 cc. Add 95% 
alcohol gradually with shaking up to 100 cc. and after standing for several 
hours again adjust the volume to 100 cc. and filter. To 75 cc. of the 
filtrate add 25 cc. of 5% sodium sulphate solution, shake, filter after stand- 
ing fifteen minutes, evaporate 75 cc. of the filtrate in platinum, and ignite 
to whiteness. Take up the ash in water, add an excess of N/io hydro- 
chloric acid, heat for five minutes on a water-bath, and titrate back with 
standard alkali using azolitmin paper, methyl orange, or phenolphthalein 
as indicator. 

To obtain the lactic acid in grams per liter multiply the corrected 
number of N/io acid by 0.64. 

Moslinger Method Modified by Roettgen."^ — Distil 50 cc. of the wine 
in a fractionating apparatus, provided with a column containing glass 
beads, until 200 cc. have passed over. To the residue add 5 cc. of 20% 
sulphuric acid, extract for twenty-four hours with ether in a continuous 
flow apparatus, add 30 cc. of water to the extract, and remove the ether by 
cautious distillation. To the residue add barium hydroxide solution to slightly 
alkaline reaction, heat for fifteen minutes on a water-bath, taking care that the 
solution remains slightly alkalme, then neutralize with N/4 hydrochloric 
acid, evaporate to 10 cc, and transfer to a loo-cc graduated flask, rinsing 
with 5 cc. of hot water and 95% alcohol. Make up to the mark with 95% 
alcohol, cool to 15° C. with shaking, and after thirty minutes at that tem- 
perature again make up to the mark, and allow to stand two hours longer 
at 15° C. Filter into a graduated cylinder, cool to 15°, read the volume 
of the filtrate, then evaporate in a platinum dish, ignite, cool, and titrate 
with N/4 hydrochloric acid. 

Calculate as in the Baragiola and Schuppli modification, taking 
account of the amount of wine used, the aliquot, and the strength of 
the standard solution. 

Determine free lactic acid in the same manner except that no sulphuric 
acid is added after distillation. 

Results obtained by Roettgen indicate that all or practically all of the 
lactic acid present in wine exists in the form of free lactic acid. 



* Zeits. Unters. Nahr. Genussm., 24, 1912, p. 113; 26, 1913, p. 437; 3°, iQ^S, P- 294; 
34, 1917,?- 198. 



734 FOOD INSPECTION AND ANALYSIS. 

Polarization. — Treat a measured amount of wine or cider with one- 
tenth of its volume of lead subacetate, filter and polarize the filtrate in 
the 200 mm. tube. The reading is increased by 10% for the true direct 
polarization. 

li the reducing sugars are also to be determined, the same solutions 
may be used for both the polarization and the reducing sugars as 
follows: 

Exactly neutralize with sodium hydroxide solution 200 cc. of the wine, 
using litmus paper as an indicator, and evaporate on the water-bath 
to about one-fourth its original volume. Wash with water into a 200 cc. 
flask, add enough normal lead acetate solution to clarify, and make up 
with water to the mark. Filter and to the filtrate add powdered sodium 
sulphate or carbonate sufficient to precipitate the lead, again filter and 
polarize before and after inversion (page 610). 

Determination of Reducing Sugars. — Determine reducing sugars 
in portions of the wine treated as described in the preceding section, after 
dilution so as not to contain above 0.5% of sugar for the Defren and the 
Munson and Walker methods or above 1% of sugar for the Allihn method. 
One may assume 2% as the sugar-free extract of wine, the number of 
volumes of water to be added to the filtrate being determined by the dif- 
ference between 2 and the total extract as determined. 

Determination of Glycerol. — In Dry Wines. — Evaporate 100 cc. of 
the wine in a porcelain dish on the water-bath to about 10 cc, add about 
5 grams of fine sand and from 3 to 4 cc. of milk of lime (containing about 
15% of calcium oxide) for each gram of extract present and evaporate 
nearly to dryness. Treat the moist residue with 50 cc. of 95% (by vol.) 
alcohol, remove the substance adhering to the sides of the dish with a 
spatula, and rub the whole mass to a paste. Heat on a water-bath, with 
constant stirring, to incipient boiling and decant through a filter into a 
small flask. Wash by decantation with 10 cc. portions of hot 95% alcohol 
until the filtrate amounts to about 150 cc. Evaporate the filtrate to a 
sirup on a hot, but not boiling, water-bath, transfer to a small glass- 
stoppered graduated cylinder with 20 cc. of absolute alcohol, and add 3 
portions of 10 cc. each of absolute ether, shaking throughly after each 
addition. Let stand until clear, then pour off through a filter and wash 
the cylinder with a mixture of absolute alcohol and absolute ether 
(1:1.5), pouring the wash liquor also through the filter. Evaporate the 
filtrate to a sirup, dry for one hour in a boiling-water oven, weigh, ignite, 
and weigh again. The loss on ignition gives the weight of glycerol. 



ALCOHOLIC BEVERAGES. 735 

A more accurate method is that proposed by Ross and described under 
vinegar, page 80 1. 

In Sweet Wines. — If the extract exceeds 5% heat 100 cc. to boiling 
in a flask and treat with successive small portions of milk of lime until the 
color becomes at first darker and then lighter. Wlien cool add -200 cc. 
of 95% alcohol, allow the precipitate to subside, filter, and wash with 95% 
alcohol. With the filtrate thus obtained proceed as directed for dry- 
wines. 

Determination of Potassium Sulphate.— Acidify 100 cc. of the sample 
with hydrochloric acid, heat to boiling, and add an excess of barium 
chloride solution. Filter, wash, dry, ignite, and weigh as barium sul- 
phate, calculating the equivalent of potassium sulphate. 

Determination of Sodium Chloride. — To 50 cc. of the wine add sodium 
carbonate solution until alkaline, evaporate, burn at low redness and 
determine chlorine gravimetrically as silver chloride. 

Detection of Nitrates.— E^^gr 1/d/zofi?.*— Treat a few drops of the 
wine in a porcelain dish with 2 or 3 cc. of concentrated sulphuric acid 
which contains about o.i gram of diphenylamin per 100 cc. The deep 
blue color formed in the presence of nitrates appears so quickly that 
it is not obscured, even in sweet wine, by the blackening produced by 
the action of sulphuric acid on the sugar. In the case of red wines 
clarify with lead subacetate, removing the excess with sodium sulphate. 

Determination of Tannin. — Neubauer-Lowenthal Method. "^ — The 
reagents are those given on pages 429 and 430, also finely pulverized bone 
black extracted with hydrochloric acid and washed with distilled water 
until neutral. It should be kept covered with water. 

Dealcoholize 100 cc, dilute with water to the original volume, transfer 
10 cc. to a porcelain dish of about 2 liters capacity, add about a liter of 
water and exactly 20 cc. of indigo solution. Add tenth -normal potassium 
permanganate solution, one cc. at a time, until the blue color changes 
to green, then a few drops at a time until the color becomes golden yellow. 
Designate the number of cubic centimeters of permanganate solution 
employed as "a." 

Treat 10 cc. of the dealcoholized wine, prepared as above, with bone- 
black for fifteen minutes; filter and wash thoroughly with water. Add a 
liter of water and 20 cc. of indigo solution and titrate with permanganate 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 (rev.) p. 88. 



736 FOOD INSPECTION AND ANALYSIS. 

as above. Designate the number of cubic centimeters of permanganate 
employed as " Z>." 

Then a—b = c, the number of cubic centimeters of permanganate 
solution required for the oxidation of the tannin and coloring matter in 
ID cc. of wine, i cc. = 0.004157 gram of tannin. 

Detection and Determination of Preservatives. — See Chapter XVIII. 

Detection of Colors. — Dupre Method.'^ — Dissolve i part of pure 
gelatin in 10 parts boiling water, pour upon a plate to harden and cut into 
2 cm, cubes. Immerse one of the cubes in the suspected sample, allow 
to remain for twenty-four hours, wash slightly in cold water, and cut 
through with a knife. If the color is a natural one, it will lightly tinge 
the outer surface of the cube, but will not permeate far below the surface, 
so that the inner portion of the cross-section will be largely free from color. 
Nearly all foreign coloring matters used in wine, such as most coal-tar 
dyes, cochineal, Brazil wood, logwood, etc., will be found to deeply per- 
meate the jelly cube often to the center. Information as to the nature of 
the color may sometimes be gained by immersing the dyed jelly cube in 
weak ammonia. If the color be rosanilin, the cube is decolorized; if 
cochineal, a purple coloration will result, and if logwood, a brown tinge. 

Cazeneuve Method. — Wliile by no means complete and not of recent 
origin the scheme of Cazeneuve (page 737) as condensed and arranged by 
Gautier (La Sophistication des Vins) will often be found helpful. If 
other colors than these are evidently present, tests should be made as 
indicated in Chapter XVII. Cazeneuve employs the following reagents: 

(i) Yellow oxide of mercury, finely pulverized, 

(2) Lead hydrate, freshly precipitated, well washed, suspended in 
about twice its volume of water; to be kept in a stoppered bottle; should 
be renewed after several days' use. 

(3) Gelatinous ferric hydrate, well washed from ammonia, suspended 
in about twice its volume of water. 

(4) Manganese dioxide, pulverized. 

(5) Concentrated, chemically pure sulphuric acid. 

(6) White wool, 

(7) Stannous hydrate, freshly precipitated, well washed, suspended in 
water, and kept from exposure to light and air. 

(8) Collodion silk, the artificial silk produced from nitro-cellulose. 
This fiber has a special affinity for basic dyes, 

* Jour. Chcm. Soc, 37, p. 572. 



ALCOHOLIC BEVERAGES. 



737 



To lo cc. of the wine are added 0.2 gram finely powdered yellow oxide of mercury. 
Boil and pour upon a double filter. 



Filtrate colored either before or after acidifying. 



CL P= 






Filtrate colored yellow. 10 cc. 
of the wine are warmed with 2 
grams lead hydrate. Filter. 



Filtfate colored yellow. 
A large excess of lead 
hydrate is added and 
the liquid is boiled. 



•-( '- r^ 



>^ 1 u i-i 



cl3 

CO o 



S 3 C(5 

'2'< c 






3 c - Q 



2 n 3- O 



(fl & —• ^. 



^^ 



(D 



3 CT ^ *-^ 



£3 3 



P P 2 -^ 



O 



h-. Q 3 






o ^ 

S S (T 

2- 51' 
3* 

"^ p o 

«-= 

*. '3 I. 

^""^ 
2.P S 

S 3 2. 



2.3 

"O re 



,-s i-f ■— ' -. H^ w >-( ^. ^ -J r: 



^ _ 

rt o 
55 _ 






3 3_ (T^ j^ p po 



nc ... 

L3 "-I Cfl 



p o" 



cSo 
ru 



?r o 



^ .^ 



° X 

t g 



o 5 



ft o 

o 
3. 
5 






^ OQ i£. 



"-^i i" S 6 

rD >~> p . ^ 



O 



(TO ^ 



Filtrate colored red. 10 
cc. of the wine are treated 
with 2 grams lead hydrate 
and filtered. 

3 Filtrate colorless. 



■•3 ^pg^ 
rr ? -a 
P ni ^ 3 

f-» >• fD 

CL -T- ►J. Ol 



Filtrate col- 
orless a f t e I 
acidifying. 



2. r? (Ti 



It-." 



1- 

ft) 
n'T3 




e^g 


(TO 


3- 


cr tT> 




^ 0- 





CO 



^ (TO 



o^p " o 

*^ ITT^ r^ ^T* 

« ^^3-5 

S^3 - 3 



^ CTO 



^^ >;! p 






5; ID n. 3" t;" c 



ft (TO T3 

era 



3- c c . 

3 O O '^ 

" ■ -^ fT 



O 3 p hJ 

(D 03 

P. m ^ 

<^ ^ ^• 

01 ^ o 

■ O 3 

>■ 3^ i*> 
n "^ 

j:^ '-^ (D 

lis. 

3 3 5 



3 a° 



clOq p 



3 I. 



p- p r3 p 
1 ^8 



3- p 


p 


"-^ 3 




_ 3 




'og 






m 


cr 


P 


rr 




C:'^ 





n n 



^^ ~-: rn ■«■' V ^■' » ^•' n >»^ V «. o c> f o ri s? >t o o _ ^ 5- 



Q O R O 



^ c ft 55 



:j Cl (^ 5?- 



•^ C^ Oo "^ ^..:b 



^ *^ i^ ^ ^ 






r, s 



•< O 



o 



cd w S ^ 



0^ ^ 

i ^ 

Co §. 

I 



738 FOOD INSPECTION AND ANALYSIS. 



MALT LIQUORS. BEER. 

In its widest sense beer may be defined as the product of fermentation 
of an infusion of almost any farinaceous grain with variov.s hitter extract- 
ives, but unless otherwise qualified it should be strictly apphed to the 
beverage resulting from the fermentation of malted barley and hops. 
In the manufacture of beer two distinct processes are employed, viz., 
malting or sprouting the grain, and brewing. Many brewers do noth- 
ing but the latter, buying their malt already prepared. 

Malting. — For the preparation of malt, the barley is steeped in water 
for several days, after which the water is drained off and the moist grain 
is "couched," or piled in heaps, on a cement floor, where it undergoes a 
spontaneous heating process, during which it germinates, forming the 
ferment diastase. When the maximum amount of diastase has been 
produced, indicated by the length of growth of the sprout, or "acrospire " 
within the grain, the germination is checked by spreading the grain in 
layers over a perforated iron floor, and finally subjecting it to artificial 
heat. The character of the malt and of the beer produced from it depends 
largely on the heat at which the "green" malt is kiln dried. If dried 
between 32° and 37° C. it forms pale malt, which produces the lightest 
grades of beer. Most beer is made from malt dried at higher tem- 
peratures, say from 38° to 50°, the depth of color of the liquor var}ing 
with the heat to which the malt has been subjected, while the color of the 
malt varies from the "pale" through the "amber" to "brown," or even 
black. The darkest grades are sometimes dried at temperatures over 
100° C, even to the point where the starch becomes caramelized. 

A more modem method consists in the so-called pneumatic malting, 
wherein the whole operation is conducted in a large rotating drum, which 
holds the grain, and in which the temperature and moisture at different 
stages is carefully controlled by the admission to the interior of the drum 
of moisture- laden or dry air, heated to the required degree. 

The chief object of malting is the production of diastare, which by 
its subsequent action on the starch converts it into the fermentable sugars 
maltose and dexrin. i\Ialt contains much more diastase than is necessaiy 
to convert the starch simply contained therein to maltose, and is capable 
of acting on the starch of a considerable quantity of raw grain, such 
as corn or rice, when mixed with it. This practice of using other grains 
than malt is prohibited in some localities, such as Bavaria. 



ALCOHOLIC BEVERAGES. 739 

Brewing. — The malt, or mixture of malt and raw grain, is first crushed 
and "mashed" by stirring with water in tubs at 50° to 60° C, finally 
heating to 70°. During this process the conversion of the starch to mal- 
tose and dextrin takes place. The re.udting hquor is known as "wort," 
containirg, besides mahose and dextrin, peptones and amides. The 
clear wort is then drawn off from the residue, and boiled to concentrate 
the product and to sterilize it, after which hops (the female flower of 
the Humiilus lupulus) are added and the boihng continued. Hops 
contain resins, bitter principles, tannic acid, and a pecdiar essential oil, 
all of which are to some extent imparted to the wort. After cooling and 
settling, the clear wort is run into fermenting-vats, where selected yeast, 
usually saccharomyces cerevisice, is added, and the alcoholic fermentation 
allowed to proceed. The temperature greatly affects the character of 
the fermentation. If kept between 5° and 8° C, a slow fermentation 
proceeds, known as bottom fermentation, during which the yeast settles 
out at the bottom. This is much more easily controlled than the 
quick or top fermentation, which takes place at from 15° to 18°, much 
of the yeast in the latter case being carried to the surface, from which it 
is finally removed by skimming. In either case the yeast feeds upon 
the albuminous matter present. At the proper stage the beer is drawn off 
from the larger portion of the yeast, and run inta casks, or tuns, in which 
an after-fermentation proceeds. The beer is finally clarified by treatment 
with gelatin or beech shavings 01 chips, to which the floating yeast-cells 
and other impurities attach themselves. It is finally stored in barrels 
coated with brewers' pitch, or pasteurized at 60° C. and bottled. 

Varieties of Beer. — Formerly the division of beers into "lager," 
"schenk," and "bock" was made by reason of the fact that beer had to 
be brewed ujider certain climatic conditions and at certain seasons only. 
Now, with improved means for artificial refrigeration, and with better 
methods controlling all stages of the process, these distinctions are less 
marked. 

Lager Beer (from lager, a storehouse) is a term originally applied to 
Bavarian beer, but is now given to any beer that has been stored several 
months. Formerly lager beer was made early in the winter, and stored 
in cool cellars till the following spring or summer, during nearly all of 
which time a slow after-fermentation took place. The best lager beers 
contain a low proportion of hops, and are high in extract and 
alcohol. 

Schenk Beer is a quickly fermented beer made in winter for immedi- 



740 



FOOD INSPECTION AND ANALYSIS. 



ate use. It is brewed in from four to six weeks and will not keep long 
without souring. 

Bock Beer, according to older systems of nomenclature, occupied a 
middle place between lager and schenk, being an extra strong beer brewed 
for spring use and made in limited quantities, not being intended for 
storage. 

Berlin Weiss Bier is prepared by the quick or top fermentation of a 
wort consisting of a mixture of malted barley and wheat with hops. It is 
high in carbon dioxide, being usually bottled before the second fermen- 
tation has ended. 

Ale is virtually the English name for beer. It is usually lighter colored 
than lager beer, being made from pale malt by quick or top fermentation, 
and containing rather more hops than beer. It has a high content of 
sugar, due to checking fermentation at an earlier stage than in ordinary 
beer. 

Porter is a dark ale, the deep color of which should be due to the use 
of brown malt dried at a high temperature, but which is sometimes colored 
by the admixture of caramel. It has a large extract, chiefly sugar. 

Stout is an extra-strong porter, being high both in alcohol and extract. 

Composition of Beer. — Beer is a somewhat complex liquor. Besides 
water, alcohol, and sugar, it contains carbon dioxide, succinic acid, dex- 
trin, glycerin, tannic acid, the resinous bitter principles of hops, nitrog' 
enous bodies (chiefly peptones and amides), alkaline and lime salts 
(chiefly phosphates), fat (traces), acetic acid and lactic acid. The latter 
acid constitutes the chief fixed acid of beer. 

The following analyses of different varieties of beer are due to Konig: 



I 



Variety. 









o <u 



•3 (U 












c 3 


Ul lU 


•«a 










Vi 


fe-£ 


S-H 


•n 








C5" 


:2rt 


5 


< 


0.74I 0.95 


3-II 


0.156 


0.12 


0.204 


0.71 


0.88 


3-73 


0.151 


0.165 


0.228 


0.74 


1.20 


3-47 


0.161 


o.i^4 


0.247 


0-73 


I. 81 


3-97 


0.165 


0.176 


0.263 


o.s8 


1.62 


2.42 


0.392 


0.092 


0.149 


0.65 


2.62 


3.08 


0.281 




0-363 


O.&I 


1.07 


1. 81 


0.278 




0.31 






Schenk 

Lager 

Export beer 

Bock 

Weiss bier. . 

Porter 

Ale 



205 
258 
109 
84 
26 
40 
38 



.0114 
.0162 
.0176 
.0213 

■0137 
.0191 
.0141 



I 
91. II 0.197 

90.08 o.ig6 

209 



87.87 
91.63 
88.49 
89.42 



0.234 
0.297 
0.215 
0.201 



-36 

-93 
.40 
.69 

-73 
.70 

•75 



5-34 
5.70 
6.38 
7.21 
5-34 
6-59 
5-65 



•05s 

.077 

0.074 

0.089 

-034 

•093 
.086 



Fifteen samples of lager beer and seven samples of pale ale, bought 
in Massachusetts bar- rooms, representing as nearly as possible the quality 



ALCOHOLIC BEVERAGES. 



741 



of liquor sold every day to patrons by the bottle or glass, were analyzed 
by the Board of Health with the following results: 



Per Cent of 

Original Wort 

Extract. 




Per Cent of 
Extract. 



Beer — Maximum 

Minimum. 

Mean 

Pale ale — Maximum 

Minimum. 

Mean 



18.91 

7-33 
15.04 

15-99 
10-95 
13-56 



.76 

.67 
.92 
-47 
-38 
-54 



Five out of the 15 beer samples and 3 out of the 7 ale samples con- 
tained salicylic acid. 

The percentage composition of the ash of German beer is thus given 
by Konig as the mean of 19 analyses: 



Ash in 

100 Parts 

Beer. 


Potash. 


Soda. 


Lime. 


Magnesia. 


Iron 
Oxide. 


Phos- Sul- 

phoric phuric Silica. 

Acid. Acid. 


Chlorine, 


0.306 


33-67 


8.94 


2.78 


6.24 


0.48 


31-35 3-47 


9.29 


2.93 



Malt and Hop Substitutes. — By reason of the fluctuation in market 
price of these two chief constituents of beer, it sometimes becomes a 
question of economy to employ cheaper substitutes wholly or in part 
for one or the other. There are two classes of malt substitutes, (i) those 
which, like corn grits, rice, and wheat, are mixed directly with the malt 
before " mashing," and, like the malt, have to undergo a saccharous fer- 
mentation before being acted on by yeast, and (2) such substances as cane 
sugar, invert sugar, brewers' sugar, and dextrin, which are added to the 
wort at a later stage in the brewing, just before the addition of the yeast, 
being in condition to be readily acted on by the latter. 

Brewers' sugar is the com.mon substitute of the second class because 
of the fact that its sugars much resemble those of malt, and are in readily 
fermentable form. Diastase forms from the malt dextrin and maltose, 
while brewers' sugar contains dextrin, maltose, and dextrose. 

When the price of malt is abnorm.ally high, the addition of brewers' 
sugar may be economical, but when ordinary conditions prevail, the cost 
of the two, figured with reference to their yield in alcohol and extract, 
is about the same. Aside from the question of economy, however, there 
are advantages in the use of malt substitutes, such as diminishing the 
nitrogenous content of the wort without lessening the alcohol or extract 
yielded. 



742 FOOD INSPECTION AND ANALYSIS. 

The nitrogenous matter left after fermentation is one of the chief 
causes of cloudiness or, turbidity in the finished product, and is some- 
times difficult to remove. By the use of brewers' sugar, especially in 
clear bottled ales and sparkling pale beers, the appearance of the product 
is much enhanced. The temptation at times to add more than is necessary 
to accomplish this is great. A high-grade malt may have as much as 40% 
of brewers' sugar added to its wort and still produce an acceptable beer. 
With a low-grade malt, brewers' sugar yields a very poor quality of beer. 
Hence its use may or may not be desirable, though it can hardly be con- 
sidered unqualifiedly as an adulterant. 

As to the employment of hop substitutes, the question of relative price 
again enters in. Only when the price of hops is high is there any special 
inducement to use substitutes. Quassia wood, chiretta, gentian, and 
calumba, all of which yield bitter principles, have been used in beer, 
and cannot be considered detrimental to health. Allen and Chattaway 
have found the first two in beer examined by them.* Such poisonous 
substances as cocculus indicus, picric acid, and strychnine are alleged to 
have been used as hop substitutes, but there is no authentic record of any 
of them having been found in recent years, if at all. 

Adulteration of Malt Liquors and Standards of Purity. — The Joint 
Committee on Standards adopted in 1908 the following standards: 

Malt Liquor is a beverage made by the alcoholic fermentation of 
an infusion, in potable water, of barley malt and hops, with or without 
unmalted grains or decorticated and degerminated grains. 

Beer is a malt liquor produced by bottom fermentation, and contains 
in 100 cc, at 20° C, not less than 5 grams of extractive matter and 0.16 
gram of ash, chiefly potassium phosphate, and not less than 2.25 grams of 
alcohol. 

Lager Beer, Stored Beer, is beer which has been stored in casks for 
a period of at least three months, and contains, in 100 cc, at 20° C, not 
less than 5 grams of extractive matters, and 0.16 gram of ash, chiefly 
potassium phosphate, and not less than 2.50 grams of alcohol. 

Malted Beer is beer made of an infusion, in potable water, of barley, 
malt, and hops, and contains, in 100 cc, at 20" C, not less than 5 grams 
of extractive matter, nor less than 0.2 gram of ash, chiefly potassium 
phosphate, not less than 2.25 grams of alcohol, not less than 0.4 gram 
of crude protein (nitrogen X 6.25). 

* Analyst, 12, 112. 



ALCOHOLIC BEVERAGES. 



743 



Ale is a malt liquor produced by top fermentation, and contains, in 
loo cc, at 20° C, not less than 2.75 grams of alcohol, nor less than 5 grams 
of extract, and not less than 0.16 gram of ash, chiefly potassium phosphate. 

Porter and Stout are varieties of malt liquors made in part from highly 

roasted malt. 

Non-injurious bitter principles are no doubt employed in place of 
hops, and unless the liquor is sold for a pure malt beer, they cannot be 
regarded as adulterants. 

The tendency to shorten the time of storage of beer, or to sell it without 
storing at all, lessens or does away with the after-fermentation, resulting 
in a lack of " life " or effervescence in the product. This is sometimes 
made up by the addition of sodium bicarbonate. 

Distinction between Malted and Non-malted Liquors.— In some 
states where strict prohibitory liquor laws are in force, it is illegal to sell 
" malt liquors," so that when convictions are obtained, it is necessary 
for the analyst to distinguish between liquors brewed wholly or in part 
from malt and those in which no malt has been used, but which were 
brewed entirely from malt substitutes. This distinction is not always 
easy to make with precision. In the absence of malt, brewers' sugar is 
usually the source of alcohol in these beverages. Parsons * has shown 
that the most striking points of difference between malted and non-malted 
liquors are in their per cent of phosphoric acid and proteins, and that 
malted beer or ale should contain not less than 0.04% P2O5, and 0.25% 
protein (NX6.25). A low ash and high content of sulphates in the ash 
are also indicative of brewers' sugar. The following analyses made by 
Parsons clearly show these distinctions: 



COMPOSITION OF SEVENTY-SIX SAMPLES OF AMERICAN MALT LIQUORS. 





Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


Extract. 


Protein 
(N X6.25) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates in 
Ash. 


Free 
Acid. 


Average 

Maximum. . . . 
Minimum. . . . 


I .0100 
I. 0210 
1.0047 


S.61 
785 
0-35 


4.61 
7.64 
3-15 


0.470 
0.614 
0. 290 


0.061 
0.095 
0.045 


0.209 
0.296 
0.147 


6.34 

12.67 

2.44 


0. 26 
0.87 
0. 10 



* Jour. Am. Chem. Sec, 1902, 24, 1170. 



744 FOOD INSPECTION AND ANALYSIS. 

TYPICAL ANALYSES OF BEERS APPARENTLY NOT BREWED FROM MALT. 



Number. 


Specific 
Gravity. 


Alcohol 
by Vol- 
ume. 


Extract. 


Protein 
(NX6.25) 


Phos- 
phoric 
Acid. 


Ash. 


Sul- 
phates. 


Free 
Acid. 


I 


I . 0074 
I . 0098 
1.0062 
1. 01 1 2 
I. 0041 


1.68 
2.63 
2.27 

2. II 

1.85 


2.52 
3 40 
2.25 
3-53 
1-73 


0. 114 
0.215 
0.150 

0.133 
0.031 


O.OIO 

0.023 
0.015 
0.015 

O.OIO 


0. 19 
0. 180 
0.124 
0. 140 
0.088 


21 . 22 

11.30 
10.81 
12.50 


Normal 


2. . . 


(( 


2 


1 ( 


4 

e 


" 







The ash of the fifth sample is thus compared with that of the average 

beer as given by Blyth : 

Malt Beer " No-malt " Beer 
(Blyth). (Parsons). 

K2O 37-22 12.93 

Na20 8.04 19.61 

CaO 1-93 Undetermined 

MgO 5-51 

FeaOs Trace 

SO3 1-44 10.81 

P2O5 32-09 10.71 

CI 2.91 21.76 

Si02 10.82 7.50 

Distinction between all Malt and Malt Substitute Liquors. — In coun- 
tries other than Bavaria a considerable, if not the larger part, of the malt 
liquors is brewed from part malt and part malt substitutes such as rice, 
corn grits, cerealin, etc. While the use of the malt substitutes produces a 
product of a somewhat different character from all malt beer and ale this 
is not necessarily inferior, in fact it is preferred by many consumers. There 
exists, nevertheless, a strong prejudice in favor of the all-malt product to 
meet which that brewed in part from substitutes has often been misbranded 
so as to convey the impression that it was brewed solely from malt and hops. 

Tolman and Riley,* who have investigated the production of both 
types of malt liquors, find that the all-malt products contain higher per- 
centages of ash, proteins, and phosphoric acid when calculated to a uniform 
wort basis. These distinctions are clearly brought out by their results 
calculated to the basis of wort containing 15^, of solids given in the table 
on page 745. In making the calculation the percentage of solids in the 

* U. S. Dept. of Agric, Bui. 493, 191 7. 



ALCOHOLIC BEVERAGES. 



745 



original wort was first obtained by multiplying the per cent by weight of 
alcohol by 2 and adding the per cent by weight of extract. 



ASH, PROTEIN, AND PHOSPHORIC ACID IN M.\LT LIQUORS OF KNOWN 

ORIGIN. 



Raw Materials. 



Malt. 



Malt 80%, rice 20%. 

" 66 ■ " 34 • 

" 62 " 38 . 

" 55 " 45 • 

" 50 " 50 . 



Malt 70%, corn 30% . 



70 



60 
60 
60 
45 



30 
32 
32 
32 
40 
40 
40 
55 



Malt 65%, cerealin 35%. 
80 



78 
78 
78 
75 
75 
75 
65 
65 
65 



22 
22 
22 
25 
25 
25 
28 
28 
28 



brewer's sugar 7% 

" 7 
<t "7 



Product. 



Beer 

(21 samples) 
Maximum 
Minimum 
Average 

Beer 



Maximum 



Beer 



Maximum 

Beer 

Ale 



Maximum 



Ash. 



0-336 
0.230 
0275 



o. 202 
0.198 
0.205 
o. 148 
o. 167 



0.205 



0.199 
0,188 
0.150 
0.I8I 

o. 164 

0.215 
0.188 

o. 223 

0.145 



0.223 



o. 192 

0.215 

o. 176 
0.169 

0.I8I 

o. 204 
o. 196 
o. 191 

0.185 
0.175 

o. 166 



0.213 



Protein 
(NX6.2S). 



1.079 
o. 701 
0.870 



0.517 
0.555 
0.488 
0.380 
0.351 



O.S5S 



0.343 
0.367 
0.461 
0.466 
0.459 
0.563 
0.593 
0.597 
0.347 



0.597 



0.483 
0.480 

0.455 
0.476 
0.502 

0.499 
0.509 
0.502 
0.409 
0.443 
0.427 



Phosphoric 

Acid 

(P2O6). 



0.509 



0.143 
0.087 
0.109 



0.073 
0.084 
0.061 
0.077 
0.056 



0.084 



0.057 
0.065 
0.057 
0.062 
0.056 
0.074 
0.076 
0.074 
0.057 



0.076 



0.057 
0.051 
0.050 
0.04s 
0.040 
0.044 
0.044 
0.043 
0.037 
0.040 
0.041 



0.051 



746 FOOD INSPECTION AND ANALYSIS. 

Preservatives in Beer. — Antiseptics are frequently added to malt 
liquors, salicylic acid being most commonly used. Fluorides of ammo- 
nium and sodium have been found in American beer. Other preserva- 
tives to be looked for are benzoic acid and sulphites. Beer casks are 
frequently " sulphured " or fumed with a solution of calcium bisulphite, 
so that the beer may derive its content of sulphites from this source. 

In case of police seizure of beer sold in bulk or in opened bottles for 
the purpose of ascertaining whether or not their alcoholic content exceeds 
certain limits fixed by law, a little formalin had best be added as soon as 
possible after the seizure to prevent further fermentation. This is espe- 
cially desirable in cases where there is likely to be some delay in making 
the analysis, so as to forestall any claim on the part of the defendant of 
additional alcohol being formed after the seizure. From 6 to 8 drops of 
a 40% solution of formaldehyde to a quart of beer is sufficient, and this 
quantity will not appreciably affect the analysis. 

Arsenic in Beer. — In 1900 a very disastrous epidemic of arsenical 
poisoning occurred in Manchester, England, involving several thousand 
cases, many of which were fatal. The arsenic was traced to sulphuric 
acid, which entered into the manufacture of commercial glucose used 
in the beer, the acid found so highly arsenical being made from a certain 
variety of Swedish pyrites, abnormally high in arsenic. The evidence 
was conclusive that the beer was the sole cause of the trouble. While the 
presence of arsenic was in this case accidental, carelessness was shown on 
the part of those having to do with the purity of the materials entering into 
the composition of the beer. Further details are given by Kelynack 
and Kirby.* Fortunately no other instances are on record of arsenical 
poisoning from malted liquors. A large number of samples of American 
beer have been examined in the laboratory of the Food and Drug Depart- 
ment of the Massachusetts State Board of Health, and only insignificant 
traces of arsenic have in any case been found. 

Temperance Beers and Ales. — Many varieties of these so-called tem- 
perance drinks are home-made, as well as sold on the market. They are 
usually slightly fermented infusions of various roots and herbs, including 
ginger or sassafras, with molasses or sugar and yeast, and more often 
contain less than 1% of alcohol by volume. Among them are included 
spruce beer, and the various root beers, such as ginger beer and ginger 
ale. The latter beverages are generally carbonated. Numerous brands 



* Arsenical Poisoning in Beer Drinkers, London, 1901. 



ALCOHOLIC BEVERAGES, 747 

of bottled beer are manufactured, which contain virtually the same body 
and characteristic flavor as lager beer, but less alcohol. Indeed the com- 
position of many of these beverages is identical with that of lager beer, 
excepting in alcoholic content, being made by substantially the same 
process and out of the same ingredients, but with the alcohol finally 
removed by steaming, so that the liquor comes within the limits of a 
temperature beverage. Of this class is Uno beer, which ranges from 
0.6 to 0.9 per cent in alcohol. 

METHODS OF ANALYSIS OF MALT LIQUORS.* 

Preparation of Sample.— Transfer the contents of the bottle or bottles 
to a large flask and shake vigorously to hasten the escape of carbon dioxide, 
care being taken that the liquor is not below 15° C, since below this 
temperature the carbon dioxide is retained by the beer and is liable to form 
bubbles in the pycnometer. 

Specific Gravity. — See page 686. 

Ash. — Determine in 25 cc. by evaporation and ignition at dull redness. 

Determination of Alcohol. — From the Specific Gravity of the Dis- 
tillate. — Proceed as described on page 687, employing 100 cc. of the liquor, 
and determining the specific gravity at 15.5° C. If the liquor is markedly 
acid, add first o.i to 0.2 gram of precipitated calcium carbonate. 

From the Refraction of the Distillate. — Prepare the distillate as 
described on page 687, except that it is made up to the mark at 17.5° C. 
Determine the refraction at 17.5° C. by means of the immersion refrac- 
tometer, and calculate the alcohol by the table on page 748. 

Determination of Extract. — In cases where extreme accuracy is 
desired, the result obtained by evaporating at 100° a weighed amount 
of the beer cannot be accepted, on account of the dehydration of the 
maltose at a temperature exceeding 75° C. Unless the evaporation is 
conducted at that temperature (a difficult operation), a closer approxi- 
mation to the truth is obtained, especially with beer high in sugar, by 
calculation as follows: 

From the Specific Gravity. — Evaporate a measured quantity of the 
beer to one-fourth its volume on the water-bath, make up with water 
to its original measure, and determine the specific gravity of the deal- 
coholized beer. Then by means of Schultz and Ostermann's table, pp. 
749-753, calculate the extract corresponding, 

* Barnard, U. S. Dept. of Agric, Bur. of Chem., Circ. 3^' 



748 



FOOD INSPECTION AND ANALYSIS. 



ACKERMANN AND STEINMANN'S TABLE FOR OBTAINING THE PER- 
CENTAGE OF ALCOHOL IN THE DISTILLATE OF BEER FROM THE 
IMMERSION REFRACTOMETER READINGS * 



u 

V 

V ■ 






(U . 
g M 


•3 -So 




u 

(U 
■♦J 

lU . 
C 60 

§.S 






u 

« . 

5 M 
O.S 




■03" 












•§"0 c3 

8>^ 




J3 <u t" 


tl^ 






oP*CU 


Pi 


< 


< 


rt 


< 


< 


Pi 


< 


< 


p^ 


< 


< 


15.0 


0.00 


0.00 


17.2 


1.38 


1-74 


19.4 


2-74 


3-46 


21.6 


4.02 


5.06 


I5-I 


0.06 


0.08 


17-3 


1.44 


1.82 


19-5 


2.80 


3 


53 


21.7 


4 


.07 


5-13 


15.2 


0.13 


0.16 


17.4 


I-51 


1.90 


19.6 


2.86 


3 


61 


21.8 


4 


•13 


5.20 


15-3 


0.19 


0.24 


17-5 


1-57 


1.98 


19.7 


2.91 


3 


68 


21.9 


4 


.18 


5.26 


15-4 


0.25 


0.32 


17.6 


1.63 


2-05 


19.8 


2-97 


3 


75 


22.0 


4 


22 


5-32 


I5-S 


0.32 


0.40 


17.7 


1.68 


2.12 


19.9 


3-04 


3 


83 


22.1 


4 


28 


5-39 


15-6 


0.38 


0.48 


17.8 


1-74 


2.20 


20.0 


3.10 


3 


90 


22.2 


4 


33 


S-46 


iS-7 


0.44 


0.56 


17.9 


1. 81 


2.28 


20.1 


3-15 


3 


97 


22.3 


4 


39 


5-53 


15-8 


0.50 


0.64 


18.0 


1.87 


2.36 


20.2 


3.20 


4 


04 


22.4 


4 


44 


5-59 


15-9 


0-57 


0.72 


18. 1 


1-93 


2.44 


20.3 


3.26 


4 


II 


22.5 


4 


49 


5-65 


16.0 


0.64 


0.80 


18.2 


2.00 


2.52 


20.4 


3-33 


4 


19 


22.6 


4 


54 


5-72 


16. 1 


0.70 


0.88 


18.3 


2.06 


2.60 


20.5 


3-38 


4 


26 


22.7 


4 


59 


S-78 


16.2 


0.77 


0.96 


18.4 


2-13 


2.68 


20.6 


3-43 


4 


33 


22.8 


4 


64 


5-85 


16.3 


0.83 


1.04 


18.5 


2.19 


2.76 


20.7 


3-50 


4 


41 


22.9 


4 


70 


5-92 


16.4 


0.88 


1. 12 


18.6 


2.25 


2.84 


20.8 


3.56 


4 


48 


23.0 


4 


76 


6.00 


16-5 


0.95 


1. 19 


18.7 


2.31 


2.92 


20.9 


3.61 


4 


55 


23.1 


4 


81 


6.07 


16.6 


1. 01 


1.27 


18.8 


2.37 


2-99 


21.0 


3-67 


4 


63 


23.2 


4 


86 


6.13 


16.7 


1.05 


^■33 


18.9 


2.43 


3-07 


21. I 


3-73 


4 


71 


23-3 


4 


92 


6.20 


16.8 


1-13 


1-43 


19.0 


2.49 


3-14 


21.2 


3-78 


4 


77 


23-4 


4 


97 


6.27 


16.9 


1. 19 


I-5I 


19.1 


2.55 


3.22 


21-3 


3.84 


4 


84 


23-5 


5 


02 


6-33 


17.0 


1-25 


1.58 


19.2 


2.61 


3-29 


21.4 


3-90 


4 


92 








17. 1 


1.32 


1.66 


19-3 


2.68 


3-37 


21-5 


3-96 


4 


99 









* Zeits. gesamte Brauwesen, 28, 1903, p. aS9. 

From the Refraction. — Method of Ackermann and Foggenburg. — 
Determine the refraction of the liquor at 17.5° C. by means of the immer- 
sion refractometer. Determine also the refraction of the distillate from 
100 cc. of the liquor at 17.5° C, after making up to its original volume. 
In order to secure accurate results, care should be taken to cool the prism 
of the instrument to exactly 17.5° C. by im.mersing for five minutes in the 
water-bath previous to taking the refraction of the liquids. If determina- 
tions are made on a number of samples, this cooling is not necessary except 
before taking the reading of the first of the series. 

Calculate the grams of extract (E) from the refracdon of the liquor 
(R) and of the distillate (R') by the following formula: 

£ = 0.25705(7? -i?'). 

The extract is more conveniently obtained from Ackermann's table 
given on page 755. 



ALCOHOLIC BEVERAGES. 



749 



EXTRACT IN BEER WORT * 
[According to Schultz and Ostermann.] 





Extract. 


Specific 


Extract. 


Specific 


E.xtract. 


Specific 


Extract. 


Specific 


► 
















Gravity 


Per 


Grams 


Gravity 


Per 


Grains 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 

per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

bv 
Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
1 00 cc. 


at is°C. 


Cent 

by 

Weight 


I .0000 


0.00 


0.00 


I .006s 


1 . 69 


1.70 


I. 0130 


3-35 


3.39 


I. 0195 


5- 06 


5.16 


I .0001 


0.03 


0.03 


I .0066 


1.72 


1-73 


I .0131 


3.38 


3-42 


1 .0196 


5.09 


S.19 


I .0002 


0.05 


0.05 


I .0067 


1-74 


I.7S 


I .0132 


3-41 


3-46 


I. 0197 


S.I2 


S-22 


I .0003 


0.08 


0.08 


I .0068 


1.77 


1.78 


I. 0133 


3-43 


3.48 


I .0198 


S-iS 


S.25 


I .0004 


0. 10 


. 10 


I .0069 


1.79 


1.80 


I. 0134 


3-46 


3-51 


1 .0199 


S-I7 


S.27 


I .0005 


0.13 


0.13 


I .0070 


1.82 


1.83 


I. 0135 


3.48 


3-53 


I .0200 


5.20 


S.30 


I .0006 


0. 16 


0. 16 


I .0071 


1.84 


1.85 


I. 0136 


3-Si 


3.S6 


I .0201 


5-23 


S.34 


I .0007 


0.18 


0.18 


I .0072 


1.87 


1.88 


I. 01 37 


3-54 


3-59 


I .0202 


S.2S 


S.36 


I .0008 


0.21 


. 2r 


1.0073 


I .90 


1. 91 


I 0138 


3.56 


3.61 


I .0203 


S.28 


5-39 


I .0009 


0. 24 


0. 24 


I .0074 


1.92 


1-93 


I. 0139 


3-59 


3.64 


I .0204 


S.30 


S.4I 


1 .0010 


0. 26 


0. 26 


1.0075 


1.9s 


1 .96 


I .0140 


3.61 


3-66 


1 .0205 


5-33 


S.44 


1 .001 1 


0. 29 


0. 29 


I .0076 


1.97 


1.98 


I .0141 


3-64 


3-69 


I .0206 


S.35 


S.46 


I .0012 


0.31 


0.31 


1.0077 


2.00 


2 .02 


I .0142 


3.66 


3-71 


I .0207 


S.38 


S-49 


I .0013 


0.34 


0.34 


I .0078 


2 . 02 


2 .04 


I. 0143 


3.69 


3.74 


I .0208 


5-4° 


5-51 


I .0014 


0.37 


0.37 


I .0079 


2.05 


2.07 


I .0144 


3-72 


3.77 


I .0209 


5-43 


5-54 


I .0015 


0.39 


0.39 


I .0080 


2.07 


2 .09 


I. 0145 


3-74 


3-79 


I .0210 


S.4S 


5.S6 


I .0016 


0.42 


0.42 


I .0081 


2. 10 


2.12 


I .0146 


3-77 


3.83 


I .0211 


S.48 


5.60 


1 .0017 


0.4s 


0.4s 


I .0082 


2.12 


2.14 


I. 0147 


3.79 


3.8s 


I .021 2 


S-So 


5.62 


I .0018 


0.47 


0.47 


I .0083 


2. IS 


2.17 


I .0148 


3.82 


3-88 


I .0213 


5-53 


5.6s 


I .0019 


0. so 


0.50 


I .0084 


2.17 


2.19 


I .0149 


3.85 


391 


I .0214 


S-SS 


S.67 


I .0020 


0.52 


0.52 


I .0085 


2.20 


2. 22 


I -0x50 


3.87 


3-93 


I.02XS 


S-57 


S.69 


I .0021 


o-SS 


0.55 


I .0086 


2.23 


2.25 


1.0151 


3-9° 


3.96 


I .0216 


5 -60 


S.72 


I .0022 


0.58 


0.58 


I .0087 


2.25 


2.27 


I. 0152 


3-92 


3-98 


I .0217 


5.62 


5-74 


1.0023 


0.60 


0.60 


1.0088 


2. 28 


2.30 


I.OI53 


3-95 


4.01 


I .0218 


5.6s 


5.77 


I .0024 


0.63 


0.63 


I .0089 


2.30 


2.32 


I. 0154 


3-97 


4.03 


1 .0219 


S-67 


5-79 


i.002S 


0.66 


0.66 


I .0090 


2.33 


2.3s 


I-OI55 


4.00 


4.06 


I .0220 


S.70 


S.85 


I .0026 


0.68 


0.68 


I .0091 


2.35 


2.37 


I. 0156 


4-03 


4.09 


I .0221 


5-72 


.-;.8.' 


I .0027 


0.71 


0.71 


I .0092 


2.38 


2 .40 


I. 0157 


4.0s 


4. 11 


I .0222 


5-75 


.■i.«*t 


I .0028 


0.73 


0.73 


1.0093 


2.41 


2.43 


1.0158 


4.08 


4.14 


r .0223 


5.77 


i .00 


I .0029 


0. 76 


0. 76 


I .0094 


2.43 


2.4s 


I. 0159 


4.10 


4-17 


I .0224 


5.80 


.■^ 93 


I .0030 


0.79 


0.79 


I .0095 


2.46 


2.48 


I .0160 


4-13 


4. 20 


I .0225 


5.82 


S-9S 


1.0031 


0.81 


0.81 


I . 0096 


2.48 


2.50 


I .0161 


4.16 


4.23 


1 .0226 


5.84 


5.97 


1.0032 


0.84 


0.84 


I .0097 


2.51 


• 2.53 


I .0162 


4.18 


4-25 


I .0227 


S.87 


6.00 


1-0033 


0.87 


0.87 


I . 0098 


2.53 


2.SS 


I .0163 


4.21 


4.28 


I .0228 


5.89 


6 . 02 


1.0034 


0.89 


0.89 


I .0099 


2.56 


2.59 


I .0164 


4.23 


4-30 


I .0229 


5-92 


6.06 


1.003s 


0. 92 


0.92 


I .0100 


2.58 


2.61 


I. 016s 


4. 26 


4-33 


1.0230 


5. 94 


6.08 


I .0036 


0.94 


0.94 


I .0101 


2.61 


2 . 64 


I . 0166 


4.28 


4-3S 


I. 0231 


5-97 


6. II 


1.0037 


0.97 


0.97 


I . 0102 


2.64 


2.67 


I .0167 


4.31 


4.38 


I .0232 


S-99 


6.13 


1.0038 


1 .00 


1 .00 


I. 0103 


2.66 


2.69 


I. 0168 


4-34 


4.41 


1.0233 


6 . 02 


6.16 


1.0039 


1 .02 


1 .02 


I . 0104 


2 . 69 


2.72 


I .01(39 


4.36 


4-43 


1.0234 


6.04 


6.18 


1 .0040 


I. OS 


I. OS 


I. 0105 


2.71 


2.74 


I .01 70 


4-39 


4.46 


1.0235 


6.07 


6. 21 


I .0041 


1.08 


1.08 


I .0106 


2.74 


2.77 


I .0171 


4.42 


4. SO 


1 .0236 


6.09 


6.23 


I .0042 


1 . 10 


1 . 10 


I .0107 


2. 76 


2.79 


I .0172 


4-44 


4.52 


1.0237 


6. II 


6.25 


1.0043 


1.13 


I-I3 


I .0108 


2.79 


2.82 


I .0173 


4-47 


4.5s 


1 .0238 


6. 14 


6. 29 


1 .0044 


1. 15 


1.16 


I .0109 


2.82 


2.8s 


I. 0174 


4-50 


4.58 


I. 0239 


6.16 


6.31 


1 .004s 


1. 18 


1.19 


I .0110 


2.84 


2.87 


I.OI75 


4-53 


4.61 


I .0240 


6. 19 


6.34 


1 .0046 


1 . 21 


I . 22 


I .0111 


2.87 


2.90 


I .0176 


4-55 


4.63 


I .0241 


6.21 


6.3« 


I .0047 


1-23 


1.24 


I .011 2 


2.89 


2 92 


I. 0177 


4-58 


4.66 


I .0242 


6. 24 


6.39 


1 .0048 


1 . 26 


1.27 


I .0113 


2.92 


2.9s 


I .0178 


4^ 61 


4 69 


1.0243 


6.26 


6.41 


I .0049 


1.29 


1.30 


I .0114 


2.94 


2.97 


I. 0179 


4.63 


4.71 


I .0244 


6. 29 


6.44 


1 .0050 


1-31 


1-32 


i.oiis 


2.97 


3- 00 


I .0180 


4.66 


4-74 


1.024s 


6.31 


6.46 


1 .0051 


1.34 


1-35 


I .01 16 


2.99 


3.02 


I .0181 


4.69 


4-77 


I .0246 


6.34 


6.50 


1.0052 


1.36 


1-37 


I .0117 


3.02 


3-o6 


I .0182 


4-71 


4.80 


1.0247 


6.36 


6.52 


I.OOS3 


1.39 


1 .40 


1 .0118 


3-OS 


3-09 


I .0183 


4-74 


4-83 


I .0248 


6.39 


6.SS 


1.0054 


1. 41 


1.42 


I .0119 


3.07 


3" 


I .0184 


4-77 


4.86 


1.0249 


6.41 


6.57 


1.005s 


1.44 


1. 45 


I .0120 


310 


3-14 


I .0185 


4-79 


4. 88 


1.0250 


6.44 


6.60 


1.0056 


1 .46 


1.47 


I .0121 


3-12 


3.16 


1.0186 


4.82 


4.5. 


I .0251 


6.47 


6.63 


I.OOS7 


1.49 


I. SO 


I .0122 


3. IS 


319 


I .0187 


4-8s 


4-94 


1.0252 


6. 50 


6.66 


1.0058 


I. 51 


1-52 


I .0123 


3-17 


3.21 


I. 0188 


4. 88 


4-97 


I-0253 


6.52 


6.68 


1. 0059 


1-54 


1-55 


I. 0124 


3.20 


3.24 


I .0189 


4.90 


4.99 


1.0254 


6.SS 


6.72 


1.0060 


i.S6 


1.S7 


1.0I2S 


3-23 


3.27 


I .0190 


4-93 


5.02 


1.0255 


6.58 


6. 75 


I. 0061 


1-59 


1.60 


I .0126 


3-25 


3.29 


I .0191 


4.96 


5.05 


1.0256 


6.61 


6.78 


1.0062 


1 .62 


1.63 


I .0127 


3.28 


3-32 


I .0192 


4.98 


5.0S 


1.0257 


6.63 


6.80 


1.0063 


1 .64 


1.65 


I .0128 


3.30 


3-34 


I. 0193 


5-OI 


5. II 


1.0258 


6.66 


6.83 


1.0064 


1.67 


1.68 


I .0129 


3-33 


3-37 


I. 0194 


S-04 


S.I4 


I.02S9 


6.69 


6.86 



Calculated from results obtained bv drvine below 75° C. 



750 



FOOD INSPECTION AND ANALYSIS. 



EXTRACT IN BEER WORT— {Continued). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 












. 




s 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Pe? 


Grams 

per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 1 5° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
1 00 cc. 


at 15° C. 


Cent 

by 

Weight 


I .0260 


6.71 


6.88 


1.032s 


8.27 


8.S4 


1.0390 


9-92 


10.31 


I -0455 


11.53 


12.0s 


I .026X 


6.74 


6.92 


1.0326 


8.29 


8.56 


1.0391 


9-95 


10.34 


1.0456 


ii-SS 


12.08 


1 .0262 


6-77 


6.95 


1-0327 


8.32 


8.59 


1.0392 


9-97 


10.36 


1-0457 


11.57 


12. 10 


1.0263 


6.80 


6.98 


I .0328 


8.34 


8.61 


1.0393 


9-99 


10.38 


1-0458 


II .60 


12.13 


I .0264 


6.82 


7 .00 


1.0329 


8.37 


8.65 


1.0394 


10.02 


10 .41 


1-0459 


11.62 


12.15 


I .0265 


6.8s 


7-03 


1.0330 


8.40 


8.68 


1-0395 


10. 04 


10.44 


1 .0460 


11.6s 


12.19 


1.0266 


6.88 


7.06 


I. 0331 


8-43 


8.71 


1.0396 


10.06 


10.46 


I .0461 


11.67 


12.21 


1 .0267 


6.91 


7.09 


1-0332 


8.4s 


8-73 


1.0397 


10.00 


10.49 


I . 0462 


11.70 


12.24 


1.0268 


6.93 


7.12 


1-0333 


8.48 


8.76 


1.0398 


10.11 


10.51 


1.0463 


11.72 


12. 26 


1 .0269 


6.96 


7-iS 


1.0334 


8.51 


8-79 


1.0399 


10. 13 


10. S3 


I .0464 


11-75 


12.30 


1 .0270 


6 99 


7.18 


1-0335 


8. S3 


8.82 


I . 0400 


10.16 


10.57 


1.046s 


11.77 


12.32 


I .0271 


7.01 


7 . 20 


1-0336 


8.56 


8.85 


I .0401 


10.18 


10.59 


I .0466 


11.79 


12.34 


1 .0272 


7.04 


7-23 


1.0337 


8.59 


8.88 


I .0402 


10. 20 


10. 61 


1.0467 


11.82 


12.37 


1.0273 


7.07 


7 . 26 


1.0338 


8.61 


8.90 


I .0403 


10.23 


10. 64 


1.0468 


11.84 


12.39 


1.0274 


7.10 


7.29 


1.0339 


8.64 


8.93 


I .0404 


10. 25 


10.66 


I .0469 


II. 87 


12.43 


I. 027s 


7-12 


7-32 


I .0340 


8.67 


8.96 


1.0405 


10. 27 


10.69 


1.0470 


11.89 


I 2.4s 


1 .0276 


7-15 


7-35 


1.0341 


8.70 


9.00 


I .0406 


10.30 


10. 7^ 


1.0471 


11.92 


12.48 


1.0277 


7.18 


7.38 


1.0342 


8.72 


9. 02 


I . 0407 


10.32 


10.74 


1.0472 


11.94 


12.50 


I .0278 


7.21 


7.41 


1.0343 


8.75 


9-05 


I .0408 


10.35 


10.77 


1-0473 


11.97 


12.54 


I .0279 


7-23 


7.43 


1.0344 


8.78 


9.08 


I .0409 


10.37 


10.79 


1.0474 


11.99 


12.56 


I .0280 


7.26 


7.46 


I -0345 


8.80 


9. 10 


I . 0410 


10.40 


10.83 


1-0475 


12.01 


12.58 


I .0281 


7.28 


7.48 


I -0346 


8.83 


9.14 


1 .041 1 


10.42 


10. 8s 


1.0476 


I 2 . 04 


12.61 


1 .0282 


7-3° 


7-51 


1-0347 


8.86 


9.17 


1 .0412 


10.45 


10. 88 


1.0477 


12 .06 


12. 64 


I .0283 


7-33 


7-54 


1.0348 


8.88 


9.19 


1.0413 


10.47 


10.90 


1.0478 


1 2 .09 


12.67 


I .0284 


7-3S 


7-S6 


1.0349 


8.91 


9. 22 


I .0414 


10.50 


10.93 


1.0479 


12.11 


I 2. 69 


1.028s 


7-37 


7-58 


1.0350 


8.94 


9-25 


I. 0415 


10.52 


10.96 


1 .0480 


12.14 


12.72 


1.0286 


7-39 


7.60 


I -0351 


8.97 


9.28 


I .0416 


10.55 


10.99 


I .0481 


12.16 


12.74 


1.0287 


7-42 


7.63 


1-0352 


8.99 


9-31 


1.0417 


10.57 


II .01 


I .0482 


12.19 


12.78 


1.0288 


7-44 


7-6s 


1-0353 


9.02 


9-34 


I .0418 


10. 60 


1 1 .04 


1.04S3 


12.21 


12.80 


1.0289 


7.46 


7.68 


1-0354 


9-os 


9-37 


I .0419 


10.62 


II .06 


1 . 0484 


12.23 


12. Sa 


1 .0290 


7.48 


7.70 


I-0355 


9.07 


9-39 


1 .0420 


10.65 


II . lO 


1.0485 


12.2(3 


12.8s 


I .0291 


7-51 


7-73 


1.0356 


9. 10 


9-42 


I .0421 


10.67 


11.12 


1.0486 


12.28 


12.88 


1 .0292 


7-53 


7.75 


1-0357 


9-13 


9-46 


I .0422 


10. 70 


II. 15 


1.0487 


12.31 


12.91 


1.0293 


7.55 


7-77 


I 0358 


9-15 


9-48 


I.04«3 


10.72 


11.17 


1.0488 


12.33 


12.93 


I .0294 


7-57 


7-79 


1-0359 


9.18 


9. SI 


1.0424 


10.75 


11.21 


I .0489 


12.36 


12.96 


1.029s 


7 .60 


7.82 


I .0360 


9. 21 


9-54 


1.0425 


10.77 


11.23 


1 .0490 


12.38 


12.99 


1 .0296 


7.62 


7.8s 


I. 0361 


9.24 


9-57 


I .0426 


TO. So 


11 . 26 


1.0491 


12.41 


13.02 


I .0297 


7.64 


7-87 


1.0362 


9. 26 


9.60 


1.0427 


10.82 


11.28 


1.0492 


12.43 


13-04 


I .0298 


7.66 


7-89 


1-0363 


9-29 


9-63 


I .0428 


10.85 


II. 31 


1.0493 


12.45 


13-06 


I .0299 


7.69 


7.92 


1.0364 


9-31 


9-65 


I .0429 


10.88 


11-35 


1.0494 


12.48 


13.10 


1 .0300 


7.71 


7-94 


1.0365 


9-34 


9-68 


1.0430 


10. 90 


11.37 


I. 049s 


12.50 


13-13 


1.0301 


7.73 


7.96 


I .0366 


9-36 


9.70 


1.0431 


10.93 


II .40 


I . 0496 


12.53 


13.15 


1.0302 


7-75 


7-98 


1.03.67 


9-38 


9-72 


1.0432 


10.95 


11.42 


1.0497 


12.55 


13.17 


1 .0303 


7.77 


8.01 


1.0368 


9.41 


9-76 


1.0433 


10.98 


II .46 


1 . 0498 


12.58 


13-21 


1 .0304 


7.80 


8.04 


I .0369 


9-43 


9-78 


1-0434 


1 1 .00 


11.48 


I .0499 


12 . 60 


13.23 


1.030s 


7.82 


■ 8.06 


1.0370 


9-45 


9.80 


I -0435 


II .03 


II. 51 


I .0500 


12.63 


13. 26 


1.0306 


7.84 


8.06 


1-0371 


9.48 


9.83 


1 .04:36 


II .01; 


II .53 


I .0501 


I 2 . 6.5 


13.28 


1.0307 


7.86 


8.10 


1.0372 


9-50 


9.85 


1-0437 


11.08 


11.56 


1 .0502 


I 2 . 67 


13-31 


1.0308 


7.89 


8.13 


1-0373 


9-52 


9.88 


I .0438 


11.10 


11.59 


1.0503 


12 .70 


13-34 


1 .0309 


7.91 


8. IS 


1-0374 


9-55 


9.91 


1-0439 


II. 13 


11.62 


1.0504 


12.72 


13-36 


I .0310 


7-93 


8.1S 


1-0375 


9-57 


9-93 


1 .0440 


II. IS 


1 1 . 64 


I. 050s 


12.75 


13-39 


I .0311 


7-9S 


8.20 


1-0376 


9-59 


9-95 


I .0441 


II. 18 


11.67 


I .0506 


12.77 


13.42 


1.0312 


7.98 


8.23 


1-0377 


9.62 


9.98 


I. 0444 


11 . 20 


11.70 


1.0507 


12.80 


13-45 


I-°3I3 


8.00 


8.25 


1.0378 


9-64 


10.00 


1.0443 


11-23 


11-73 


1.0508 


12.82 


13-4*/ 


1. 0314 


8.02 


8.27 


1-0379 


9.66 


10.03 


1.0444 


II. 2S 


11-75 


1.0509 


12.8s 


13.50 


1-0315 


8.04 


8.29 


I .0380 


9.69 


10.06 


1.0445 


1 1 . 2S 


11.78 


1. 0510 


12.87 


13-53 


1.0316 


8.07 


8.33 


1 .0381 


9.71 


10.08 


I .0446 


11.30 


11.80 


1 .051 1 


I 2 .90 


13-56 


1.0317 


8.09 


8-35 


I .0382 


9-73 


10. 10 


1.0447 


II -33 


11.84 


1 .05 1 2 


12.92 


13.58 


1.0318 


8. II 


8.37 


1-0383 


9-76 


10. 13 


I .0448 


11-35 


11.80 


1.0513 


12.94 


13-60 


I.0319 


8.13 


8.39 


I .0384 


9.78 


10. 16 


1.0449 


II ?8 


11.89 


1.0514 


12.97 


13-64 


I .0320 


8.16 


8.42 


1.038s 


9.81 


10. 19 


I .0450 


II .40 


11.91 


1-0515 


12.99 


13-66 


I.O321 


8.18 


8.44 


I .0386 


9 83 


10.21 


I .0451 


11-43 


11.95 


1.0516 


13.02 


13-69 


1. 0322 


8.20 


8.46 


1.0387 


9-85 


10.23 


1.0452 


11-45 


11.97 


1.0517 


13.04 


13.71 


1-0323 


8.22 


8.49 


I .0388 


9.88 


10. 26 


1-0453 


11.48 


1 2 .00 


1.0518 


13-07 


13-75 


1.0324 


8.2s 
1 


8.52 


1.0389 


9.90 


10. 29 


1.0454 


11.50 


I 2.02 


1.0519 


13-09 


13.77 



ALCOHOLIC BEVERAGES. 



751 



EXTRACT IN BEER WORT— iCotiltmied). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 
at is° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C. 


Per 

Cent 

by 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C 


Per 

Cent 

bv 

Weight 


Grams 

per 
100 cc. 


Gravity 
at 15° C 


Per 
Cent 

bv 
Weight 


Grams 

per 
100 cc. 


I .0520 


13-12 


13.80 


i.os8=; 


14-75 


15.61 


1 .0650 


16. 25 


17-31 


1.0715 


17.81 


19. 08 


1 .0521 


13.14 


13.82 


1.05S6 


1-^ 78 


15.65 


1 -0651 


16.27 


17-33 


1 .0716 


17.84 


19.12 


r . 0522 


i3-i6 


13-85 


I .0587 


14.81 


15.68 


1.0652 


16. 30 


17.36 


1.0717 


17.86 


19.14 


T .0523 


13.19 


13-88 


1.0588 


14.83 


15.70 


1.0653 


16.32 


17-39 


1 .0718 


17.88 


19.16 


I .0524 


13.21 


13-90 


1-0589 


14.86 


15.74 


1.0654 


16.35 


17.42 


1.0719 


17.90 


19.19 


1.0525 


13.24 


13-94 


I .0590 


14.89 


15-77 


1-065S 


16.37 


17.44 


1 .0720 


17.93 


19.22 


I .0526 


13.26 


13-96 


1.0591 


14.91 


15.79 


I .0656 


16.40 


17-4S 


I . 0721 


17.95 


19.24 


I 0527 


13 29 


13-99 


1.0592 


14.94 


15-82 


1.0657 


16.42 


17-50 


I .0722 


17.97 


19. 27 


I .0528 


13.31 


14.01 


1-0593 


14:96 


15.85 


1.0658 


16.45 


17-53 


I .0723 


17 .99 


19. 29 


1.0529 


13.34 


14.05 


I. 0594 


14.99 


15.88 


I .0659 


16.47 


17-56 


1.0724 


18.02 


19.32 


1.0530 


13.36 


14.07 


I-059S 


15.02 


IS. 91 


I .0660 


16.50 


17-59 


1.0725 


18.04 


19.3s 


1.0531 


13.38 


14.09 


I -0596 


15.04 


15.94 


1 .0661 


16.52 


17.61 


1 .0726 


18.06 


19.37 


I .0532 


13.41 


14. 12 


I-OS97 


15.07 


15.97 


1 .0662 


16.54 


17-63 


1.0727 


18.08 


19.39 


I.0533 


13-43 


14. IS 


1 .0598 


15.09 


I 5 - 99 


I .0663 


16.57 


17-67 


1 .0728 


18.11 


19 .43 


1.0534 


13.46 


14.18 


1.0599 


I5-II 


16.02 


1 .0664 


16.59 


17-69 


1 .0729 


18.13 


19.4s 


I. 053s 


13.48 


14. 20 


1 .0600 


15.14 


16.05 


I .0665 


16.62 


17-73 


1.0730 


18.15 


19.47 


1.0536 


13. SI 


14-23 


1 .0601 


15. 16 


16.07 


1.0666 


16. 64 


17-75 


1.0731 


18.17 


19. 50 


I.OS37 


13.53 


14.26 


1 .0602 


15. 18 


16. 09 


I .0667 


16.67 


17.78 


1.0732 


18.20 


19.53 


1.0538 


13.56 


14.29 


1 .0603 


15.20 


16.12 


1.0668 


16.69 


17.80 


1.0733 


18.22 


19 55 


I.0539 


13-58 


14.31 


I 0604 


15 23 


16 15 


1 0669 


16.72 


17-84 


1.0734 


18.24 


19.58 


I .0540 


13.61 


14-34 


1 .0605 


15.25 


16.17 


I .0670 


16.74 


17.86 


1.073s 


18.26 


19.60 


I. 0541 


13.63 


14-37 


1 .0606 


15.27 


16. 20 


I .0671 


16.76 


17-88 


1.0736 


18.29 


19.64 


1.0542 


13.66 


14.40 


I .0607 


15.29 


16. 22 


1 .0672 


16.79 


17.92 


1.0737 


18.31 


19. 66 


t.0543 


13.68 


14.42 


1 .0608 


15.31 


16. 24 


1.0673 


16.81 


17.94 


1.0738 


18.33 


19.68 


I -0544 


13.71 


14.46 


I .0609 


15.34 


16.27 


I .0674 


16.84 


17-98 


1.0739 


18.3s 


19.71 


1.054s 


13.73 


14.48 


I .0610 


15.36 


16.30 


1.0675 


16.86 


18.00 


1.0740 


18.38 


19 . 74 


1.0546 


13.76 


14-51 


1 .0611 


15.38 


16.32 


1 .0676 


16.89 


18.03 


1 .0741 


18.40 


19 ■ 76 


I -0547 


13.78 


14-53 


1 .061 2 


15.40 


16.34 


1 .0677 


16.91 


18.05 


1.0742 


18.42 


19.79 


1.0548 


13-81 


14-57 


1 .0613 


15.43 


16.38 


1.0678 


16.94 


18.09 


1.0743 


18.44 


19.81 


I.OS49 


13-83 


14-59 


I . 0614 


15.45 


16 .40 


1 .0679 


16.96 


18.11 


1.0744 


18-47 


19.84 


1.0550 


13-86 


14. 62 


1 .0615 


15.47 


16.42 


I .0680 


16.99 


18.15 


1.074s 


18.49 


19.87 


I. 0551 


13-88 


14.64 


1 .0616 


15.49 


16.44 


1 .06S1 


17.01 


18.17 


1 .0746 


18.51 


19 . 89 


1.0552 


13-91 


14.68 


1 .0617 


15.52 


16.48 


1.0682 


17.03 


18.19 


1.0747 


18-53 


19.91 


I.05S3 


13-93 


14-70 


1 .0618 


15.54 


16. 50 


1.0683 


17 .06 


18.23 


I -0748 


18.5s 


19.94 


1.0554 


13.96 


14-73 


I .0619 


15.56 


16.52 


1 .0684 


17.08 


18.25 


1.0749 


18.57 


19. 96 


1.055s 


13-98 


14-76 


1 .0620 


15.58 


16.55 


1.0685 


17.11 


18.28 


I .0750 


18.59 


19.98 


1.0556 


14.01 


14-79 


1 .0621 


15.60 


16.57 


I .06S6 


17.13 


18.31 


1.0751 


18.62 


20 .02 


I.OS57 


14-03 


14.81 


I .0622 


15.63 


16. 60 


1.0687 


17.16 


18.34 


1.0752 


18.64 


20 .04 


1.0558 


14.06 


14.84 


I .0623 


15-65 


16.62 


1.06S8 


17-18 


18.36 


I .0753 


18.66 


20 . 07 


I-OSS9 


14.08 


14.87 


I . 0624 


15.67 


16. 64 


1 .0689 


17.21 


18.40 


I.07S4 


18.68 


20.09 


I .0560 


14. 11 


14.90 


I .0625 


15.69 


16.66 


1 .0690 


17.23 


18.42 


1.0755 


18.70 


20. II 


1.0561 


14-13 


14.92 


1 .0626 


15.72 


16. 70 


1 -o6gi 


17.25 


18.44 


1.0756 


18.72 


20. 14 


I .0562 


14. 16 


14.96 


1 .0627 


15.74 


16.73 


1 .0692 


17.28 


18.48 


1.0757 


18.74 


20. 16 


1-0563 


14.18 


14.98 


I .0628 


15.76 


16.7s 


1.0693 


17.30 


18.50 


1.0758 


18.76 


20.18 


1.0564 


14. 21 


15-01 


1 .0629 


15.78 


16.77 


I .0694 


17.33 


18. S3 


1.0759 


18.78 


20. 21 


1-0565 


14-23 


15.03 


I .0630 


15.80 


1 6. So 


I .0695 


17.35 


18.56 
18.59 


I .0760 


18.81 


20 . 24 


r.0566 


14. 26 


15.07 


1.0631 


15.83 


16.83 


I .0696 


17.38 


I .0761 


18.83 


20. 26 


1.0567 


14.28 


15.09 


1-0632 


15.85 


16.85 


I .0697 


17.40 


18.61 


1 .0762 


18.85 


20. 29 


1.0568 


14-31 


15.12 


1-0633 


15.87 


16.87 


1 .0698 


17.43 


18.65 


1.0763 


18.87 


20 . 31 


1.0569 


14.33 


15.15 


1-0O34 


15-89 


16.90 


I .0699 


17.45 


18.67 


I .0764 


18.89 


20.33 


1.0570 


14.36 


15.18 


1-0635 


15.92 


16.93 


1 .0700 


17-48 


18.70 


1.0765 


18.91 


20. 36 


I. 0571 


14.38 


IS . 20 


1.0636 


15.94 


16.95 


1 .0701 


17-50 


18.73 


1 .0766 


18.93 


20.38 


1.0572 


14.41 


15.23 


1.0637 


15.96 


16.98 


1 .0702 


17-52 


18.75 


1-0767 


18.95 


20.40 


I.0573 


14.44 


I-S.27 


1 .0638 


15-98 


1 7 .00 


1-0703 


17-54 


18.77 


1.0768 


18-97 


20.43 


I.OS74 


14.46 


15-29 


1.0639 


16.01 


17.03 


1 . 0704 


17-57 


18.81 


I .0769 


19.00 


20.46 


1.057s 


14.49 


15.32 


1 .0640 


16.03 


17.06 


1.0705 


17-59 


.18.83 


1.0770 


19.02 


20.48 


x.=576 


14.52 


15.36 


1 .0641 


16.05 


17.08 


1 .0706 


17.61 


18.85 


1-0771 


19.04 


20. 51 


1.0577 


14-54 


15.38 


1 .0642 


16.07 


17.10 


1-0707 


17.63 


18.88 


1.0772 


19. 06 


20. 53 


1.0578 


14.57 


15.41 


I .0643 


16.09 


17.12 


I .0708 


17-66 


18.91 


1-0773 


19.08 


20.5s 


I. 0579 


14-59 


15.43 


I .0644 


16.12 


17.16 


1 .0709 


17-68 


18.93 


1.0774 


19. 10 


20.58 


I .0580 


14. 62 


15.47 


I .0645 


16.14 


17-18 


I .0710 


17.70 


18.96 


1.077s 


19.12 


20.60 


1.0581 


14.65 


15-S0 


I .0646 


16.16 


17 . 20 


1.0711 


17.72 


18.98 


1-0776 


19. 14 


20. 63 


I .0584 


14-67 


15.52 


I .0647 


16.18 


17.23 


I .0712 


17-75 


19.01 


1-0777 


19.17 


20.66 


1.0583 


14.70 


15-56 


I .0648 


16.21 


17.26 


I. 0713 


17-77 


19.04 


1.0778 


19.19 


20.68 


I .0584 


14.73 


15-59 


5- 0649 


16.23 


17.28 


1.0714 


17.79 


19.06 


1.0779 


19. 21 


20.71 



752 



FOOD INSPECTION AND ANALYSIS. 



EXTRACT IN BEER YJOWT—{Contimied). 





Extract. 


Specific 


Extract. 


Specific 


E.xtract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Gr9,ms 


Gravity 


Per 


Grams 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


I .0780 


19-23 


20.73 


1.0845 


20. 70 


22.45 


I .0910 


22.19 


24. 21 


1.0975 


23.59 


25.89 


I .0781 


19.25 


20.75 


I .0846 


20.73 


22.48 


I .0911 


22. 21 


24.24 


I .0976 


23.61 


25.92 


I .0782 


19.27 


20.78 


I .0847 


20.75 


22.50 


I .0912 


22.23 


24. 26 


1.0977 


23.63 


2594 


1.0783 


19.29 


20.80 


1.0848 


20.77 


22.53 


I. 0913 


22. 26 


24.29 


I .0978 


23.65 


25-97 


I .0784 


19-31 


20.82 


1 .0849 


20.79 


22.55 


I . 0914 


22.28 


24-31 


1.0979 


23.67 


25-99 


1.078s 


19-33 


20.85 


I .0850 


to. 81 


22.58 


1.091S 


22.30 


24-34 


I .0980 


23.69 


26.01 


1.0786 


19.36 


20.88 


1.0S51 


20.83 


22. 61 


I .0916 


22.32 


24-37 


I .0981 


23.71 


26.04 


1.0787 


19-38 


20.90 


I .0852 


20.86 


22 .64 


I. 0917 


22.34 


24-39 


I .0982 


23-73 


26.06 


t.0788 


19.40 


20.93 


I .0853 


20.88 


22 .66 


I .0918 


22.37 


24.42 


I .0983 


23.76 


26.09 


t .0789 


19.42 


20.95 


1.0854 


20.90 


22.68 


I .0919 


22.39 


24-44 


I .0984 


23.78 


26.11 


I .0790 


19.44 


20. 98 


1.0855 


20.93 


22.72 


1 .0920 


22.41 


24.47 


I .0985 


23.80 


26. 14 


1.0791 


19.46 


21 .00 


1.0856 


20.95 


22.75 


1 .0921 


22.43 


24.49 


I .0986 


23.82 


26. 17 


1.0792 


19.49 


21 .03 


1.0857 


20.98 


22.78 


I .0922 


22.45 


24.51 


I .0987 


23.84 


26. 19 


I .0793 


19-51 


21 .06 


1.0858 


21 .01 


22.81 


1.0923 


22 48 


24-54 


1.0988 


23.86 


26.22 


1.0794 


19-53 


21.08 


1.0859 


21 .04 


22.84 


I .0924 


22.50 


24-56 


I .0989 


23.88 


26. 24 


».079S 


19-56 


21.11 


1.0860 


21 .06 


22.87 


1.0925 


22.52 


24.60 


I .0990 


23.90 


26.27 


1 .0796 


19-58 


21 . 14 


I. 0861 


21 .09 


22.90 


I .0926 


22.54 


24.62 


I .0991 


23.92 


26.30 


1.0797 


19.60 


21 . 16 


1 .0862 


21 . II 


22.93 


1.0927 


22.56 


24.64 


I .0992 


23.94 


26.32 


1 .0798 


19.63 


21 . 20 


1.0863 


21.13 


22.96 


I .0928 


22.59 


24.67 


I .0993 


23-97 


26.35 


1.0799 


19.65 


21 . 22 


1 .0864 


21.16 


22.99 


I .0929 


22 .61 


24.70 


1.0994 


23-99 


26.37 


1 .0800 


19.67 


21 . 24 


1.0865 


21 . 19 


23.02 


1.0930 


22.63 


24-73 


1.0995 


24.01 


26.40 


1 .0801 


19.70 


21.28 


1.0866 


21.22 


23.06 


I. 0931 


22 . 65 


24-76 


I .0996 


24.03 


26.42 


1 .0802 


19.72 


21.30 


1.0867 


21 .25 


23.09 


1.0932 


22. 67 


24-78 


1.0997 


24.05 


26.44 


1.0803 


19.74 


21.33 


1.0868 


21.28 


23.12 


1.0933 


22. 69 


24.81 


I .0998 


24.07 


26.47 


1 .0804 


19.77 


21 .36 


I .0869 


21.30 


23-IS 


1.0934 


22.71 


24-83 


1.0999 


24.09 


26.49 


I .0805 


19.79 


21.38 


1 .0870 


21.33 


23.18 


1.0935 


22.73 


24.86 


1 . 1000 


24. II 


26.52 


I .0806 


19-81 


21 .41 


I. 0871 


21.35 


23.21 


1.0936 


22.75 


24.89 


I . lOOI 


24-13 


26.5s 


I .0807 


19-84 


21.43 


I .0872 


21.37 


23.23 


1-0937 


22.77 


24.91 


I . 1002 


24-15 


26.57 


1.0808 


19.86 


21 .46 


1.0873 


21.39 


23. 26 


1.0938 


22.80 


24-93 


I .1003 


24.17 


26.60 


I .0809 


19.88 


21.49 


1.0874 


21 .41 


23.28 


I .0939 


22.82 


24-96 


I . 1004 


24.19 


26 . 62 


I .0810 


19-91 


21 .52 


1.0875 


21.43 


23-31 


I .0940 


22.84 


24.99 


1 . 1005 


24. 21 


26.6s 


1 .0811 


19-93 


21.55 


1.0876 


21.45 


23-33 


I .0941 


22.86 


25.01 


I . 1006 


24.23 


26.68 


I .0812 


19.96 


21.58 


1.0877 


21.47 


23-36 


I .0942 


22.88 


25.03 


I . 1007 


24.25 


26.70 


I. 0813 


ig-98 


21 .60 


1.0878 


21.49 


23-38 


1.0943 


22.90 


25.06 


I . 1008 


24.28 


26.73 


1 .0814 


20.00 


21 .63 


1 .0879 


21.51 


23-40 


1.0944 


22.92 


25.08 


I . 1009 


24.30 


26.75 


1.081S 


20.03 


21 .66 


1.0880 


21.54 


23-43 


1.0945 


22.94 


25.11 


I . lOIO 


24.32 


26.78 


1.0816 


20.05 


21 .69 


I. 0881 


21 .56 


23-45 


I .0946 


22 .96 


25- 14 


I . lOI I 


24-34 


26.81 


1. 0817 


20.07 


21.71 


1.08S2 


21.58 


23.48 


1.0947 


22.98 


25.16 


I . lOI 2 


24. 36 


26.83 


1.0818 


20 . 10 


21.74 


I .0883 


21 . 60 


23-50 


I .0948 


23.00 


25.18 


I.IOI3 


24-39 


26.86 


I .0819 


20. 12 


21.77 


1.0884 


21 .62 


23-52 


1.0949 


23.03 


25.21 


1 . IOI4 


24.41 


26.88 


1 .0820 


20. 14 


21 .79 


1.0885 


21 . 64 


23-55 


I .0950 


23.05 


25.24 


I.IOI5 


24.43 


26.91 


I .0821 


20. 17 


21.83 


1.0886 


21 . 66 


23-58 


I. 0951 


23.07 


25.26 


I . IO16 


24-45 


26.93 


1 .0822 


20. ig 


21.85 


1.0887 


21.68 


23.60 


1.0952 


23.10 


25.29 


I . IOI7 


24-47 


26.95 


1 .0823 


20 . 21 


21.87 


1.0888 


21.71 


23.63 


1-0953 


23.12 


25.31 


I . IO18 


24.49 


26.98 


1 .0824 


20. 24 


21.91 


1.0889 


21.73 


23.66 


1-0954 


23-14 


25.34 


I . IOI9 


24-51 


27 .00 


1.0825 


20. 26 


21 .93 


1 .0890 


21.75 


23.69 


I-095S 


23-16 


25-37 


I . 1020 


24-53 


27-03 


1.0826 


20.28 


21 .96 


1 .0891 


21.77 


23.72 


1.0956 


23.18 


25-39 


1 . I02I 


24-55 


27 -06 


1.0827 


20.31 


21.99 


I .0892 


21.79 


23-74 


1.0957 


23.20 


25-42 


1 . 1022 


24-57 


27.08 


1.0828 


20.33 


22.01 


I .0893 


21.82 


23-77 


1.0958 


23.23 


25.45 


I. 1023 


24. 60 


27.11 


I .0829 


20.35 


22 . 04 


I .0894 


21.84 


23-79 


I .0959 


23.25 


25.47 


1 . 1024 


24. 62 


27.14 


1.0830 


20.37 


22.06 


1.0895 


21.86 


23.82 


I .0960 


23.27 


25.50 


1.I02S 


24.64 


27.17 


I .0831 


20.39 


22.08 


I .0896 


21.89 


23.85 


I .0961 


23.29 


25.53 


1 . 1026 


24. 66 


27.19 


I .0832 


20.41 


22.11 


i.o8)7 


21.91 


23.87 


I .0962 


23.31 


25.55 


I . 1027 


24.68 


27. 21 


1.0833 


20.43 


22.13 


1.0898 


21.93 


23.90 


1.0963 


23.33 


25-58 


I . 1028 


24.70 


27.24 


1.0834 


20.46 


22. 16 


I .0899 


21 . 96 


23-93 


I .09O4 


23.35 


25.60 


I . 1029 


24.72 


27 . 26 


1.0835 


20.48 


22. 19 


I .0900 


21.98 


23.96 


I .0965 


23-37 


25.63 


1.1030 


24.74 


27.29 


1.0836 


20.50 


22.21 


I .0901 


22 .00 


23.98 


I .0966 


23-39 


25.66 


I.IO31 


24.76 


27.32 


1.0837 


20.52 


22. 24 


I .0902 


22.02 


24.01 


I .0967 


23-41 


25.68 


1.1032 


24.78 


27.34 


1.0838 


20.54 


22. 26 


1 .0903 


22 .04 


24-03 


I .0968 


23.44 


25.71 


1.1033 


24.81 


27.37 


1.0839 


20.56 


22. 29 


1 .0904 


22.06 


24.05 


1 .0969 


23.46 


25.73 


1.1034 


24.83 


27.39 


1 .0840 


20.59 


22.32 


I .0905 


22.08 


24.08 


1 .0970 


23.48 


25.76 


1.1035 


24.85 


27.42 


1 .0841 


20 . 62 


22.35 


I .0906 


22.10 


24. II 


I. 0971 


23-50 


25.79 


I . 1036 


24.87 


27.45 


1 .0842 


20.64 


22.38 


I .0907 


22.12 


24-13 


I .0972 


23.52 


25.81 


I.I037 


24.89 


27.47 


1.0843 


20. 66 


22 .40 


1 .0908 


22.15 


24. 16 


1-0973 


23.5s 


25.84 


1.1038 


24.92 


27.50 


1,0844 


20.68 


22.42 


I .0009 


22.17 


24.18 


1.0974 


23-57 


25.86 


1 1039 


24.94 


27-S3 



I 



ALCOHOLIC BEVERAGES. 



753 



EXTRACT IN BEER ^ORT— {Concluded). 





Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


Extract. 


Specific 


















Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


Gravity 


Per 


Grams 


at I s° C. 


Cent 

bv 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 

Weight 


per 
100 cc. 


at 15° C. 


Cent 

by 
Weight 


per 
100 cc. 


1 . 1040 


24.96 


27.56 


I. 1095 


26. 16 


29.03 


1.1150 


27.29 


30.43 


1 . 1 205 


28.38 


31-81 


t . 1041 


24.98 


27.58 


I . 1096 


26.18 


29 .06 


1.1151 


27.31 


30.45 


1 . 1206 


28.40 


31 83 


1 . 1042 


2S .00 


27 .60 


I. 1097 


26. 20 


29.08 


1 . 1 1 5 2 


27-33 


30.47 


1 . 1 207 


28.42 


31-86 


I. 1043 


25.03 


27.63 


I . 1098 


26.23 


29. II 


I . 1 1 S 3 


27-35 


30.50 


1. 1 208 


28.44 


31.88 


1. 1044 


25-05 


27 . 66 


I. 1099 


26.25 


29.13 


I.1154 


27-37 


30.52 


I . I 209 


28.46 


31 .00 


1. 1045 


25.07 


27.69 


I . IIOO 


26. 27 


29.16 


1. 1 1 55 


27.38 


30.55 


I . I2t0 


28 . 48 


31.93 


1 . 1046 


25.09 


27.72 


I . IIOI 


26. 29 


29.19 


I. 1156 


27.40 


30.57 


I . I2II 


28.50 


31.9s 


1.1047 


25.11 


27.74 


I . II02 


26.31 


29. 21 


I.II57 


27-42 


30.59 


I . I 21 2 


28.52 


31.98 


I. 1048 


25.14 


27.77 


I.II03 


26.33 


29.24 


1.1158 


27.44 


30.62 


I.I2I3 


28.54 


32.00 


1. 1 049 


25.16 


27.79 


I . I 104 


26.35 


29. 26 


I.IIS9 


27.46 


30.64 


I . I214 


28.56 


32.03 


1. 1050 


25.18 


27.82 


I.IIO5 


26.37 


29.29 


I . 1160 


27.48 


30.67 


I . 1215 


28.58 


32.05 


1.1051 


25 . 20 


27.85 


I . I 106 


26.39 


29.32 


1.1161 


27.50 


30.69 


1 . I216 


28.60 


32.08 


1 . 1052 


25.22 


27.87 


I . II07 


26.41 


29-34 


1.1162 


27-52 


30.72 


I . I217 


28.62 


32.11 


I.IOS3 


25. 24 


27.90 


i.itoS 


26.44 


29-37 


I-I163 


27.54 


30.7s 


I .1218 


28.64 


32.13 


1. 1054 


25.27 


27.93 


1 . 1 109 


26.46 


29.39 


1.1164 


27.56 


30.77 


I . I2I9 


28.66 


32.1s 


I. loss 


25.20 


27.96 


I . IIIO 


26.48 


29-42 


1.116s 


27.58 


30.80 


I . 1220 


28.68 


32.18 


1.10S6 


25.31 


27.98 


1 . 1 1 1 1 


26.50 


29.44 


1.1166 


27 . 60 


30.82 


I . I22I 


28.70 


32. 20 


I.IOS7 


25.33 


28.00 


I . III2 


26.52 


29.46 


1.1167 


27 .62 


30.8s 


I . I 222 


28.72 


32.23 


1. 1058 


25.35 


28.03 


I.III3 


26.54 


29.49 


1.116S 


27.64 


30.87 


I. 1223 


28.74 


32.2s 


I.IOS9 


25.38 


28.06 


1 . 1 1 14 


26.56 


29.51 


1 . 1 169 


27 .66 


30.89 


I . 1224 


28.76 


32.27 


I . 1060 


25.40 


28.09 


1.1115 


26.58 


29-54 


1. 1 1 70 


27. 68 


30.92 


1.1225 


28.78 


32.30 


I .1061 


25.42 


28.12 


1 . 1 1 16 


26. 60 


29-57 


1.1171 


27.70 


30.94 


I . 1226 


28.80 


32.32 


I . 1062 


25.44 


28.14 


1.1117 


26.62 


29.59 


1.1172 


27.72 


30.97 


I . 1227 


28.82 


32.3s 


1. 1063 


25.46 


28.17 


1.1118 


26 . 64 


29. 61 


I-I173 


27-74 


31-00 


I .1228 


28.84 


32.37 


1 . 1064 


25.48 


28.19 


1 . 1 1 19 


26.66 


29.64 


1.1174 


27.76 


31 .02 


I . 1229 


28.86 


32.40 


1.106s 


25.50 


28.22 


1 . 1120 


26.68 


29.67 


1.1175 


27.78 


31.05 


1.1230 


28.88 


32.43 


1 . 1066 


25.52 


28.25 


I . 1121 


26.70 


29.69 


1.1176 


27.80 


31.07 


1.1231 


28.90 


32.4s 


1 . 1067 


25.54 


28.27 


1 . 1 1 22 


26. 72 


29.71 


1.1177 


27.82 


31.09 


1.1232 


28.92 


32.48 


I. 1068 


25.57 


28.30 


1.1123 


26.75 


29.74 


1.1178 


27.84 


31.12 


1.1233 


28.94 


32.50 


1 . 1069 


25.59 


28.32 


1 . 1 1 24 


26.77 


29.77 


I. 1179 


27.86 


31.15 


1.1234 


28.96 


32.53 


1 . 1070 


25.61 


28.35 


1.1125 


26.79 


29.80 


1. 1 1 80 


27.88 


31.18 


1.1235 


28.98 


32.56 


I . 1071 


25.63 


28.38 


1 . 1 126 


26.81 


29.83 


1.1181 


27.90 


31.20 


1.1236 


29.00 


32.58 


1 . 1072 


25.65 


28. 40 


I . 1127 


26.83 


29.85 


1.1182 


27.92 


31.23 


1.1237 


29 . 02 


32.60 


I. 1073 


25.67 


28.43 


1.1128 


26.85 


29.88 


1.1183 


27.94 


31.25 


1.1238 


29.04 


32.63 


1. 1074 


25.69 


28.45 


I . 1129 


26.87 


29.90 


1.1184 


27.96 


31.27 


1.1239 


29. 06 


32.65 


1.107s 


25.71 


28.48 


1.1130 


26.89 


29-93 


1.118s 


27.98 


31.30 


1 . 1240 


29.08 


32.68 


1 . 1076 


25.73 


28.51 


1.1131 


26.91 


29-95 


1.1186 


28.00 


31.32 


1 . 1 241 


29 . 10 


32.71 


1. 1077 


25.75 


28.53 


1.1132 


26.93 


29.97 


1.1187 


28.02 


31.35 


1 . 1242 


29. 12 


32.73 


1 . 1078 


25.78 


28.56 


1.1133 


26.95 


30.00 


1.1188 


28.04 


31.37 


1.1243 


29.14 


32.76 


1. 1079 


25.80 


28.58 


I.II34 


26.97 


30.02 


I.1189 


28.07 


31.40 


1 . 1 244 


29. 16 


32.78 


1 . 1080 


25.82 


28.61 


1.1135 


26.99 


30.06 


I . 1190 


28.09 


31.43 


1.1245 


29.18 


32.81 


I . 1081 


25.84 


28.64 


1.1136 


27.01 


30.08 


1.1191 


28.11 


31.45 


I . 1246 


29. 20 


32.83 


1 . 1082 


25.86 


28.66 


I.II37 


27.03 


30.10 


1.1192 


28.13 


31.48 


1.1247 


29. 22 


32.86 


1. 1083 


25.89 


28.69 


1.1138 


27.05 


30.13 


1.1193 


28. IS 


31.51 


1. 1 248 


29.24 


32.89 


1 . 1084 


25.91 


28.72 


J.1139 


27.07 


30.15 


1.1194 


28.17 


31.53 


1. 1 249 


29. 26 


32.91 


1.108s 


25.93 


28.75 


1 . I 140 


27.09 


30.18 


1.1195 


28.19 


31.56 


1.1250 


29.28 


32.94 


1. 1086 


23.96 


28.78 


I . 1141 


27.11 


30.20 


I . 1 196 


28.21 


31-59 


1.1251 


29.30 


32.96 


1 . 1087 


25.98 


28.80 


I . 1142 


27.13 


30.22 


1.1197 


28.23 


31.61 


I. 1252 


29.32 


32.99 


1. 1088 


26.01 


28.83 


1.1143 


27.15 


30.25 


1.1198 


28.25 


31.63 


I. 1253 


29.34 


33.02 


1 . 1089 


26.03 


28.86 


1.1144 


27.17 


30.27 


1.1199 


28.27 


31.65 


1.I2S4 


29.36 


33-04 


1 .1090 


26.05 


28.89 


1.114s 


27.19 


30.31 


I . 1200 


28.28 


31.68 


1.1255 


29.38 


33-07 


1 . 1091 


26. 07 


28.92 


I . 1146 


27. 21 


30.33 


I . 1201 


28.30 


31.70 


1.1256 


29.40 


33.09 


1 . 1092 


26.09 


28.94 


1. 1 1 47 


27.23 


30.35 


I . 1202 


28.32 


31.73 


1.1257 


29.42 


33.12 


1.1093 


26. 12 


28.97 


1. 1 1 48 


27.25 


30.37 


1.1203 


28.34 


31.75 


1.1258 


29.45 


33.14 


1 . 1094 


26. 14 


29.00 


I. 1149 


27.27 


30.40 


1. 1 204 


23. 36 


31.78 


i.iaS9 


29.47 


33.17 



754 



FOOD INSPECTION AND ANALYSIS. 



Original Gravity of Beer Wort and its Determination. — Following a 
long-established custom of the English excise, the duty on beer has been 
based on the specific gravity of the original wort, by which is meant the 
wort of the beer before any of its sugar has been lost by fermentation. 

From the content of alcohol in the beer the sugar originally present 
in the wort may be calculated, assuming that the alcohol amounts to 
about half the sugar used up in fermentation. 

Obtain the specific gravity of the beer, dealcoholized and made up 
to its original volume, as in the calculation of the extract. This is called 
the " extract gravity." Note the specific gravity corresponding to the 
alcohol found, i.e., the specific gravity of the distillate in the alcohol 
determination, when made up to the original volume, and subtract this 
from I. The difference is known arbitrarily as the "degree of spirit 
indication." 

From the table of Graham, Hofmann, and Redwood,* given below, 
the "degrees of gravity lost" corresponding to the " spirit indication " 
are ascertained. This figure is added to the " extract gravity " to find 
the " original gravity of the wort." 



SUGAR USED UP IN FERMENTATION. 





< . 0000 


0.000 1 


.0002 


. 0003 


.0004 


0.0005 


0.0006 c 


.0007 


0.0008 c 


.0009 


o.ooo 




0.0003 


. 0006 


. 0009 


0.0012 


0.0015 


0.0018 


0021 


0.0024 


.0027 


.001 


.0030 


■0033 


.0037 


.0041 


.0044 


.0048 


.0051 


0055 


.0059 


.0062 


.002 


.0066 


.0070 


.0074 


.0078 


.0082 


.0086 


.0090 


0094 


.9098 


0102 


.003 


.0107 


-OIII 


.0115 


.0120 


.0124 


.0129 


-0133 


0138 


.0142 


0147 


.004 


.0151 


-0155 


.0160 


.0164 


.0168 


.0173 


.0177 


0182 


.0186 


0I9I 


.005 


.0195 


.0199 


.0204 


.0209 


.0213 


.0218 


.0222 


0227 


.0231 


0236 


.006 


.0241 


.0245 


.0250 


-.0255 


.0260 


.0264 


.0269 


0274 


.0278 


0283 


.007 


.0288 


.0292 


.0297 


.0302 


.0307 


.0312 


-0317 


0322 


.0327 


0332 


.008 


-0337 


■0343 


.0348 


-0354 


■0359 


•0365 


.0370 


0375 


.0380 


0386 


.009 


.0391 


-0397 


.0402 


.0407 


.0412 


.0417 


.0422 


0427 


.0432 


0437 


.010 


.0442 


.0447 


.0451 


.0456 


.0460 


.0465 


.0476 


0475 


.04S0 


0485 


-Oil 


.0490 


.0496 


.0501 


.0506 


.0512 


-0517 


.0522 


0527 


-0533 


0558 


.012 


-0543 


.0549 


-^"554 


-0559 


.0564 


.0569 


.0574 


0579 


.0584 


0589 


.013 


-0594 


.0600 


.0605 


.0611 


.0616 


.0622 


.0627 


0633 


.0638 


0643 


.014 


.0648 


.0654 


-0659 


.0665 


.0471 


.0676 


.0682 


0687 


.0693 


0699 


.015 


.0705 


.0711 


.0717 


.0723 


.0729 


-073s 


.0741 


0747 


•0753 


0759 



Report on Original Gravities, 1852; Allen's Coml. Org. Anal., 4 Ed., ^^ol. I, p. 151. 



ALCOHOLIC BEVERAGES. 



755 



Pi 




w 




H 




W 




§ 




o 




H 




U 




< 




Pi 




i^ 




w 




(^ 


* 


^ 


P< 


o 




hH 




C/J 


Pi 


C^ 


w 


w 


w 


§ 


pq 






w 


H 




o 


S 


w 


C H 


Pi 


< 


til 


hJ 




hJ 


Pi 




w 




pp 


p 


!?^ 


W 




ffi 




H 


H 




c; 


Uh 


< 


O 


p< 




H 


« 


X 


^ 


W 


< 




^ 


h 






Pi 


H- 1 


w 

w 

pq 


:? 


W 


< 


ffi 


H 


H 


W 




o 


U< 




O 


(VI 




n 


O 


|j-i 


^ 




1— 1 


pq 


Q 

<: 
w 
Pi 



Ex- 
tract 

in 
loo cc. 
Grams. 




OOOOwwmhm 


t-1 


vooo O rovooo fONO 


t^ 


r^cooooooooooooooo 


CO 


COOOCOOOOOOOOOOOOO 


1 

Qi 





M N (-orj-iovo r^oO O 





H M roTtioO r^cO On 


FEx- 
tract 

in 
loo cc. 
Grams. 






M 


Tf\0 Onm Ttr^OvM T)- 

f^r-r^oooooooo OnOn 


t^ 


i>*t^t^t^r^t^r^t^t^ 


r^ 


r^r^t^r^t^t^t^r^t^ 


Si 
1 




O 


M M ro^io\0 t^oO 0-. 


o 
o 


M M ro-:J-UONO t^OO On 


Ex- 
tract 

in 
loo cc. 
Grams. 




C^C^OOOOwMw 


o 


N lOt^O rOVOOO O tO' 


o 


\00 t^t^t->.t^r^i>.r^ 


t^ 


t^t^t^t^t^r^t^f^r^ 


1 




IN 


H N ro^voo r^co c^ 




00 


H c< co'^vovo r-oo Ov 


Ex- 
tract 

in 
loo cc. 
Grams. 




looo roiOOO M fOO 


00 


M ponO Ovm ^vO Onm 
t^t^t^t-^OOCOOOOO On 


^ 


vOOOOOOOOO 


NO 


nOnOnOnOnOnOnOnOnO 


1 


O 


H M rO'^vovO t^CO On 




no' 


M (N ro^voNO r^cO 0\ 


Extract 

in 
loo cc. 
Grams. 


ON 


■*vO 0\M Tj-t^ONN "*- 
CnO\OnOOOOmm 


t^ 


M 01 M Ol rorOf^f^O"^ 


lO 


ioioij-)mDOnOnOnO^ 


VO 


sOnOnOvOvOnOvovOvO 


1 





M C) rO'+lnvO t^OO O 





M N roTfiovO t^CO On 


Extract 

in 
loo cc. 
Grams. 




•^ 


M irir^o ro^ooO '•O 
-:t-Tl-^lJ-)lOiOiO\OvO 


VO 

NO 


OOMroNOOOHfOvOOv 
NO i^r^J^t^oOCOOOOO 


lO 


LOVOIOVOVOIOLOIOLO 


lO 


lOVOVOVoiOlOVOlOlO 


1 


O 

M 


H N rO'^vOMO t~».c<0 On 


O 


H N rO'+lONO t^OO On 


Extract 

in 
loo cc. 
Grams. 


CO 
00 


M roOCO M -^vO Onm 
CTvOnOnOnO O O O w 


•i- 


t^OvM -ft-~ONN lOI^ 
Mi-iOiriciCNrooOfO 


■* 


■*'^^'^vo\y-)lovoio 


lO 


VolOlOVOlOtOLOVOlO 


1 

1^ 




M 


H « fO-^vnvo r^oo O^ 


O 

d 


H CM rr, Tt- \r> \o t^OO 0-. 


Extract 

in 
loo cc. 
Grams. 


4 


T)-TJ-Tj--:)-lOVOtolr)NO 


NO 


lOOO roloco M rONO 
nOnO r^r^r^t^cOOOoO 


'+-*-*-*'*'^'^'^'* 


^ 


•^■^■^"^^^^■^Tj- 


1 





M M rO'^VOMO t^CO O 




CO 


H M ro-^iovo t^CO On 


Extract 

in 
loo cc. 
Grams. 


vO 


CO w fONOoO w ■+VO 0\ 
CO OnO^OnOnO O O 


:: 


tJ-nO OnN T)-r^OvN 't 
wMMMMMMroco 


ro 


rOrorororO'*^'^^ 


■* 


'+'t'^'*^Tl-^Tl-TS- 


1 


O 

VO 

H 


O 

M 


w c» r^Tl-io>0 t>.00 On 



756 FOOD INSPECTION AND ANALYSIS. 

Example. — Suppose the "extract gravity" is 1.0389 and the specific 
gravity of the alcoholic distillate is 0.9902, both at 15.6. Then i —0.9902 = 
0.0098, the "degree of spirit indication," From the above table the cor- 
responding "degree of gravity lost" is found to be 0.0432. 

0.0432+1.0389 = 1.0821, the original gravity of the w^ort. 

The calculation in the above simplified form is accurate for normal 
beer wherein the free acid present, expressed as acetic, does not exceed 
0.1%. In case of beer that has developed free acid much in excess of 
the above limit, a correction should be added to the degrees of spirit 
indication. This correction, which in practice it is rarely necessary to 
apply except in extreme cases of old or sour beer, is calculated as follows: 

If a represents the grams of free acid (as acetic) in 100 cc, then the 
correction to be added to the spirit indication =0.0013(1 — 0.00014. 

Example. — Supposing the "extract gravity" to be 1.0413, the specific 
gravity of the alcoholic distillate to be 0.9890, and the free acid as acetic 
to be 0.35%. Then 1—0.989=0.0110, the degree of spirit indication. 

0.35X0.0013—0.00014=0.0003, correction to be added to the spirit 
indication. 

0.0110+0.0003 = 0.0113, corrected spirit indication. 

From the above table the corresponding degrees of gravity lost are 

0.0506: 

0.0506+1.0413 = 1.0919, the original gravity of the wort. 

Determination of Degree of Fermentation. — This is calculated by 

200 A 
the formula D = — =r— , in which D = degree of fermentation, A = per cent 
B 

of alcohol by weight, and 5 = the original extract. 

Determination of Reducing Sugars. — Dealcoholize 25 cc. of the beer 
and make up to 100 cc. Determine reducing sugars by the Defren- 
O'Sullivan or Munson-Walker method, and calculate as maltose. 

Determination of Dextrin. — Dilute 50 cc. of the beer to 200 cc, 
hydrolize by heating in a boiling water-bath for 2^ hours with 20 cc. 
of hydrochloric acid (specific gravity 1.125), nearly neutralize the free 
acid with sodium hydroxide, make up to 300 cc, filter, and determine 
the dextrose by copper reduction. Multiply the amount of reducing 
sugars as maltose by 0.95, subtract this from the dextrce, and multiply 
the difference by 0.9, thus obtaining the dextrin in the b:er 

Determination of Glycerol. — Proceed as directed on page 734 under 
wine. The milk of lime is added during evaporation after the carbon 
dioxide has been expelled. It is advisable that the filtrate, after being 



ALCOHOLIC BEVERAGES. 757 

evaporated to a syrupy consistency, be treated again with 5 cc. of 
absolute alcohol and two portions of 7.5 cc. each of absolute ether. 
If clear, continue as directed. If not clear, it is necessary to repeat 
the treatment with lime. 

Determination of Total, Fixed, and Volatile Acids. — A measured 
volume of the beer, say 10 cc, is freed from carbon dioxide by bringing 
to boiling. It is then cooled and titrated with tenth-normal sodium 
hydroxide, using neutral litmus solution as an indicator. Each cubic 
centimeter of tenth-normal alkali is equivalent to 0.009 gram of lactic 
acid, in which the total acidity is usually expressed. 

Fixed acid, also expressed as lactic, though small quantities of suc- 
cinic, tannic, and malic acids are usually also present, is determined as 
follows: Dealcoholize a measured amount of the beer, say 10 cc., by 
evaporation to one-fourth its volume, dilute with water to the original 
volume, and titrate with tenth-normal alkali, as before. 

Volatile acid is expressed as acetic, and is usually calculated by dif- 
ference between total and fixed acid. Each cubic centimeter of tenth- 
normal alkali is the equivalent of 0.006 gram acetic acid. 

Determination of Proteins. — Fifty cc. of the beer are first treated 
with 5 cc. of dilute sulphuric acid, and concentrated by boiling to syrupy 
consistency. Then proceed by the Gunning method, p. 58. Nx6.25 = 
proteins. 

Determination of Phosphoric Acid. — Unless the sample is very dark- 
colored, sufficiently close results can usually be obtained by direct titra- 
tion of the beer itself with uranium acetate solution. For very accurate 
results the ash should be used. Prepare a solution of uranium acetate of 
such strength that 20 cc. will correspond to o.i gram P^Og. This solution 
is best standardized against pure, crystallized, imeffloresced, powdered 
hydrogen sodium phosphate, 10.085 grams of which are dissolved in 
water and made up to a liter. 50 cc. of this solution contains o.i gram 
phosphoric anhydride, if the salt is pure. If the solution is of proper 
strength, 50 cc. evaporated to dryness and ignited in a tared platinum 
dish should have an ash weighing 0.1874 gram. For preliminary trial 
about 35 grams of uranium acetate are dissolved in water, 25 cc. of glacial 
acetic acid, or its equivalent in weaker acid added, and the solution made 
up to a liter with water. 

To standardize, 50 cc. of the standard phosphate solution prepared 
as above are heated to 90° or 100° C, and the uranium solution run in 
from a burette till the resulting precipitate of hydrogen uranium phos- 



758 FOOD INSPECTION AND ANALYSIS. 

plate is complete. The end-point is determined by transferring a few 
drops of the solution to a porcelain plate, and touching with a drop of 
freshly prepared potassium ferrocyanide solution. When the slightest 
excess of uranium acetate has been added, a reddish-brown color is pro- 
duced by the ferrocyanide, The uranium acetate solution is purposely 
made rather stronger than necessary at first, and by repeated trials is 
brought by dilution with water to the required strength (20 cc. equivalent 
to 50 cc. of the phosphate solution). 

Fifty cc. of the beer are heated to 90° or 100° C. and titrated with 
the uranium acetate solution under the same conditions and in precisely 
the same manner as when standardizing that solution. Each cubic centi- 
meter of the uranium acetate corresponds to 0.01% of P2O5. 

For the phosphoric acid determination in the ash, 50 cc. of the beer 
are incinerated in the regular manner, and the ash moistened with con- 
centrated hydrochloric acid. The acid is then evaporated off on the 
water-bath, after which the ash is boiled with 50 cc. of distilled wate^, and 
titrated with the standard uranium solution. 

Determination of Carbon Dioxide.* — In the case of beer and other 
carbonated drinks put up in corked bottles, the carbon dioxide may be 
readily determined by piercing the cork with a metal champagne tap, 
which is connected by a flexible tube, first with a safety flask and then 
with an absorption apparatus somewhat after the style of that used in 
the determination of carbon dioxide in baking powder, the liberated 
carbon dioxide being absorbed for weighing in a concentrated solution 
of potassium hydroxide contained in a tared Liebig bulb. The beer- 
bottle thus connected is immersed in a vessel of water, which is heated 
over a gas-flame, after all the carbon dioxide that will escape spontaneously 
has been allowed to do so. Before weighing the absorbed carbon dioxide, 
the beer-bottle is replaced by a soda-lime tube, and a current of air drawn 
through the tubes. 

Beer and ale put up in bottles having patent metallic or rubber stoppers 
cannot thus be treated. In this case a measured quantity, say 200 cc, 
of the sample is transferred as quickly as possible to a large flask pro- 
vided with an outlet-tube having a glass stopper, this being connected 
up- with the safety-flask and absorp lion-tubes. In this case heat may be 
directly, though cautiously, applied to the flask containing the beer by 
means of a gas-flame, after all the carbon dioxide has gone over that will 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 95; Bui. 107 (rev.), p. 92. 



ALCOHOLIC BEVERAGES. 759 

do so spontaneously. Exactly the same apparatus as that shown in Fig. 
71 may be used to advantage for determination of carbon dioxide m beer, 
except that a larger distilling-flask should be used in the case of beer. 

Detection of Bitter Principles.-Elaborate schemes have been worked 
out for the systematic treatment of beer and ale for bitter principles. Nearly 
all of these are complicated and somewhat unsatisfactory. The presence 
of alkaloids in malt liquors, deliberately introduced during the process 
of manufacture, is now so rare that the analyst need seldom look for them 
except in cases of suspected poisoning, when the scheme of Dragendorf * 
or of Otto-Stas should be employed. While it is somewhat difficult to 
positively identify the various alkaloids, it is usually easy to prove their 
absence in clear solutions, if on treatment with either of the general 
alkaloidal reagents, Mayer's solution, or iodine in potassmm iodide, no 

precipitate is formed. 

It is comparatively easy to prove the mere presence or absence of hop 
substitutes. The bitter principle of hops is readily soluble m ether 
when a sample of the beer evaporated to syrupy consistency is extracted 
therewith while the bitters of quassia and aloes, common hop substitutes, 
are insoluble in ether. Though many varieties of bitters might be em- 
ployed that are soluble in ether, the absence of a bitter taste from the 
ether extract is evidence of the absence of hops. ^ 

The most marked difference analytically between hops and their 
substitutes in malt liquors lies in the fact that the bitter principle of hops 
is completely precipitated therefrom by treatment of the beer with lead 
acetate (either basic or neutral), leaving no bitter taste m the filtrate 
after concentration, while if any of the hop substitutes are present the 
concentrated filtrate from the lead acetate treatment will have a bitter 
taste The excess of lead should be removed from the filtrate, before 
concentration and tasting, by treatment with hydrogen sulphide If the 
residue from the ether or chloroform extraction of the concentrated filtrate 
from a beer after treatment with lead acetate be found to be bitter, there 
is positive evidence that a foreign substitute has been employed. 

The following are characteristic reactions that may help to identify 
some of the common hop substitutes: f 

Quassiin is readily soluble by chloroform from acid solution. If a 
residue containing quassiin be moistened with a weak alcoholic solution 

* Gerichtlich-Chemische Ermittelung von Giften, St. Petersburg, 1876. 
t Allen, Analyst, 12, 1887, p. 107. 



760 FOOD INSPECTION AND ANALYSIS. 

of ferric chloride and gently heated, a marked mahogany-brown color- 
ation is produced. 

On treatment of quassiin with bromine and sodium hydroxide or 
ammonia, a bright-yellow color is shown. 

Chiretta is readily dissolved by ether from its aqueous solution. Its 
ether residue, when treated with bromine and ammonia, gives a straw 
color, slowly changing to a dull purple-brown. This is not true of 
its chloroform residue, so that it is not to be mistaken for quassia 
(Allen). 

Gentian Bitter may be extracted by treatment of the acid liquor with 
chloroform. When the residue containing gentian bitter is treated with 
concentrated sulphuric acid, in the cold, no color is produced, but on 
warming gently a carmine-red color is shown; if further treated with 
ferric chloride solution, a green-brown color is formed. 

Aloes. — This substance is separated from beer by treating the dried 
residue from 200 cc. of the beer with warm amrhonia, filtering, cooling, 
and treating the filtrate witn hydrochloric acid. The resin of aloes is 
precipitated and collected on a filter. It is insoluble in cold water, ether, 
chloroform, or petroleum ether, but is soluble in alcohol. It has a very 
characteristic odor, which serves to identify it. The hot-water solution 
gives a curdy precipitate on treatment with lead acetate. 

Capsicin is extracted by treatment of the acid liquor with chloroform. 
It is recognizable by its sharp, pungent taste. 

Detection of Arsenic. — By ihe Marsh Method. — Measure 100 cc. of 
the beer (freed from carbon dioxide by agitation) into a seven-inch porce- 
lain evaporating-dish, add 20 cc. pure concentrated nitric acid, and 3 cc. 
pure concentrated sulphuric acid, and cautiously heat till vigorous chemi- 
cal action sets in, accompanied by frothing and swelling of the beer. Turn 
the flame low or remove it altogether, and stir vigorously till the frothing 
ceases, after which the liquid may be boiled freely. At this stage 
transfer to a large casserole, and continue the boiling till nearly all 
the nitric acid is driven off. Then, holding the casserole by the handle, 
continue the heating till the mass chars and the fumes of sulphuric acid 
are given off, giving the casserole a rotary motion to prevent sputtering. 
The residue should be reduced to a dry, black, pulverulent char soon after 
the sulphuric acid fumes begin to come off freely. If still liquid, pieces of 
filter-paper should be stirred in while still heating, till the residue is dry, 
avoiding an excess of paper. 

Cool, add 50 cc. of water, and remove the masses of char from the sides 



1 



ALCOHOLIC BEVERAGES. 761 

of the dish by the stirring-rod. Heat to boiling and filter. Use the 
filtrate for the Marsh apparatus, adding it gradually. 

The arsenic mirror may be weighed in the usual manner, if of suffi- 
cient size. 

Reinsch's Test.* — Two hundred cc. of the beer are acidified with i cc. 
of pure, concentrated, arsenic-free hydrochloric acid, and evaporated to 
half its volume. 15 cc. more of hydrochloric acid are then added, and 
a piece of pure burnished copper foil half an inch long and a quarter of 
an inch wide is immersed in the liquid and kept in it for an hour while 
simmering, replacing from time to time the water lost by evaporation. If 
after the lapse of an hour the copper still remains bright, no arsenic is 
present. 

If the copper shows a deposit, remove, wash with water, alcohol, and 
ether, and dry. Then place the copper in a subliming-tube, and heat 
over a low flame. Tetrahedral crystals, apparent under the microscope, 
show the presence of arsenic. Blackening of the copper does not in itself 
prove arsenic. 

Detection and Determination of Preservatives. — See Chapter XVIII. 
Sulphurous acid may be determined by direct titration, as in the case of 
wine. 

MALT EXTRACT. 

True malt extract is a syrupy fluid having a specific gravity of from 
1.3 to 1.6, and made up in accordance with the following directions of 
the 1880 Pharmacopoeia: Upon 100 parts of coarsely powdered malt 
contained in a suitable vessel, pour 100 parts of water, and macerate 
for six hours. Then add 400 parts of water, heated to about 30° C. 
and digest for an hour at a temperature not exceeding 55° C. Strain 
the mixture with strong pressure. Finally, by means of a water-hath or 
vacuum apparatus, at a temperature not exceeding 55° C, evaporate 
the strained liquid rapidly to the consistence of thick honey. 

Keep the product in well-closed vessels in a cool place. 

Such an extract has a residue of at least 70%, consisting chiefly of 
maltose, and contains about 2% of diastase. It should furthermore l:>e 
capable of converting its own weight of starch at 55° C. in less than ten 
minutes. 

The following are analyses of three samples of pure malt extract: f 

* Jour. Soc, Chem. Ind., 20, p. 646. 

t Penn. Dept. of Agric. An. Rep., 1898, p. 85. 



762 



FOOD INSPECTION AND ANALYSIS. 





>^ 






•d.a 




c 



















< 


C8 

W 


(U 






c 

4-* 

■3 


Q 


4 
< 


1^ 


Diastatic Action. 


A 


I -,^87 





72.31 


0.231 


0.0333.32962.52 


5-25 


1. 21 


0.483 


Complete in less than s min. 


B 


1. 421 





76.65 


0.275 


o.o2i'3. 116,65.41 


6.94 


1. 190. 556 


" " " " 10 " 


C 


1.498 





79.81 0.386 

1 


0.0534.872 61.32 


12.39 


1.230.428 


" " " " 5 " 



There are on the market many so-called malt extracts widely advertised 
for their tonic and medicinal virtues, having the taste and consistency 
of beer or ale. In fact they are virtually beer, differing therefrom mainly 
in respect to price. Such "malt extracts" have no diastase, and their 
value as nutrients depends almost entirely on their sugar content. 

Harrington * has analyzed twenty-one of the best known of these 
alleged malt extracts, the maximum, minimum, and mean results of his 
analyses being as follows: 





Specific Alcohol. 
Gravity. 


Total 
Residue. 


Ash. 


Maximum 


1-0555 
I. 0149 


7-13 
0.74 

3-94 


13-63 

8.78 


0-53 
0.20 


Minimum 


Mean 









None of them contained any diastase, and several were preserved 
with salicylic acid. 

DISTILLED LIQUORS. 

These beverages differ from those hitherto considered, by reason of 
their high alcoholic content and low extract or residue. Indeed, when 
first distilled they are entirely without residue, but from long storage in 
casks, they absorb certain extractives from the wood, that impart more 
or less flavor as well as color. 

When any fermented alcoholic infusion is subjected to distillation 
under ordinary circumstances, a distillate results which consists of a 
mixture with water of a large number of alcohols, chief among which 
is ethyl alcohol. The high boiling alcohols — amyl, butyl, propyl, etc., 
with their esters — exist in the distillate in small amount, constituting 
what is known as fusel oil. The various distilled liquors of commerce 



* Boston Medical and Surgical Journal, Dec. 31, 1896. 



ALCOHOLIC BEVERAGES. 



763 



are made by just such a process of distillation, the product varying 
widely in flavor and character with the basis from which it was distilled. 

The so-called pot-still (the old-fashioned copper still and worm) 
IS well adapted for the production of potable spirits such as whiskey, 
brandy, gin, and rum, as these products should contain the congeneric 
substances which give the liquors their special character; it is not, 
however, suited for the manufacture of pure alcohol, because repeated 
distillation would be required for purification. 

Now, however, by the use of improved apparatus, such as the Coffey 
still, involving the principle of fractional condensation, it is possible to 
obtain what is known as " silent spirit," or ethyl alcohol, free from 
fusel oil. With proper appurtenances for rectifying, one can now obtain 
95% alcohol by two distillations. 

Standards for Spirits. — The following are the standards adopted 
by the Joint Committee of the Association of Official Agricultural 
Chemists and the Association of State and National Food and Dairy 
Departments: 

Distilled Spirit is the distillate obtained f'^om a fermented mash of 
cereals, molasses, sugars, fruits, or other fermentable substance, and 
contains all the volatile flavors, essential oils, and other substances 
derived directly from the material used, and the higher alcohols, ethers, 
acids, and other volatile bodies congeneric with ethyl alcohol produced 
during fermentation, which are carried over at the ordinary tempera- 
ture of distillation, and the principal part of which are higher alcohols 
estimated as amylic. 

Alcohol, Cologne Spirit, Neutral Spirit, Velvet Spirit, or Silent Spirit, 
is distilled spirit from which all, or practically all, of its constituents 
except ethyl alcohol and water, are separated, and contains not less than 
94.9% (189.8 proof) by volume of ethyl alcohol. 

Composition of Fusel Oil. — Fusel oil varies considerably in compo- 
sition with the source from which it is derived. Amyl alcchol, being 
in all cases its chief constituent, is frequently known commercially as 
fusel oil. The alcohols found in fusel oil with their formulas, specific 
gravity, and boiling-points are as follows: 



Formula. 




Boiling-point. 



Ethvl alcohol C^HjOH 

Propyl " C.H7OH 

Butyl " C.HgOH 

Amyl " ' C,Hj,OH 

Hexyl " 1 CeHigOH 



78.4° C. 
97° C. 
115° C. 

130° c. 



764 FOOD INSPECTION AND ANALYSIS. 

The following acids have been found in fusel oil, usually combined 
with the alcohols to form compound ethers: 

Acetic HC2H3O2 Caproic HCeHnOj 

Propionic HC3H5O2 CEnanthylic HC7H13O2 

Butyric HC4H7O2 Caprylic HCgHijOz 

Valerianic HC5H9O3 Pelargonic HCaHi^Oz 

Aging. — Freshly distilled liquors all contain notable quantities of 
substances, which render them harsh and unfit for use, but during 
aging, they become in several years mellow and palatable. The chemi- 
cal changes which take place during aging are discussed under whiskey. 

WHISKEY. 

Process of Manufacture. — Whiskey is the liquor resulting from the 
distillation of a fermented infusion of grain, the process being carried 
out in a pot-still, or some other form of still, constructed so that the 
resulting liquor contains not only the alcohol, but also the greater part 
of the congeneric substances which are vaporized with the alcohol. The 
fermented infusion known as the "mash" is obtained by steeping in 
water the starch-containing material, usually barley, rye, corn (maize), 
or oats mixed with malt, and subjecting the mixture to the action of 
the diastase contained in the malt, in much the same manner as the 
mashing process in the brewing of beer, except that for whiskey the 
process of saccharous fermentation is carried further, with a view to 
obtaining a maximum yield of maltose and a minimum of dextrin. 
Yeast is afterwards added, and alcoholic fermentation allowed to proceed 
with proper precautions. 

The fermented wort from whatever source obtained is subjected to 
distillation, purposely avoiding rectification or separation of the fusel 
oil and other congeneric substances which are valuable as flavors. The 
product of the first distillation is called "low wines," and is redistilled; 
the product of the second distillation is commonly divided into three 
fractions, of which the middle portion, or " clean spirit " is retained 
for the whiskey, while the first (" foreshots ") and the last fraction 
("faints") are mixed with the next portion of low wine to be redistilled. 
If the whiskey is too high in alcohol, it is diluted to the proper strength. 

As new whiskey is crude and harsh in taste, it is subjected to " aging," 
or storing in casks for a number of years. The aging process softens 
and refines the flavor, but recent investigations have proved that this 



ALCOHOLIC BEVERAGES. 765 

is not due, as formerly believed, to transformation of fusel oil into esters 
although the esters increase in amount during aging, as do also the acids 
— especially the volatile acids — the aldehydes, and the furfural. As a 
matter of fact, the percentage of fusel oil increases instead of diminishes 
on aging, due to the evaporation of water and, in a lesser degree, of 
alcohol through the wood; the actual amount, however, remains prac- 
tically the same as at the start (see table, p. 769). When first distilled, 
whiskey is perfectly colorless, but during the aging it extracts more or 
less color and some flavor from the casks in which it is stored. This 
color is especially pronounced in American whiskies, owing to the pre- 
vailing custom of charring the inside of the cask. Its flavor varies 
considerably with the nature of the grain used in its preparation. 

U. S. Rulings. — The following decision of President Roosevelt, based 
on an opinion of Attorney- General Bonaparte, was promulgated by Sec- 
retary Wilson, April 11, 1907: 

" Straight whiskey will be labeled as such. 

" A mixture or two or more straight whiskies will be labeled ' blended 
whiskey,' or ' whiskies.' 

" A mixture of straight whiskey and ethyl alcohol, provided that 
there is a sufficient amount of straight whiskey to make it genuinely a 
' mixture,' will be labeled as compound of, or compounded with, pure 
grain distillate. 

" Imitation whiskey will be labeled as such," 

This decision was overruled by President Taft, whose opinion is the 
basis of Food Inspection Decision No. 113 (Feb. 16, 1910), signed by the 
secretaries of the Treasury, Agriculture, and Commerce and Labor. The 
chief points of this decision follow: 

" All unmixed distilled spirits from grain, colored and flavored with 
harmless color and flavor, in the customary ways, either by the charred 
barrel process, or by the addition of caramel and harmless flavor, if of 
potable strength and not less than 80° proof, are entitled to the name 
whiskey without qualification. 

"Whiskies of the same or different kinds (i.e., straight, rectified, redis- 
tilled, and neutral spirits whiskies) are like substances and mixtures of such, 
with or without harmless color or flavor used for purposes of coloring and 
flavoring only, are blends. 

"Potable alcoholic distillates from sources other than grain (e.g., cane, 
fruit, or vegetables), colored and flavored, are imitations and mixtures of 
such with grain distillate are compounds. 



766 FOOD INSPECTION AND ANALYSIS. 

" A distillate [of grain (e.g., corn) flavored to simulate a whiskey of 
another kind (e.g., rye) is an imitation of that whiskey." 

Attorney- General Wickersham (F. I. D. No. 127) has further decided 
that the name " Canadian Club whiskey " is distinctive and it is therefore 
unnecessary to place the word " blend " on the label. 

Joint Standards. — The following are the standards of the Joint Com- 
mittee of the A. O. A. C. and the A. S. N. F. D. D.: 

New Whiskey is the properly distilled spirit from the properly pre- 
pared and properly fermented mash of malted grain, or of grain the starch 
of which has been hydrolyzed by malt; it has an alcoholic strength 
corresponding to the excise laws of the various countries in which it is 
produced, and contains in 100 liters of proof spirit not less than 100 grams 
of the various substances other than ethyl alcohol derived from the grain 
from which it is made, and of those produced during fermentation, 
the principal part of which consists of higher alcohols estimated as 
amylic. 

Whiskey {Potable Whiskey) is new whiskey which has been stored 
in wood not less than four years without any artificial heat save that 
which may be imparted by warming the storehouse to the usual tem- 
perature, and contains in 100 liters of proof spirit not less than 200 grams 
of the substance found in new whiskey, save as they are changed or 
eliminated by storage, and of those produced as secondary bodies during 
aging; and, in addition thereto, the substances extracted from the casks 
in which it has been stored. It contains, when prepared for consumption 
as permitted by the regulations of the Bureau of Internal Revenue, not 
less than 45% by volume of ethyl alcohol, and, if no statement is made 
concerning its alcoholic strength, it contains not less than 50% of ethyl 
alcohol by volume, as prescribed by law. 

Rye Whiskey is a whiskey in the manufacture of which rye, either 
in a malted condition or with sufficient barley or rye malt to hydrolyze 
the starch, is the only grain used. 

Bourbon Whiskey is a whiskey made in Kentucky from a mash of 
Indian corn and rye, and barley malt, of which Indian corn forms more 
than 50%. 

Corn Whiskey is whiskey made from malted Indian corn or of Indian 
corn the starch of which has been hydrolyzed by barley malt. 

Blended Whiskey is a mixture of two or more whiskeys. 

Scotch Whiskey is whiskey made in Scotland solely from barley malt, 
in the drying of which peat has been used. It contains in 100 liters of 



ALCOHOLIC BEVERAGES. 



767 



proof spirit not less than 150 grams of the various substances prescribed 
for whiskey exclusive of those extracted from the cask. 

Irish Whiskey is whiskey made in Ireland, and conforms in the pro- 
portions of its various ingredients to Scotch whiskey, save that it may 
be made of the same materials as prescribed for whiskey, and the malt 
used is not dried over peat. 

Composition. — Whiskey consists chiefly of alcohol and water, with 
relatively small amounts of fusel oil, acids, esters, aldehydes, and fur- 
fural. Its extract, derived mainly from the casks in which it is stored, 
should consist only of small amounts of tannin, sugar, and coloring 
matter. 

British Whiskies. — Scotch and Irish whiskies are aged in uncharred 
barrels, hence they are of a lighter color than the American product. 
Scotch whiskey is further characterized by its smoky taste, due to the 
peat over which it is dried. The following analyses by Vasey * illustrate 
the composition of Scotch and Irish whiskey of different ages, of neutral 
spirits used in compounding (" blending ") and adulterating, and of 
the compounded liquors: 



Grams per loo Liters of Absolute Alcohol. 



Volatile 
Acids. 



Esters. 



Alde- 
hydes. 



Furfural. 



Fusel Oil. 



Pot-still Scotch whiskey, 8 years old . 
Pot-still Scotch whiskey, 25 years old 

Irish whiskey, new 

Irish whiskey, 7 years old 

Neutral spirit for "blending" 

" Blended " Scotch 

"Scotch," probably all neutral spirits 



48.0 
64.8 
20.9 
41.8 
8.4 

39-1 
16.8 



89.7 
125. 1 

7-7 

20.9 

23.8 

106.8 



14.2 
66.1 

6.5 
11.2 



200.0 
180.0 
174.0 
204.0 
trace 
108. S 
none 



It will be noted that the congeneric substances in whiskey increase 
on aging, although in the case of fusel oil this apparent increase is 
doubtless due merely to concentration dependent on evaporation. The 
sample of neutral spirits contained only small amounts of the congeneric 
substances, while the " blended " whiskies were deficient in most of 
these substances. 

American Whiskies. — These have a deeper color than the British 
whiskies (due to the charred barrel) and a rich fruity flavor without 
the suggestion of smoke. 



* Potable Spirits, pp. 82, 83, and 87. 



768 



FOOD INSPECTION AND ANALYSIS. 



In the table below are given analyses by Shepard * of fourteen 
leading brands, including both rye and bourbon, varying in age from 
four to eight years; also of two samples of neutral spirits used for com- 
pounding and adulterating. 

A summary of the results obtained by Crampton and Tolman f in 
the analysis of fourteen brands of rye and seventeen brands of bourbon 
whiskey at differing stages of aging appear in the table on p. 769. The 
barrels were kept in U. S. bonded warehouses during aging, and samples 



Rye 

Bourbon 

Standard 

Hand-made sour mash, 

Hand-made sour mash. 
Hand-made sour mash. 



Bourbon 

Special reserve 
Sour mash ... 



Neutral spirits. 



5 

4i 

4 

4 

6 

6 

7 

5h 

7 

5 

7h 

4 









50.1 
50.1 
50.0 

49-8 

SO. 2 

49-9 

50-4 

50 

50 

49-9 

49-8 

50-1 

49-8 

50-1 

95-6 

94-4 



Grams per loo Liters of the Liquor. 



160 
162 
148 
132 
138, 

153 
180 
129 
212 
124 
177 
139 

ID 



3-2 



Acids. 



92 

68.4 

66.8 

67.1 

62.4 

49-2 

74.8 

58.8 

74-4 
60.9 

93-0 
58.2 
66.5 
50-3 



7-5 
6-3 



12.8 

9-3 

10.2 

10.2 

7-5 

7-5 

8.6 

9.9 

9.9 

7-2 

13-5 

7-2 

9.0 

6.3 
1.2 
1.4 



79-2 
59-1 
56-6 



56.9 
54-9 
41-7 
66.2 

48-9 
64-5 
53-7 
79-5 
51. c 

57-5 

44-0 

6-3 

4-9 



W 



81.8 
60.7 

55-9 
74-8 

55-9 
39-6 
61.6 
69.6 

70.8 

49-3 
94.0 
64.0 
76.6 
54-6 
15-4 
64.2 



17-5 
17-5 

lO.O 

12.0 

15-C 

8.C 

10-5 
14.0 

12.5 

9-5 

22.5 

9-5 

lo.o 

7-5 
2-5 

II. o 



3-0 

3-2 
2-4 
2.6 
2.6 
I.O 

1-3 
0.7 

2-5 

0.8 

5-0 
0-5 
1.7 
1-5 



102 
160 
130 
152 
107 
192 

137 

117. o 

141. 7 

119-5 

95-3 

193.6 

152.0 

30.0 

39-6 



were withdrawn at intervals of a year for eight years. As the minimum 
figures for certain constituents are abnormal, the next to the minimum 
figures are also given. It will be noted that during the first few years 
there was a marked increase in actual amounts of aU the constituents 
determined, except fusel oil, over and above that due to concentration, 
but after three or four years the acids and esters do not materially 
change. The rye whiskies contained larger amounts of solids, acids, 
esters, etc., than the bourbons, but this was attributed to the fact that 
heated warehouses are used for rye, and unheated for bourbon whiskey. 
The authors state that the characteristic aroma of American whiskey, 



* The Constants of Whiskey, S. Dak. Food and Dairy Commission, March, 1906. 
t Jour. Am. Chem. Soc, 30, 1908, p. 98. 



ALCOHOLIC BEVERAGES. 



769 



SUMMARY OF ANALYSES OF AMERICAN WHISKIES OF DIFFERENT AGES 





Proof. 


Grams per 100 Liters of 100 Proof Spirits. 






















Color 


Extract. 


Acids. 


Esters. 


.\lde- 
hydes. 


Fur- 
fural. 


Fusel 
Oil. 


Rye Whiskey. 


















New: Average . .. 


101.2 


0.0 


13.3 


4.4 


16.3 


5.4 


1.0 


90.4 


Maximum . 


I02.0 


0.0 


30.0 


72.0 


21.8 


15-0 


1.9 


161. 8 


Minimum * 


lOO.O 


0.0 


5-0 


12.0 


4-3 


0-7 


trace 


f 61.8 
I 43-7 


One year old: Average .-. . 


102.5 


8.8 


119.7 


46.6 


37.0 


7.0 


1.8 


111.5 


Maximum . 


104.0 


13-8 


171. 


60.5 


64.8 


15-5 


Z-3 


194.0 


Minimum * 


lOI.O 


r 7-2 

\ 6.6 


93-0 
92.0 


31-1 

5-8 


6.8\ 
6.8/ 


2.8 


0.4 


r 80.4 
I 66.4 


Two years old: Average . .. 


104.9 


11.6 


144.7 


51.9 


54.0 


10.5 


2.2 


112.4 


Maximum . 


109.0 


16.7 


199.0 


75-6 


75-1 


18.7 


5-7 


214.0 


Minimum * 


lOO.O 


r 8.8 

\ 8.6 


121. 
94.0 


44.3 
II. 


4i-5\ 
31-2/ 


5-4 


0.7 


/ 83.4 
1 82.2 


Three years old : Average . . . 


107.7 


13.2 


171.4 


62.7 


61.5 


12.5 


1.5 


112.7 


Maximum . 


112. 


18.3 


224.0 


81.8 


79.8 


20.8 


6.1 


202.0 


Minimum * 


104.0 


/ II. 4 

\ lO.I 


145-0 
119. 


52-3 
16.4 


47-61 
34-3 J 


6.5 


0.7 


/ 79-0 
\ 60.0 


Four years old: Average... 


111.2 


14.0 


185.0 


65.9 


69.3 


13.9 


2.8 


125.1 


Maximum . 


118. 


18.9 


238.0 


83-8 


89.1 


22.1 


6-7 


203.5 


Minimum * 


105.0 


rii.6 
I11-3 


156.0 
153-0 


58-6 
17-3 


57-7\ 
36-3/ 


6.4 


0.7 


r 83.8 
I 67.8 


Eight years old: Average . .. 


123.8 


18.6 


256.0 


82.9 


89.1 


16.0 


3.4 


154.2 


Maximum . 


132.0 


24.2 


339-0 


112. 


126.6 


26.5 


9-2 


280.3 


Minimum * 


112. 


/13-8 


214.0 


73-7 


68.4 1 
40.9/ 


7-9 


0.8 


r 109.0 
\107.1 






\13-7 


200.0 


31.7 




BoxTRBON Whiskey. 


















New: Average . .. 


101.0 


0.0 


26.5 


10.0 


18. 4 


3.2 


0.7 


100.9 


Maximum . 


104.0 


0.0 


161. 


29.1 


53-2 


7-9 


2.0 


171-3 


Minimum * 


100. 


0.0 


4.0 


12.0 


13.0 


I.O 


trace 


/ 71-3 
I 42.0 


One year old: Average . .. 


101.8 


7.1 


99.6 


41.1 


28.6 


5.8 


1.6 


110.1 


Maximum . 


103.0 


10.9 


193-0 


55-3 


55-9 


8.6 


7-9 


173-4 


Minimum * 


100. 


/ 5-4 
I 4-6 


61.0 

54-0 


24.7 
7.2 


17. 2I 
10.4/ 


2-7 


trace 


/ 58-0 
I 42.8 


Two years old: Average . .. 


102.2 


8.6 


126.8 


45.6 


40.0 


8.4 


1.6 


108.9 


Maximum . 


104.0 


II. 8 


214.0 


61.7 


59-8 


12.0 


9-1 


197. 1 


Minimum * 


100. 


/ 6.9 

I 5-7 


81.0 
78.0 


25-5 
23-3 


24-4 1 
II. 2 J 


5-9 


0.4 


/ 86.2 
I 42.8 


Three years old : Average . . . 


103.0 


10.0 


149.3 


54.3 


48.1 


10.5 


1.7 


112.4 


Maximum . 


106.0 


13.8 


245.0 


64.8 


73-0 


22.1 


9-5 


221.8 


Minimum.* 


100. 


/ 8.9 
I 7-0 


95-0 
90.0 


38.4 
32.1 


27-2I 
12. 1 J 


5-9 


0.6 


f 88.0 
I 43-5 


Four years old : Average . . . 


104.3 


10.8 


151.9 


58.4 


53.5 


11.0 


1.9 


123.9 


Maximum . 


108.0 


14.8 


249.0 


73-0 


80.6 


22.0 


9.6 


237-1 


Minimum * 


lOO.O 


f 8.6 

I 7-4 


lOI .0 
92.0 


40.4 
40.4 


28.2 1 
13-8/ 


6.9 


0.8 


/ 95-0 
I 43-5 


Eight years old : Average . . . 


111.1 


14.2 


210.3 


76.4 


65.6 


12.9 


2.1 


143.5 


Maximum . 


124.0 


20.9 


326.0 


91.4 


93-6 


28.8 


10. 


241.8 


Minimum * 


102.0 


/12.3 
I 10-5 


152.0 
141. 


64.1 

53-7 


37-7\ 
22.x J 


8.7 


1.0 


r iio.o 
I 47-6 



* Minimum and next to the minimum. 



770 



FOOD INSPECTION AND ANALYSIS. 



also the oily appearance and the " body " (sohds), are due to the charred 
barrels. 

Thirty-seven samples of whiskey, purchased by the glass from various 
Massachusetts saloons, were examined by the Massachusetts State 
Board of Health in 1894, with the following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 


Maximum 


45-96 
30.70 

36.51 


1.68 
0.08 
0.50 


Minimum 


Mean 





Seven of these samples had an excess of tannic acid, three had no 
tannic acid at all, and two or three had insoluble residues. 

Adulteration of Whiskey. — Imitation whiskey is often concocted by 
diluting alcohol or neutral spirit to the proper strength, coloring with 
caramel, sometimes adding for body prune juice, and adding for flavor 
certain essential oils, such as oil of wintergreen, and artificial fruit 
essences, such as oenanthic and pelargonic ethers. As a rule, a small 
amount of pure whiskey is mixed with the artificial to give it flavor. 

What has long been known as " blended whiskey " is either an 
imitation pure and simple, or a compound of whiskey and neutral spirits, 
artificially colored and flavored. According to the U. S. decisions, 
the term " blended whiskey " is restricted to a mixture of different 
kinds of grain distillate, colored and flavored. 

Among Fleischman's recipes for " blended " whiskey is the following, 
which he claims to be the very lowest grade: 

Spirits : 32 gallons 

Water 16 

Caramel -. 4 ounces 

Beading oil i ounce 



"Beading oil" is prepared by mixing 48 ounces oil of sweet almonds 
with 12 ounces C. P. sulphuric acid, neutralizing with ammonia, adding 
double the volume of proof spirits, and distilling. This preparation is 
so called because it is largely used for putting an artificial bead on cheap 
liquors. 

A little creosote is sometimes added to give a burnt taste in sem- 



ALCOHOLIC BEVERAGES. 



771 



biance of Scotch whiskey. Pungent materials such as cayenne pepper are 
said to be used as adulterants, but no record is Icnown of any substance 
being used more injurious than the alcohol. Sugar is a frec^uent adulterant. 

Some doubt exists as to the injurious effects of fusel oil on the system. 

The following analyses by Ladd * show the composition of neutral 
spirits, and imitation whiskey consisting of neutral spirits diluted with 
water, colored with caramel and flavored: 





C 
<u 
O 

< 


Grams per 100 Liters of the Liquor. 




1 




Acids. 




0) 

•0 

D 

<: 


■<5 
3 

3 








T3 
X 


1 



"3 
3 




Q4.0 

40.1 

45-8 
45-0 


2.4 
,?66.4t 

854. of 
456. of 


0.0 

4-4 
2.0 

5-5 


7-2 

43-2 

20.4 

9.6 


0.0 

9.0 

3-0 

3-0 


7.2 
34.2 
17-4 

6.6 


26.4 

3-5 
14.0 

5-2 


6.0 

trace 
trace 
trace 


trace 
0.4 

I.O 

0.8 


28.0 

37-0 
42.3 


Lnitation whiskey, rye 

" " malt . . . . 
" " rye 



t Includes caramel color. 



BRANDY AND COGNAC. 



Brandy is the product of the distillation of fermented grape juice or 
wine. In a broader sense the term brandy is sometimes applied to liquor 
distilled from the juices of other fruits, such as apples, peaches, cherries 
etc. The finest grades of brandy, such as pure cognac and armagnac 
(named from towns in France in which they were originally distilled), 
are made from choice w^hite wine by the use of pot stills, and naturally 
command a high price. Brandy of a lower grade is distilled from the 
cheaper wines, and sometimes from the fermented marc, or refuse, of the 
grape, as well as from the lees and "scrapings" of the casks. The best 
brandies are sometimes rectified by a second distillation. Like whiskey, 
the fresh brandy is colorless, and would so remain if stored in glass or 
stone. The color is due to the wooden casks in which it is stored. Brandy 
consists of nearly pure alcohol and water, having a characteristic flavor, 
differing somewhat according to the nature and quality of the wine from 
which it was prepared. The chief flavor of pure cognac is due to cenan- 
thic ether. 



■ N. Dak. Agric. Exp. Sta. Rep., 1906, Part II, p. 145. 



772 



FOOD INSPECTION AND ANALYSIS. 



Composition. — Vasey * gives the following analyses of cognac and 
of brandy adulterated with neutral spirits: 

Cognac _ 

Ten Years Old. Brandy Mixed with Neutral Spirits. 

Volatile acids 74 . 5 79 . 4 grams per 100 liters of absolute alcohol 

Esters 1093 32.4 " " " 

Aldehydes 16.6 7.4 " " " 

Furfural 1.7 0.6 " " " 

Fusel oil... 124.2 49.0 " " " 

Thirty-seven samples of brandy, collected from Massachusetts bar- 
rooms in 1894 and examined by the State Board of Health, showed the 
following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 


Maximum 


50.70 
21-30 
40-54 


3.00 
O.IO 

0-93 


Minimum 


Mean 





Three of these samples were artificially prepared mixtures of alcohol 
and water, one showed the presence of cloves, five contained tannin in 
excess, nine were excessively acid, and two had insoluble residues. 

Joint Standards. — The following are the standards of the A. O. A. C. 
and the A. S. N. F. D. D. : 

New Brandy is a properly distilled spirit made from wine, and 
contains in 100 liters of proof spirit not less than 100 grams of the 
volatile flavors, oils, and other substances, derived from the material 
from which it is made, and of the substances congeneric with ethyl alcohol 
produced during fermentation and carried over at the ordinary tem- 
peratures of distillation, the principal part of which consists of the 
higher alcohols estimated as amylic. 

Brandy {Potable Brandy) is new brandy stored in wood for not less 
than four years without any artificial heat save that which may be 
imparted by warming the storehouse to the usual temperature, and 
contains in 100 hters of proof spirit not less than 150 grams of the sub- 
stances found in new brandy, save as they are changed or eliminated 
by storage, and of those produced as secondary bodies during aging; 



'' Analysis of Potable Spirits, p. 20 



ALCOHOLIC BEVERAGES. 773 

and, in addition thereto, the substances extracted from the casks in 
which it has been stored. It contains, when prepared for consumption, 
as permitted by the regulations of the Bureau of Internal Revenue, not 
less than 45% by volume of ethyl alcohol, and, if no statement is made 
concerning its alcoholic strength, it contains not less than 50% by volume 
of ethyl alcohol as prescribed by law. 

Cognac, Cognac Brandy, is brandy produced in the departments of 
the Charente and Charente Inferieure, France, from wine produced in 
those departments. 

Adulteration of Brandy. — Much of the brandy sold on the market 
is a compound or imitation, having for its basis alcohol reduced to the 
requisite strength, flavored either by the admixture of real brandy^, or by 
various preparations such, for example, as syrup of raisins, prune juice, 
rum, acetic ether, oenanthic ether, infusion of green walnut-hulls, infusion 
of bitter almond shells, catechu, balsam of Tolu, etc. 

Fleischmann gives the following recipe for artificial brandy of the 
cheapest grade: 

Spirits 45 gallons 

Coloring (caramel) 6 ounces 

Cognac oil ^ ounce 

" Cognac oil " is made up of melted cocoanut oil 16 ounces, sulphuric 
acid 8 ounces, alcohol 16 ounces, mixed and distilled. 

While commercial brandy often fails to meet the pharmacopoeial 
requirements, and may contain any of the above flavoring materials, 
not one sample has been found among the many examined by the Massa- 
chusetts Board of Health during upwards of twenty years containing a 
more injurious ingredient than alcohol. 

Genuine new brandy may be "aged" or "improved" for immediate 
use, according to Duplais, by adding to 100 liters the following: 

Old rum 2 . 00 liters 

Oldkirsch* 1.75 " 

Infusion of walnut -hulls 75 liter 

Syrup of raisins 2 .00 liters 

The addition of sugar and caramel to brandy is very common. The 



* Brandy distilled from cherry wine. 



774 



FOOD INSPECTION AND ANALYSIS. 



lack of flavor resulting from the employment of "silent spirit," or from 
watering the product, may be compensated for by the employment of 
so-called cognac essences sold for the purpose, containing mixtures of 
the aromatic compounds named above. 

RUM. 

Rum is the liquor distilled from fermented molasses or cane juice, 
or from the scum and other waste juices from the manufacture of raw 
sugar. The molasses wort is mixed with the residue from a previous 
fermentation and allowed to ferment for a number of days, after which 
it is distilled twice and stored in wood for a long time, to remove the dis- 
agreeabfc odor, which in the new product is especially marked. The 
characteristic flavor of old rum is due to a mixture of butyric and acetic 
ether, principally the former. Pineapples and guavas are often put 
in the still to impart a fruily flavor. The best varieties of rum come 
from Jamaica and Vera Cruz. 

Composition. — The following analysis of rum is by Vascy:* 

Volatile acids. . = .,,.,...,. 28.0 grams per 100 liters of absolute alcohol 

Esters 399-0 " " " 

Aldehydes........ 8.4 

Furfural 2.8 " " 

Fusel oil-... 90.6 " " 

Thirty-nine samples of rum, sold at retail in Massachusetts in 1894, 
were examined by the State Board of Health with the following results: 





Per Cent 

Alcohol by 

Weight. 


Per Cent 
Extract. 


Maximum 


42.9 
24.7 

37-1 


3-93 
0.04 
0.51 


Minimum 


Mean ................... 





Of these, two samples were new rum, and several were entirely arti- 
ficial. 

Joint Standards. — The following are the joint standards of the 
A. O. A. C. and the A. S. N. F. D. D. : 



* Analysis of Potable Spirits, p. 85. 



ALCOHOLIC BEVERAGES. 775 

New Rum is properly distilled spirit made from the properly fer- 
mented clean, sound juice of the sugar cane, the clean, sound massacuite 
made therefrom, clean, sound molasses from the massecuite, or any sound 
clean intermediate product save sugar, and contains in loo liters of 
proof spirit not kss than loo grams of the volatile flavors, oils, ar;;! 
other substances derived from the materials of which it is made, and 
of the substances congeneric with the ethyl alcohol produced during 
fermentation, which are carried over at the ordinary temperatures of 
distillation, the principal part of which is higher alcohols estimated as 
amylic. 

Rum {Potable Rum) is new rum stored not less than four years in 
wood without any artificial heat save that which may be imparted by 
warming the storehouse to the usual temperature, and contains in loo 
liters of proof spirit not less than 175 grams of the substances found in 
new rum, save as they are changed or eliminated by storage, and of those 
produced as secondary bodies, during aging; and, in addition thereto, 
the substances extracted from the casks. It contains, wlien prepared 
for consumption as permitted by the regulations of the Bureau of Inter- 
nal Revenue, not less than 45% by volume of ethyl alcohol, and if nc 
statement is made concerning its alcoholic strength, it contains not les& 
than 50% by volume of ethyl alcohol as prescribed by law. 

More or less factitious rum is sold on the market, made up of alcohol 
diluted to the right strength, colored with caramel, and flavored by the 
addition of '* rum essence." Prune juice is sometimes added. 

Fleischman gives the following recipe for low-grade artificial rum; 

Spirits '. 40 gallons 

New England rum 5 " 

Prune juice ^ gallon 

Caramel 12 ounces 

Rum essence 8 " 

The "rum essence" is made up by distilling 32 ounces of a mixture 
of 2 ounces black oxide of manganese, 4 ounces pyroligneous acid, 32 
ounces alcohol, and 4 ounces sulphuric acid. To this is added 32 ounces 
of acetic ether, 8 ounces of butyric ether, 16 ounces safiFron extract, and 
i ounce oil of birch. 



776 FOOD INSPECTION AND ANALYSIS. 



Gin. 



Gin is an alcoholic liquor, flavored with the volatile oil of juniper and 
sometimes with other aromatic substances, such as coriander, grains of 
paradise, anise, cardamom, orange-peel, and fennel. The choicest variety 
is known as Schiedam schnapps, named from the town of Schiedam in 
Holland, where there are upwards of 200 distilleries devoted to the manu- 
facture of gin. The mash used for this variety is fermented by yeast 
from malted barley and rye, after which it is distilled and redistilled 
in pot stills with juniper berries and sometimes hops. 

Juniper berries, to which the most characteristic flavor of gin is due, 
are dark blue in color, and possess a pungent taste. They grow on the 
slender evergreen shrub Juniperus communis. Gin differs from the 
other distilled liquors by being water-white. To this end it is kept in 
glass and not in wood. 

Much of the gin of commerce is made by redistilling com or grain 
whiskey with oil of juniper, and frequently one or several of the above- 
named flavoring materials. Sugar is often added, and sometimes in the 
cheaper productions oil of turpentine is substituted for juniper oil. 

Composition. — The following analysis of unsweetened gin is by Vasey : * 

Volatile acids 0.0 grams per 100 liters of absolute alcohol 

Esters 37-3 

Aldehydes 1-8 " " 

Furfural.. o.o *' • " . " 

Fuseloil 44.6 ** *f " 

■ Thirty-three samples of gin, purchased in Massachusetts saloons and 
analyzed by the State Board of Health in 1894, gave the following 
results in per cent of alcohol by weight: Maximum 42.5, minimum 29.5, 
mean 38.2. 

* Analysis of Potable Spirits, p. 85. 



ALCOHOLIC BEVERAGES. 777 



METHODS OF ANALYSIS OF DISTILLED LIQUORS. 

Specific gravity and alcohol are determined as described on pp. 686- 
706. The following methods with the exception of the qualitative test 
for fusel oil, Mitchell's method, and McGill's opalescence test are 
those of the A. O. A. C. 

Determination of Extract.— Weigh or measure (at 15.6° C.) 100 cc. 
of the sample, evaporate nearly to dryness on the water-bath, then 
transfer to a water-oven, and dry at the temperature of boiling water 

for 2^ hours. 

Determination of Acids.— Titrate 100 cc. (or 50 cc. diluted to 100 cc. 
if the sample is dark in color) with tenth-normal alkali, using phenol- 
phthalein as indicator, i cc. of tenth-normal alkali is equal to 0.006 of 

acetic acid. 

Determination of Esters.— Dilute 200 cc. of the sample with 25 cc. 
of water and distil slowly into a graduated 200-cc. flask until nearly 
fiUed to the mark. Complete the volume, shake, and use aliquot 
portions for the determination of esters, aldehydes, and furfural. 

Exactly neutralize 50 cc. of the distillate with tenth-normal alkah, 
using phenolphthalein as indicator, and add from 25 to 50 cc. of the 
tenth-normal alkali in excess of that required for neutralization. Either 
boil for one hour with a reflux condenser, or allow to stand overnight 
in a stoppered flask, and heat with a tube condenser for one-half hour 
below the boiling-point. Cool, and titrate with tenth-normal acid, using 
phenolphthalein as indicator. Mukiply the number of cc. of tenth- 
normal alkali used in the saponification by 0.0088, thus obtaining the 
grams of esters calculated as ethyl acetate. 

Determination of Aldehydes.-i. Reagents.-{a) Alcohol Free from 
Aldehydes.-Frepa.re by first redistilling the ordinary 95% alcohol over 
caustic soda or potash, then add from 2 to 3 grams per liter of m-phenyl- 
enediamine hydrochloride, digest at ordinary temperature for several 
days (or reflux on the steam-bath for several hours), and then distfl 
slowly, rejecting the first 100 cc. and the last 200 cc. 

(&) Sulphite-fuchsin Solution.— Dissolve 0.50 gram of pure fuchsin 
in 500 cc. of water, then add 5 grams of SO2 'dissolved in water, make 
up to a hter, and allow to stand until colorless. Prepare this solution 
in smaU quantities, as it retains its strength for only a very few days. 



778 FOOD INSPECTION AND ANALYSIS 

(c) Standard Acetic Aldehyde Solution. — Prepare according to the 
directions of Vasey * as follows: Grind aldehyde ammonia in a mortar 
with ether, and decant the ether. Repeat this operation several times, 
then dry the purified salt in a current of air and finally in a vacuum 
over sulphuric acid. Dissolve 1.386 grams of this purified ammonium 
aldehyde in 50 cc. of 95% alcohol, to this add 22.7 cc. of normal alco- 
holic sulphuric acid, then make up to 100 cc. and add 0.8 cc. to com- 
pensate for the volume of the ammonium sulphate precipitate. Allow 
this to stand over night and filter. This solution contains i gram of 
acetic aldehyde in 100 cc. and will retain its strength. 

The standard found most convenient for use is 2 cc. of this strong 
aldehyde solution diluted to 100 cc. with 50% alcohol by volume. One 
cc. of this solution is equal to 0.0002 gram of acetic aldehyde. This solu- 
tion should be made up fresh every day or so, as it loses its strength. 

2. Process. — Determine the aldehyde in the distillate prepared for 
esters. Dilute from 5 to 10 cc. of the distillate to 50 cc. with aldehyde- 
free alcohol (50% by volume), add 25 cc. of the fuchsin solution, and 
allow to stand for fifteen minutes at 15° C. The solutions and the 
reagents should be at 15° C. before they are mixed. Prepare standards 
of known strength in the same way. 

Determination of Furfural. — Standard Furfural Solution. — Dissolve 
I gram of redistilled furfural in 100 cc. of 95% alcohol. This strong 
solution will keep. Standards are made by diluting i cc. of this solution 
to 100 cc. with 50% by volume alcohol. One cc. of this solution con- 
tains 0.000 1 gram furfural. 

Process. — Dilute from 10 to 20 cc. of the distillate, prepared as 
described under esters, to 50 cc. with furfural-free alcohol (50% by 
volume). To this add 2 cc. of colorless anilin and 0.5 cc. of hydro- 
chloric acid (specific gravity 1.125), and keep for fifteen minutes in a 
water-bath at about 15° C. Prepare standards of known strength in 
the same way. 

Detection of Fusel Oil. — In the process of dealcoholizing a liquor by 
evaporation in an open dish over the water-bath, one may readily detect 
fusel oil, if present, by its harsh and nauseating odor, if the nose is 
applied just at the moment when the last traces of alcohol are going 
off. At this stage any considerable trace of fusel oil will be especially 
apparent by the effect on the throat of the one who smells it, causing 

* Analysis of Potable Spirits, p. 30. 



ALCOHOLIC BEVERAGES. 779 

an uncontrollable desire to cough. Other ways of applying the odor 
test consist in pouring a small portion of the spirit into the hand, and 
allowing it to evaporate slowly therefrom, or in rinsing out a warm glass 
with the liquor, observing the odor in each case. 

Goebel suggests the following test, based on the detection of the 
volatile acids: Agitate about 30 cc. of the liquor with 2 or 3 cc. of 
a dilute solution of potassium hydroxide; evaporate over the water- 
bath to the volume of 2 or 3 cc, cool, and to the residue add 5 or 6 cc. 
of concentrated sulphuric acid. If fusel oil be present, the character- 
istic odors of valerianic and butyric acids will be apparent. 

Determination of Fusel Oil. — Allen-Mar quardt Method. — Add to 
100 cc. of whiskey 20 cc. of half-normal sodium hydroxide, and saponify 
the mixture by boiling for one hour under a reflux condenser.* Connect 
the flasks with a distilhng apparatus, distil 90 cc, add 25 cc. of water, 
and continue the distillation until an additional 25 cc is collected. 

Approximately saturate the distillate with finely ground sodium 
chloride, and add a saturated solution of sodium chloride until the specific 
gravity is i.io. 

Extract this salt solution four times with carbon tetrachloride,! using 
40, 30, 20, and ID cc. respectively, and wash the carbon tetrachloride 
three times with 50-cc portions of a saturated solution of sodium chloride, 
and twice with saturated solution of sodium sulphate. Then transfer 
the carbon tetrachloride to a flask containing 5 cc. of concentrated 
sulphuric acid, 45 cc of water, and 5 grams of potassium bichromate, 
and boil for eight hours under a reflux condenser. 

Add 30 cc. of water, and distil until only about 20 cc. remain; add 
80 cc of water, and distil until but 5 cc are left. Neutralize the distillate 
to methyl orange, and titrate with sodium hydroxide, using phenol- 
phthalein as indicator. One cc. of tenth-normal sodium hydroxide is 
equivalent to 0.0088 gram of amyl alcohol. 

Rubber stoppers can be used in the saponification and first distilla- 
tion, but corks covered with tinfoil must be used in the oxidation and 
second distiUation. Corks and tinfoil must be renewed frequently. 



* Or 100 cc. of the liquor may be mixed with 20 cc. of half-normal sodium hydroxide, 
allowed to stand overnight at room temperature, and distilled directly. 

t Purify 5 liters of carbon tetrachloride by boiling for several hours under a reflux con- 
denser with 200 cc. of sulphuric acid and 25 grams of potassium bichromate in 200 cc. of 
water; separate from the oxidizing mixture by distillation, and redistil over barium car- 
bonate. 



780 FOOD INSPECTION AND ANALYSIS. 

Tolman and Hillyer^s Modification of the Allen- Marquardt Method. — 
Proceed with the Allen-Marquardt method to the point where the 
carbon tetrachloride solution of the higher alcohols is ready to be 
oxidized. Add 50 cc. of a solution of 200 grams of pulverized potassium 
bichromate in 1800 cc. of water and 200 cc. of concentrated sulphuric 
acid, very carefully measured with pipette or burette, and start the 
eight-hour oxidation. Take great care to prevent any isolation of spots 
of bichromate on the flask during the oxidation. Decomposition of 
the bichromate from overheating can best be prevented by slow boiling 
over several thicknesses of asbestos board. After the oxidation is 
complete, separate the bichromate solution from the carbon tetrachloride 
in a separatory funnel, care being taken to wash the carbon tetrachloride 
free from bichromate. Make up the bichromate solution to 500 cc. 
Place 200 cc. of this solution in a liter flask, add 20 cc. of concentrated 
hydrochloric acid, 100 cc. of potassium iodide solution (1:1), and 50 cc. 
of approximately three-fourths normal thiosulphate not standardized. 
Make this last addition by means of a burette. (If a high content of 
fusel oil is present, 50 cc. of thiosulphate may be excessive and a smaller 
amount should be used, the same quantity being added to the sample 
and to the blank.) Run blanks containing exactly the same amount 
of reagents with each series, and treat them in the same way, starting 
them at the point where the carbon tetrachloride is washed with sodium 
chloride. The titration of this blank, to which has been added exactly 
the same amount of three-fourths normal thiosulphate, gives the value 
of the bichromate solution. The difference in cubic centimeters of tenth- 
normal thiosulphate used in titrating the blank and the samples gives 
the amount of bichromate reduced by the higher alcohols. This differ- 
ence in cubic centimeters of tenth-normal thiosulphate multiplied by 
the factor 0.001773 gives grams of higher alcohols present. 

Mitchell and Smith Method."^ — This is more rapid than the Allcn- 
Marquardt method and gives more nearly the true amount of fusel oil. 

Saponify, distil, shake with sodium chloride, and extract with carbon 
tetrachloride, as in the Allen-Marquardt method. To the carbon tetra- 
chloride extract, contained in the separatory funnel, add 10 cc. of 
potassium hydroxide solution (1:1). Cool the mixture in ice-water to 
approximately 0° C. Similarly cool 100 cc. of a solution of potassium 
permanganate solution (20 grams to the liter), accurately measured in 

* A. O. A. C. Proc. 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 199. 



ALCOHOLIC BEVERAGES. 781 

a flask. To the contents of the separatory funnel add the bulk of the 
permanganate solution, but without rinsing, retaining the residue to be 
added at a later stage. Remove the mixture from the bath, and shake 
vigorously for five minutes; set aside for thirty minutes, with occasional 
shaking, permitting the hquid to warm to room temperature (20 to 25° C.) 

Accurately measure into a liter Erlenmeyer flask 100 cc. of a solution 
of hydrogen peroxide slightly (about 2%) stronger than the perman- 
ganate solution, acidulate with 100 cc. of an approximately 25% sul- 
phuric acid solution, and slowly add the contents of the separatory 
funnel with constant shaking, keeping the acid solution constantly in 
excess. Rinse the separatory funnel and the flask containing the residue 
of permanganate with water and add to the peroxide solution. Finally 
titrate the excess of hydrogen peroxide with standard potassium per- 
manganate solution (10 grams to the flter). 

Run a blank determination, using the same amounts of the stronger 
permanganate, potassium hydroxide, hydrogen peroxide, and sulphuric 
acid solutions, and titrating the residual peroxide with the standard 
potassium permanganate as before. 

The difference in the amounts of permanganate consumed, in grams, 
times 0.696, gives the amount of amyl alcohol. 

Detection of Methyl Alcohol. — Leach and Lythgoe Immersion Refrac- 
tometer Method.^ — Determine at 20° C. the refraction of the distiflate 
obtained in the determination of alcohol by the immersion refractometer. 
If on reference to the table the refraction shows the percentage of alcohol 
agreeing with that obtained from the specific gravity, it may be safely 
assumed that no methyl alcohol is present. If, however, there is an 
appreciable amount of methyl alcohol, the low refractometer reading will 
at once indicate the fact. If the absence from the solution of other 
refractive substances than water and the alcohols is assured, this quali- 
tative test by difference in refraction is conclusive. 

The addition of methyl to ethyl alcohol decreases the refraction in 
direct proportion to the amount present; hence the quantitative calcu- 
lation is readily made by interpolation in the table, using the figures 
for pure ethyl and methyl alcohol of the same alcoholic strength as the 
sample. 

Example. — Suppose the distillate made up to the original volum.e 
of the measured portion taken for the alcohol determination has a 

* Tour. Am. Chem. Soc, 27, 1905, p. 964. 



782 



FOOD INSPECTION AND ANALYSIS. 



specific gravity of 0.9736, corresponding to 18.38% alcohol by weight, 
and has a refraction of 35.8 at 20° C. by the immersion refractometer; 
by interpolation in the refractometer table the readings of ethyl and 
methyl alcohol corresponding to 18.38% alcohol are 47.2 and 25.4, 
respectively, the difference being 21.8; 47.2 — 35.8=11.4; (11.4-^21.8) 
100=52.3, showing that 52.3 of the alcohol present is methyl alcohol. 



SCALE READINGS ON ZEISS IMMERSION REFRACTOMETER AT 20° C, 
CORRESPONDING TO EACH PER CENT BY WEIGHT OF METHYL AND 
ETHYL ALCOHOLS. 





Scale 




Scale 




Scale 




Scale 




Read 


ngs. 




Read 


ngs. 




Readings. 




Readings. 


Per Cent 






Per Cent 
Alcohol 






Per Cent 
Alcohol 




Per Cent 
Alcohol 






Alcohol 


















by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 


by 
Weight. 


Methyl 
Al- 


Ethyl 
Al- 




cohol. 


cohol. 




cohol. 


cohol. 




cohol. 


cohol. 




cohol 


cohol. 





14-S 


14.5 


26 


3°-3 


61.9 


51 


39-7 


91. 1 


76 


29.0 


lOI.O 


I 


14.8 


16.0 


27 


30-9 


63-7 


52 


39-6 


91.8 


77 


28.3 


100.9 


2 


15-4 


17.6 


28 


31.6 


65-5 


53 


39-6 


92.4 


78 


27.6 


100.9 


3 


16.0 


19. 1 


29 


32.2 


67.2 


54 


39-5 


93-0 


79 


26.8 


100.8 


4 


16.6 


20.7 


30 


32-8 


69.0 


55 


39-4 


93-6 


80 


26.0 


100.7 


S 


17.2 


22.3 


31 


33-5 


70.4 


56 


39-2 


94-1 


81 


25-1 


100.6 


6 


17.8 


24.1 


32 


34-1 


71.7 


57 


39-0 


94.7 


82 


24-3 


100. 5 


7 


18.4 


25-9 


33 


34-7 


73-1 


58 


38.6 


95-2 


83 


23-6 


100.4 


8 


19.0 


27.8 


34 


35-2 


74-4 


59 


38-3 


95.7 


84 


22.8 


100.3 


9 


19.6 


29.6 


35 


35-8 


75.8 


60 


37-9 


96.2 


85 


21.8 


100. 1 


10 


20.2 


31-4 


36 


3^-3 


76.9 


61 


37-5 


96.7 


86 


20.8 


99.8 


II 


20.8 


33-2 


37 


36.8 


78.0 


62 


37-0 


97-1 


87 


19.7 


99-5 


12 


21.4 


35-0 


38 


37-3 


79-1 


63 


36.5 


97-5 


88 


18.6 


99-2 


13 


22.0 


36.9 


39 


37-7 


80.2 


64 


36.0 


98.0 


89 


17-3 


98.9 


14 


22.6 


38-7 


40 


38-1 


81-3 


65 


35-5 


98.3 


90 


16. I 


98.6 


IS 


23.2 


40.5 


41 


38.4 


82.3 


66 


35-0 


98.7 


91 


14.9 


98.3 


16 


23-9 


42.5 


42 


38.8 


83-3 


67 


34-5 


99.1 


92 


13-7 


97.8 


17 


24-5 


44-5 


43 


39-2 


84.2 


68 


34-0 


99-4 


93 


12.4 


97-2 


18 


25.2 


46.5 


44 


39-3 


85-2 


69 


33-5 


99-7 


94 


II. 


96-4 


19 


25.8 


48.5 


45 


39-4 


86.2 


70 


33-0 


100. 


95 


9-6 


95-7 


20 


26.5 


50.5 


46 


39-5 


87.0 


71 


32-3 


100.2 


96 


8.2 


94.9 


21 


27.1 


52.4 


47 


39-6 


87.8 


72 


31-7 


100.4 


97 


6-7 


94.0 


22 


27.8 


54-3 


48 


39-7 


88.7 


73 


31-1 


100.6 


98 


S-i 


93.0 


23 


28.4 


56.3 


49 


39-8 


89-5 


74 


30-4 


100.8 


99 


3-5 


92.0 


24 


29.1 


58.2 


50 


39-8 


90-3 


75 


29.7 


lOI.O 


100 


2.0 


91.0 


25 


29-7 


60.1 





















Trillat Method.^ — To 50 cc. add 50 cc. of water and 8 grams of hme, 
and fractionally distil by the aid of Glinksy bulb tubes. Dilute the 



* A. Trillat, Analyst, 24, 1899, pp. 13, 211-212. 



ALCOHOLIC BEVERAGES. 783 

first 15 cc. of the distillate to 150 cc, mix with 15 grams of potassium 
bichromate and 70 cc, of sulphuric acid (1:5), and allow to stand for 
one hour with occasional shaking. 

Distil, reject the first 25 cc, and collect 100 cc. Mix 50 cc. of the 
distillate with i cc of rectified dimethyl-anilin, transfer to a stout, 
tightly-stoppered flask, and keep on bath at 70 to 80° C. for three hours 
with occasional shaking. Make distinctly alkaline with sodium hydrox- 
ide, and distil the excess of dimethyl-anilin, stopping the distillation 
when 25 cc. have passed over. 

Acidify the residue in the flask with acetic acid, shake, and test a 
few cc. by adding four or five drops of water with lead dioxide in 
suspension (i gram in 100 cc). If methyl alcohol be present, a blue 
coloration occurs which is increased by boiling. 

Note. — Ethyl alcohol thus treated yields a blue coloration, changing 
immediately to green, afterwards to yellow, and becoming colorless when 
boiled. 

Riche and Bardy Methoa.* — The following method for the detection 
of methyl alcohol in commercial spirit of wine depends on the formation 
of methyl-anilin violet: 

Place 10 cc. of the sample, previously rectified over potassium car- 
bonate if necessary, in a small flask with 15 grams of iodine and 2 grams 
of red phosphorus. Keep in ice-water for from ten to fifteen minutes 
until action has ceased. Distil on a water-bath the methyl and ethyl iodides 
formed into about 30 cc. of water. Wash with dilute alkali to eliminate 
free iodine. Separate the heavy oily liquid which settles, and transfer 
to a flask containing 5 cc. of anilin. The flask should be placed in cold 
water, in case the action should be violent, or, if necessary, the reaction 
may be stimulated by gently warming the flask. After one hour boil 
the product with water, and add about 20 cc of a 15% solution of soda; 
when the bases rise to the top as an oily layer, fill the flask up to the 
neck with water, and draw them off with a pipette. Oxidize i cc of 
the oily liquid by adding 10 grams of a mixture of 100 parts of clean 
sand, 2 of common salt, and 3 of cupric nitrate; mix thoroughly, intro- 
duce into a glass tube, and heat to 90° C. for eight or ten hours. Exhaust 
the product with warm alcohol, filter, and make up with alcohol to 100 cc. 
If the sample of spirits be pure, the liquid is of a red tint, but in the 
presence of 1% of methyl alcohol, it has a distinct violet shade; with 

* Allen's Commercial Organic Analysis, 3d ed., I, p. 80, 



784 



FOOD INSPECTION AND ANALYSIS. 




2.5% the shade is very distinct, and still more so with 5%. To detect 
more minute quantities of methyl alcohol, dilute 5 cc. of the colored 
hquid to 100 cc. with water, and dilute 5 cc. of this again to 400 cc. Heat 
the liquid thus obtained in porcelain, and immerse a fragment of white 
merino (free from sulphur) in it for half an hour. If the alcohol be 
pure, the wool will remain white, but if methylated, the fiber will become 
violet, the depth of tint giving a fair approximate in- 
dication of the proportion of methyl alcohol present. 

Detection of Caramel. — Crampton and Simon's 
Method.'^ — Evaporate 50 cc. of the liquor nearly but not 
quite to dryness in an evaporating-dish on the water-bath. 
Wash with water into a 50-cc. graduated glass-stoppered 
flask, add 25 cc. of absolute alcohol, and fill to the mark 
with water. Shake, and transfer 25 cc. of the solution 
to a separatory funnel of the type presented in Fig. 116, 
the stem of which terminates in a 25-cc. graduated 
bulb pipette, provided with a stop-cock as shown. 

Add 50 cc. of ether, and shake carefully at intervals 
during half an hour. After complete separation, make 
up the lower aqueous layer with water to the 25-cc. 
mark, which may be done by siphoning it in through 
a rubber tube from an elevated flask, controlling the 
supply by the stop-cock. Shake the separatory funnel, 
and again allow the layers to separate, draw off the 
Fig. 116. — Separa- aqueous layer, and compare with the color of the orig- 

Express the amount of color removed as 
per cent of the total amount. Ether will readily dis- 
solve the natural color due to oakwood (mainly flave- 
scin), while caramel is insoluble in ether; hence uncolored liquors are 
partially decolorized by this treatment, while those colored with caramel 
show little change. 

Amihor Test, Modified by Lasche.'\ — Add 10 cc. of paraldehyde to 
5 cc. of the sample contained in a test tube and shake. Add absolute 
alcohol, a few drops at a time, shaking after each addition until the 
mixture becomes clear. Allow to stand. Turbidity after ten minutes 
is an indication of caramel. 



tory Funnel for j^^j jj 
Detecton of 



Caramel. 



* Jour. Am. Chem. Soc, 22 1900, p. 810. 
f The Brewer Distiller, May, 1903. 



ALCOHOLIC BEVERAGES. 785 

Determination of Water-insoluble Color in Whiskies. — Evaporate 
50 cc. of the sample just to dryness. Take up with cold water, using 
approximately 15 cc., filter, and wash until the filtrate amounts to nearly 
25 cc. To this filtrate add 25 cc. of absolute alcohol or 26.3 cc. of 95% 
by volume alcohol, and make up to 50 cc. by the addition of water. 
Mix thoroughly and compare in a colorimeter with the original material. 
Calculate the per cent of color insoluble in water from these readings. 

Determination of Color Insoluble in Amyl Alcohol. — Modified Marsh 
Test. — Evaporate 50 cc. of the whiskey just to dryness on the steam- 
bath. Add 26.3 cc. of 95% alcohol to dissolve the residue. Transfer 
to a 50-cc. flask and make up to volume with water to obtain a uniform 
alcohol concentration. Place 25 cc. of this solution in a separatory 
funnel, and add 20 cc. of the Marsh reagent, shaking lightly so as not 
to form an emulsion. (This reagent consists of 100 cc. of pure amyl 
alcohol, 3 cc. of syrupy phosphoric acid, and 3 cc. of water; shake 
before using.) Allow the layers to separate, and repeat this shaking 
and standing twice again. After the layers have clearly separated, draw 
off the lower or watery layer which contains the caramel into a 25-cc. 
cylinder, and make up to volume with 50% by volume alcohol. Com- 
pare this solution in a colorimeter with the untreated 25 cc. Calculate 
the result of this reading to the per cent of color insoluble in amyl 
alcohol. 

Opalescence in Diluted Alcohol Distillate. — McGill * has shown that 
in the case of liquors made from thoroughly rectified grain spirit, there 
is little or no opalescence produced when the alcohohc distillate (i.e., 
that used in determining the alcohol) is diluted with an equal volume 
of water, while in the case of liquors distilled from alcoholic infusions 
without rectification, the opalescence is marked. He ascribes the opales- 
cence to the presence of minute amounts of volatile oils present in wine 
maic, grains, and other sources of these liquors, soluble in strong, but 
insoluble in dilute alcohol. Whether due to this or to the separation 
of minute traces of fusel oil on dilution, the presence or absence of tur- 
bidity certainly furnishes a rough distinguishing test, indicating in some 
cases the exclusive use of rectified spirit. 

* Bui. 27, Canadian Inland Rev. Dept. 



786 FOOD INSPECTION AND ANALYSIS. 

LIQUEURS AND CORDL/aS. 

These are manufactured beverages, usually high in alcohol and sugar, 
flavored with a wide variety of aromatic herbs or essences, and often 
strongly colored. Red colors most frequently used for this purpose 
are cochineal, cudbear, and red sandal and Brazil woods; for yellow 
colors, caramel and saffron-yellow are employed; for blue, indigo; and 
for green, chlorophyll and malachite green. 

Some of the oldest of the liqueurs, such as chartreuse and bencdictine, 
derive their names from certain monasteries of Europe, in which they 
have been made for many years. 

Absinthe is one of the best-known cordials, made by redistilling 40% 
alcohol in which wormwood, anise, sweet flag, and marjoram leaves 
have been macerated. Sometimes coriander and fennel are also used. 
It is highly intoxicating. 

Curasao is made by Histilling dilute spirits in which Curasao orange- 
peel,* cinnamon and often other spices have been soaked, and by adding 
sugar to the resulting liqueur. 

De Brevans gives the following recipe for curafoa: 

Rasped skins of. . 18 or 20 oranges 

Cinnamon 4 grams 

Mace 2 " 

Alcohol (85%) 5 liters 

White sugar 1 750 grams 

Macerate for fourteen days, distill without rectification, and color with 
caramel. 

Angostura owes its flavor to Angostura bark and various spices. 

Maraschino had originally for its basis the fermented juice of the 
sour Italian cherry, to which honey was added. It is more commonly 
made by distilling a mixture in alcohol of ripe wild cherries, raspbenies. 
cherry leaves, peach nuts, and orris. Finally sugar is added. 

Chartreuse and Benedictine contain much sugar, and are flavored 
with the volatile oils of angelica, hyssop, nutmeg, and peppermint. 

Noyau, or Crime de Noyau, is a preparation distilled from* brandy, 
bitter almonds, mace and nutmeg. Sugar and coloring matter, usually 
pink, are added to the final product. 

Crime de Menthe, according to De Brevans, is made by distilling a 
mixture of 

* This is a very rare and highly-prized orange, growing in the island of Curacao. 



ALCOHOLIC BEVERAGES. 



787 



Peppermint 600 grams 

Balm 40 " 

Sage 10 " 

Cinnamon 20 " 

Orris root 10 " 

Ginger 15 " 

Alcohol (80%) 5030 cc. 

producing finally 10 liters of the liquor, after 3750 grams of white sugar 
have been introduced. 

The better grades of creme de mcnthe were formerly colored with 
an alcoholic solution of chlorophyll, derived by macerating bruised green 
leaves of various plants with alcohol, but at present, coal-tar dyes are 
used. Frequently the desired shade is secured by mixing a green (e.g., 
Light Green S.F.), a blue-green (e.g.. Malachite Green), or a blue (e.g., 
Indigo Carmine) with a yellow color. 

The following analyses, due to Konig, show the chemical composition 
of the best-known cordials: 



Specific 
Gravity. 



Alcohol 
by Vol- 
ume. 



Alcohol 

by 
Weight. 



Extract. 



Cane 
Sugar. 



Other 
Extrac- 



Ash. 



Absinthe 

Benedictine 

Ginger 

Creme de menthe 

Anisette de Bordeaux. . 

Curai;oa 

Kiimmel 

Angostura 

Chartreuse 



0.9116 
1.0709 
I. 0481 
1.0447 
1.0847 
I . 0300 
1.0830 
0.9540 
1.0799 



58.93 
52 

47-5 
48.0 
42.0 
55-0 
33-9 
49-7 
43.18 



38-5 
36.0 

36-5 
30-7 

42-5 
24.8 



0.18 
36.00 
27.79 
28.28 
34.82 
28.60 
32.02 

5-85 
36.11 



32-57 
25.92 
27.63 

37-44 
28.50 
31.18 
4. 16 
34-35 



0.32 

3-43 
1.87 
0.65 
0.38 
o.io 
0.84 
1 .69 
1.76 



0.043 
0.141 
0.068 
0.040 
0.040 
0.058 



Analysis of Cordials and Liqueurs. — The character of the essences 
and flavoring principles used in these beverages is so widely varied that 
no regular systematic plan for identifying them can be made applicable 
to all cases. The senses of smell and taste are most useful, both when 
applied directly to the liqueur itself and to the dry extract, for suggestions 
as to the main ingredients employed. Coloring-matters, sugars, acids, 
and alcohol are determined as with other liquors, except that in the case 
of alcohol all volatile oils must first be separated out by treatment with 
magnesia, as directed for alcohol in lemon extract. Presence of volatile 
oils is shown, if on treatment of a few cubic centimeters of the sample in 
a test-tube with water a precipitate is formed. 



CHAPTER XVI 
VINEGAR. 

True vinegar is the product of the acetic fermentation of an alcoholic 
liquid under the influence of the organism Mycoderma aceti, existing 
in the " mother-of- vinegar." While vinegar may be made directly from 
a dilute solution of pure alcohol, it is commonly obtained from fruit juice, 
wine, or other saccharine liquid that has first undergone alcoholic fer- 
mentation. 

Of the following equations (i) and (2) illustrate the processes of 
inversion and alcoholic fermentation respectively, while (3) and (4) show 
the double process of acetic fermentation, wherein the alcohol is oxidized, 
first to acetaldehyde and finally to acetic acid : 

Ci2Ho20n+H20--2C6Hi206; (i) 

Cane sugar Invert sugar 

C6Hi206 = 2C2H60+2C02; (2) 

Invert sugar Alcohol _ - i 

C2H60+0 = C2H40+H20; (3) 

Alcohol Aldehyde _ , 

C2H40+0 = C2H402 (4) 

Aldehyde Acetic acid 

Varieties. — The principal varieties of vinegar are the following: Cider 
vinegar, wine vinegar, malt or beer vinegar, spirit or distilled vinegar, glucose 
vinegar, sugar or molasses vinegar, and wood vinegar or diluted pyroligneous 
acid, the four last being frequently used as adulterants of the others. 

Cider and distilled vinegar are the principal varieties used in the United 
States and Canada, malt vinegar is the common variety in Great Britain 
and wine vinegar on the continent. 

In addition to the acetic acid, its chief active principle, vinegar contains 
small amounts of other substances present in the raw material or formed 
during the alcoholic and acetic fermentations. To the former class belong 
the acids of the apple and grape and to the latter, succinic and lactic acids. 

788 



VINEGAR. 789 

Alcohol, in greater or less amount depending on the completeness of aceti- 
fication, is present in all true vinegar. Reducing sugar and other carbo- 
hydrates in minute amount, glycerol, coloring matters, aromatic ethers, 
and mineral salts occur in all kinds but distilled and wood vinegar. Other 
minor constituents of cider vinegar are pentosans,* furfural,! and acetyl- 
methylcarbinol.l Distilled vinegar contains only traces of solids. Wood 
vinegar contains considerable amounts of formic acid; cider vinegar and 
malt vinegar none or only traces. § 

Manufacture of Vinegar. — Cider and wine vinegar were formerly 
made almost entirely by the slow process of cask fermentation, the fruit 
juice being allowed to undergo both alcoholic and acetic fermentation in 
barrels with open bung-holes in a warm cellar, or exposed to the sun. 
Two or three years are required for this process. Sometimes fresh cider 
or wine is added to the barrels at regular intervals of two or three weeks, 
thus causing a series of progressive fermentations. The acetic fermenta- 
tion is hastened by adding old vinegar, or mother-of-vinegar. While 
farmers and some manufacturers still continue to use the slow process 
quick or " generator " vinegar processes are now much used not only for 
malt, beer, and spirit vinegar but also for cider and wine vinegar. 

There are two types of generators: (i) Tank Generators, provided 
with false bottoms, containing beech shavings, birch twigs, corn cobs, 
or other woody material, previously saturated with old vinegar, through 
which the alcoholic liquor percolates and is brought in contact with a 
current of air passed up from below, and (2) Rotating Generators consisting 
of rectangular tanks containing the alcoholic liquor into which dip slowly 
revolving drums containing beech shavings. In the former process the 
acetification is completed in two or three days, in the latter, in about four 
weeks. 

The alcoholic liquid from which genuine malt vinegar is made is derived 
from the wort obtained by mashing malt, or a mixture of malt and cereals. 
Sugar and glucose vinegar are prepared by the alcoholic and acetic fermen- 
tation of diluted molasses, or other sugar by-product, and glucose respec- 
tively. Spirit vinegar is derived from diluted whiskey, brandy, or alcohol. 

* Tolman and Hartman, Jour. Ind. Eng. Chem., 9, 1917, p. 759. 

t Anderson, Tech. Quart., 6, 1914, p. 214. 

t Farnstainer, Zeits Unters. Nahr. Genussm, 2, 1899, p. 198; 15, 1908, p. 321; Browne, 
Jour. Amer. Chem. Soc, 25, 1903, p. 29; Pastureau, Jour, pharm. chim., 21, 1905, p. 593; 
Balcom, Jour. Amer. Chem. Soc, 39, 1917, p. 309. 

§ Crawford, Jour. Ind. Eng. Chem., 5, 1913; p. 846; Rowatt, Lab. Int. Rev. Dept. 
Canada, Bui. 64, 191 7. 



790 



FOOD INSPECTION AND ANALYSIS. 



Characteristics and Composition of the Various Vinegars. 

^ Cider Vinegar is brownish yellow in color, and possesses an odor of 
apples. It is chiefly distinguished from other vinegar by the presence 
of more or less malic acid, by the character of its sugars, and by the pre- 
dominance of potash in the ash. Its specific gravity varies from 1.013 
to 1.015. Its acidity varies from 3 to 6 per cent, and its solids from i^ to 
3 per cent. Cider vinegar under polarized light is always laevorotatory. 

The following are summarized data of analyses made by H. C. Lyth- 
goe in the writer's laboratory of twenty-two samples of cider vinegar of 
known purity. 





Acetic 
Acid. 


Total 
Solids. 


Ash. 


Alkalin- 
ity of 
Ash.i 


P20sin Ash of loo 
Grams Vinegar. 




Soluble Insoluble 
(mgr.). 1 (mgr.). 


Maximum 


5-86 
3-92 
4.84 


3.20 
1.84 
2-49 


0.42 
0.20 
0-34 


36.1 
22.2 
29.7 


•?1 .7 ' -JT _ c 


Minimum 


12. 1 
19.2 


6-5 
15.6 


Average 







Reducing Sugars. 


Polariza- 
tion, 
Degrees 
Ventzke 
200-nini. 
Tube. 


Malic 
Acid. 


Per Cent 
Ash in 
Total 
Solids. 


Per Cent 
Reducing 

Sugars 
in Total 

Solids. 


Ratio of 

Soluble 

to Total 

P2O5. 


Alkalin- 
ity of 




Before 
Inversion. 


After 
Inversion. 


I Gram of 
Ash, cc. 

— Acid. 
10 


Maximum 

Minimum. 

Average 


0-51 
0-15 
0.25 


0-53 
0-15 
0.25 


-3-6 
-0-3 
-1-3 


0.16 
0.08 
O.II 


19.0 
10. 
13.8 


16.6 

7-3 
10.7 


66.9 

50.0 
56-3 


125.0 
69.0 
90.0 



1 Number of cubic centimeters of tenth-normal acid to neutralize the ash of loo grams of vinegar. 

Twenty-two samples of pure cider vinegar were analyzed by A. W. 
Smith* with the following results: 





Acetic 
Acid. 


Total 
Solids. 


AcV, Alkalinity 
^^^- i of Ash.' 


SoluWe 
P2O5. 


Insoluble 
P2O5. 


Total 
P2O5. 




7.61 

3-24 
4.46 


4-45 
2.00 
2.83 


0.51 
0.31 
0-39 


55-2 
28.4 
38.8 


22.7 
13.6 
19. 1 


19.4 
4-2 

10. 1 


39-0 
19.8 
28.6 


Minimum 


Average 







' Number of cubic centimeters of tenth-normal acid required to neutralize the ash from loo grams 
of vinegar. 

Van Slyke,t in extensive experiments on the home manufacture of 
vinegar, found that the fixed acid in seventeen samples of fresh apple juice 

* Jour. Am. Cham. Soc, 20 (1898), p. 6. 
t N. Y. Agr. Exp. Sta., Bui. 258, 1904. 



VINEGAR. 791 

was 0.55 per cent; after six months it was reduced to 0.39 per cent, after 
eight months to 0.13 per cent, after fifteen months to 0.06 per cent and after 
twenty-four months to 0.02 per cent, the greatest loss being after the alcoholic 
fermentation had ceased and before the acetic fermentation was consider- 
able. 

Tolman and Goodnow * have shown that vinegar made in the tank 
type of generator differs little in composition from that of the hard cider 
except for conversion of alcohol into acetic acid, a marked loss in fixed 
acids, and a gain in pentosans. For example, in one experiment the hard 
cider contained 0.15 per cent of fixed acids and 0.15 per cent of pentosans, 
whereas the vinegar contained 0.06 per cent of fixed acids and 0.19 per 
cent of pentosans. In another experiment the percentages in the hard 
cider were 0.19 and 0.12 and in the vinegar 0.06 and 0.18 per cent respec- 
tively. 

Hartman and Tolman, f from experiments carried out with the rotating 
generator process extending through two years, concluded: (i) During 
fermentation a large part of the malic acid of the apple juice is destroyed 
to form lactic acid. (2) During acetification the remaining malic acid 
is almost entirely oxidized. (3) The fixed acid in the vinegar is chiefly 
lactic acid. 

In the final vinegar made from a mixture of first and second pressings 
they obtained, among other results, in the filtered and cleared stock 
respectively as follows: solids 1.31 and 1.21, non-sugar solids 1.19 and i.io, 
volatile acid as acetic 6.44 and 6.58, malic acid 0.0335 and 0.0440, suc- 
cinic acid 0.0085 and o.oiio, lactic acid 0.225 and 0.285, formic acid 0.0004 
and 0.0004, and acetates as acetic acid 0.043 ^^^ o-039 P^r cent. 

Bender J found that the glycerol content of cider vinegar made by the 
generator process in New Jersey ranged from 0.25 to 0.45 per cent. Good- 
now I found the range for generator vinegar produced in Michigan and New 
York to be 0.24 to 0.46 and 0.25 to 0.31 per cent respectively. Both 
investigators made daily tests for several months of both the cider stock 
and the finished vinegar. 

The composition of cider vinegar ash is found by Doolittle and Hess § 
to be as follows: 



* Jour. Ind. Eng. Chem., 5, 1913, p. 928. 

t Ibid., 9, 1917, p. 759- 

t U. S. Dept. of Agric. Notice of Judgment No. 1159. 

§ Jour. Amer. Chem. Soc, 22, 1900, p. 220. 



792 FOOD INSPECTION AND ANALYSIS. 

Calcium oxide CaO 3-4 to 8.21 

Magnesium oxide MgO 1.88 to 3.44 

Potassium oxide K2O 46.33 to 65.64 

Sodium oxide Na20 None 

Sulphuric anhydride SO3 4.66 to 16.29 

Phosphoric anhydride P2O5 3 . 29 to 6.66 

Iron oxide Fe203 None to trace 

CO2 and loss . . . 0.00 to 40.44 

Wine Vinegar is light yellow if made from white wine, and red if from 
red wine. The former is the highest prized. Wine vinegar varies in specific 
gravity from 1.0129 to 1.02 13, and contains from 6 to 9 per cent of acetic 
acid. It is characterized chiefly by the bitartrate of potassium (cream 
of tartar) which true wine vinegar always possesses. Free tartaric acid 
is also usually present. Wine vinegar is the principal vinegar of France 
and Germany. In the United States the term white wine vinegar is 
usually applied to distilled or spirit vinegar, which is much cheaper than 
the real wine vinegar and altogether inferior to it. 

Wine vinegar is slightly laevo-rotary with polarized light. 

The composition of genuine white wine vinegar is shown by the follow- 
ing summary of the analyses of twenty-two samples, made in the Municipal 
Laboratory of Paris: 



specific 
Gravity. 


Total 
Solids. 


Sugar. 


Bitartrate 

of Potash. 


Ash. 


Acidity 
(as Acetic). 


Maximum 1-0213 

Minimum 1.0129 

Mean i-oi7S 


3-19 
1-38 
1-93 


0.46 
0.06 
0.22 


0.36 
0.07 
0.17 


0.69 
0.16 
0.32 


7-38 
4-44 
7.38 



Weigmann gives the following average of analyses of red wine vinegar: 



Specific 
Gravity. 


Acetic 
Acid. 


Total 

Tartaric 

Acid. 


Free 

Tartaric 

Acid. 


Cream of 
Tartar. 


Alcohol. 


Extract. 


Gly- 
cerin. 


Ash. 


Phos- 
phoric 
Acid. 


I. 0143 


7-79 


0.216 


0.006 


0.057 


1. 19 


0.863 


0.141 


O.I18 


0.012 



Malt or Beer Vinegar is of a brown color, and its odor is suggestive 
of sour beer. It varies in specific gravity from 1.015 to 1.025; its acidity 
is about the same as cider vinegar, but the extract is much larger, varying 
from 4 to 6 per cent. Malt vinegar contains considerable nitrogenous 



VINEGAR. 



793 



matter, and notable quantities of phosphates, dextrin, and maltose. It 
ontains no cream of tartar. Malt vinegar is largely used in Great 
Britain. 

Hehner gives the following data of the analyses of seven samples of 
vinegar undoubtedly made from malt only: * 





Acidity. 


1 
Total 1 A..^ 
Solids. [ ^^'^■ 

1 


Phosphoric 

Anhydride. 


Alkalinity 
(Na2C03). 


Maximum 

Minimum 

Mean 


6.48 
2.88 
4-23 


4-23 
1.68 
2.70 


0.47 
0.22 
0-34 


•13 

.067 

.105 


.089 
.017 
.024 



Allen gives the results of the analyses of three samples of genuine 
vinegar brewed from a mixture of malted and unmalted barley as follows:! 





Specific 
Gravity. 


Acetic 
Acid. 


lotal 
Solids. 


A^^- ""ista' 


Phos- 
phoric 
Acid. 


Nitrogen. 


Albumin- 
oids. 


I 


I. 0170 
1.0228 
I. 0160 


6-39 
5.26 
4.86 


2.67 
3-96 
2.31 


0.34 
0.40 
0.47 


0.091 
0.118 


0.077 
0.093 
0.057 


.099 

•09s 
.099 


.624 


2 


•598 


■I... 


.624 







Wyatt and Schlichting | consider the U. S. limit for phosphoric acid in 
the soluble ash (page 804) too high and have shown that malt vinegar is 
often laevorotatory. A shipment of malt vinegar pronounced an imitation by 
the United States authorities analyzed, according to Wyatt and Schlichting, 
as follows: sp.gr. at 60° F. 1.0164, acetic acid 4.65, lactic acid 0.47, total 
acidity calculated as acetic 4.97, total solids 2.03, dextrin trace, ash 0.46, 
alkalinity of ash (K2O) 0.06, phosphoric acid 0.08, protein (Nx6.25)o.5o, 
opticity (angular degrees, 200 mm. tube) -0.307. Chapman confirmed their 
findings. Russell and Hodgson further criticise the United States Stand- 
ards as permitting sophistication. They propose a minimum of 0.05 per 
cent for phosphoric acid; in authentic samples they found a range of 
0.047 to 0.092 per cent. 



* Analyst, 16, p. 82. See also Analyst, 18, p. 240. 

t Ibid., 19, p. 15. 

X Eighth Int. Cong. App. Chem., 14, 191 2, p. 277. 



794 



FOOD INSPECTION AND ANALYSIS. 



Distilled, Spirit, or Alcohol Vinegar. — This vinegar, being made from 
diluted alcohol, is nearly colorless, unless artificially colored, as it often 
is, with caramel. As stated on page 792, the " white wine " vinegar 
(incorrectly so-called) commonly sold in the United States is of this class. 
Its specific gravity ranges from 1.008 to -1.013. Spirit vinegar contains 
from 3 to ID per cent of acetic acid. Its content of total solids is insig- 
nificant, and it contains only traces of ash. It always contains non- 
acetified alcohol and aldehyde. It has no optical activity with polarized 
light. 

Twelve samples of distilled vinegar analyzed in the Municipal Labora- 
tory of Paris gave according to Girard * the following results: 





Specific 
Gravity. 


Total 
Solids. 


Sugar. 


Ash. 


J 
Acidity. J 


Maximum 

Minimum 

Average 


I.OI31 
1.0082 
I .0100 


0.58 
0. 16 
0.35 


Trace 


.09 
Trace 

.04 


7.98 
4.98 
6.34 



An analysis of a sample of typical distilled or spirit vinegar as produced 
in the United States is given in the table on page 806. 

Glucose Vinegar is made from the acetificalion of alcohol, obtained 
from the fermentation of commercial glucose. This vinegar usually 
possesses the odor and taste of fermented starch. It is low in total solids, 
the extract consisting almost entirely of untransformed glucose, and the 
vinegar therefrom contains all the ingredients of the product from which 
it was made, viz., dextrin, maltose, and dextrose, as well as chloride of 
sodium. It is decidedly dextro-rotatory with polarized light bodi before 
and after inversion. 

Molasses Vinegar. — This is largely the product of the acetic fermen- 
tation of sugar-house wastes, and sometimes of the accidental acetic 
fermentation of molasses itself, after it has undergone alcoholic fermenta- 
tion for the manufacture of rum. This variety of vinegar is sometimes 
used as an adulterant of cider vinegar. With polarized light molasses 
vinegar is dextrorotatory before, and lasvorotatory after inversion. 



Analyse des matieres alimentaires, Paris, 1904, p. 271. 



VINEGAR. 795 

Wood Vinegar is prepared by the purification of pyroligneous acid, 
which may be accomplished by saturating the crude acid wi.h lime or soda, 
adding hydrochloric or sulphuric acid, and distilling. It is further purified 
by redistillation with potassium bichromate, and filtration through bone- 
black. Acetic acid is sometimes added to impart flavor. 

The extract and ash of wood vinegar are very small. Its specific 
gravity averages 1.007 according to Blyth. Empyreumatic or tarry 
products are nearly always present in vinegar of this class. 

ANALYSIS OF VINEGAR. 

Specific Gravity. — This is obtained either with the hydrometer, pyc- 
nomelcr, or Westphal balance. 

Determination of Total Solids.— Weigh 10 grams of the sample in a 
tared platinum dish 50 mm. in diameter, evaporate to dryness on a boiling- 
water bath and dry for two and one-half hours in a water oven at the tem- 
perature of boiling water. Cool in a desiccator and weigh. 

Determination of Ash. — Transfer the dish containing the last residue 
or extract to a muffle, and burn at a low red heat to an ash, or the ignition 
may be accomplished with care over a direct flame turned low. Cool 
ihe dish and weigh. 

Determination of Solubility and Alkalinity of the Ash. — SmilK's 
Method.'^ — Twenty-five cc. of the vinegar are evaporated to dryness in 
a tared platinum dish, ignited, cooled, and the ash weighed. The ash is 
then repeatedly extracted with hot water by washing into a Gooch crucible 
provided with a layer of asbestos (previously ignited in the crucible, cooled, 
and weighed) or upon an ash-free filter. Dry the Gooch or filter, ignite, 
cool, and weigh the insoluble ash. The aqueous extract is titrated directly 
with tenth-normal acid, using methyl orange as an indicator, or treated 
by adding an excess of tenth-normal hydrochloric acid, boiling and titrat- 
ing back with tenth-normal sodium hydroxide, using phenolphthalein. 
Express the alkalinity in terms of 100 grams of the vinegar, by multiplying 
by 4 the number of cubic centimeters of acid required to neutralize. 

Determination of Phosphoric Acid.f — Extract repeatedly the insoluble 
ash as obtained in the preceding section with hot water acidulated with 
nitric acid, and acidify with nitric acid the neutralized solution of the 



* Jour. Amer. Chem. Soc, 20, p. 5. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 46, p. 12. 



796 FOOD INSPECTION AND ANALYSIS. 

soluble ash. Add to each solution 15 grams of ammonium nitrate, heat 
to boiling, and precipitate the phosphoric acid with 50 cc. of ammonium 
molybdate reagent after which digest for an hour at a temperature of 
about 65°, filter, and wash with cold water. Dissolve the precipitate on 
the iilter with ammonia and hot water, and wash into a beaker to a bulk 
of not more than 100 cc. Nearly neutralize with hydrochloric acid, cool, 
and add slowly magnesia mixture (prepared as usual), drop by drop while 
stirring vigorously. After fifteen minutes add 30 cc. of ammonia (specific 
gravity 0.96), let stand for at least two hours, filter on a Gooch crucible, 
wash with 2.5% ammonia till practically free from chlorides, ignite, and 
weigh as Mg2P207. Express results in terms of milligrams of phosphoric 
anhydride in the soluble and insoluble vinegar ash from 100 cc. of 
vinegar. 

Phosphoric acid in the soluble and insoluble ash may be conveniently 
determined also by the uranium acetate method, page 757. 

Determination of Nitrogen. — Concentrate from 50 to 100 cc. of 
vinegar to a syrupy consistency, and proceed as directed under the 
Kjeldahl or Gunning method, page 58. 

Determination of Total Acidity. — Six cc. of vinegar are carefully 
measured from a pipette into a white porcelain dish and diluted with 
water. Using phenolphthalein as an indicator, titrate with tenth-normal 
sodium hydroxide. The number of cubic centimeters of the latter required 
to neutralize, divided by 10, expresses the acidity in terms of percentage 
of acetic acid. 

Approximate Determination of Vinegar Acidity by Lime Water. — It 
has generally been considered difficult for vinegar dealers and others 
who desire to estimate the acidity of their vinegar to do this themselves, 
in that it has been necessary to obtain for the purpose a carefully standard- 
ized alkaline solution, the exact strength of which it is impossible for 
them to determine. 

It has been found that very satisfactory, though of course not abso- 
lutely accurate, results may be obtained by the use of ordinary lime 
water, which any one may easily prepare by making a saturated solution 
of ordinary air-slaked lime. The strength of such a solution is very nearly 
constant, and has been found to be about -g-yVf of the normal. If, there- 
fore, it is not easy to obtain exactly normal or tenth-normal alkali, approx- 
imate figures may be obtained by employing such a saturated lime water. 
If 2.75 cc. of vinegar are titrated with lime water contained in a burette, 
using phenolphthalein as an indicator, the number of cubic centimeters 



VINEGAR. 797 

of the lime water necessary to neutralize the vinegar, divided by lo, 
gives the percentage of acetic acid in the vinegar. To make sure that 
the lime water is saturated, an excess of lime should always be present 
in the reagent bottle. 

Determination of Volatile and Fixed Acids. — Thirty cc. of the vine- 
gar are transferred to a distilling-flask and subjected to distillation, using 
a current of steam. Receive the distillate in a 25-cc. graduated cylinder. 
After 15 cc. have passed over, test from time to time the drops of 
distillate as they fall into the receiving vessel with litmus-paper, and when 
free from acid discontinue the distillation. Note the volume of the 
distillate, mix by shaking, and transfer one-fifth to a white porcelain dish. 
Titrate as in the case of total acidity, expressing the volatile acids as 
acetic. 

Calculate the fixed acid, expressed in the case of cider vinegar as 
malic, by subtracting the percentage of volatile acid from the percentage 
of total acid, and multiplying the result by the factor 1.117. In the case 
of wine vinegar, express as tartaric acid by using the factor 1.25. To 
express acidity in terms of sulphuric acid, multiply the percentage of 
acetic acid by 0.817. 

Determination of Alcohol. — Alcohol is present in very small amounts 
in fruit vinegar that has not been completely acetified. Frear recom- 
mends concentrating the distillates as follows: Neutralize 100 cc. of 
the sample and distill off 40 cc. Then redistill the distillate till 20 cc. 
have gone over. Cool to 15.6° C. and make up to 20 cc. with distilled 
water. Determine the specific gravity with a lo-cc. pycnometer, and 
ascertain from the table on page 690 the per cent by weight of alcohol 
corresponding to the specific gravity. The percentage in the last distil- 
late, divided by 5, expresses the amount of alcohol in the vinegar. 

Detection of Free Mineral Acids. — The ash of genuine cider vinegar 
is always alkaline. If the ash is neutral, free mineral acids are doubtless 
present. For their detection the following is a modification of Brannt's 
method of procedure: 

Add to 50 cc. of the vinegar in an Erlenmeyer flask a small bit of 
starch the size of a wheat-grain, and shake to disseminate it through the 
fluid. Boil for some minutes, cool, and add a drop of iodine solution. 
If a blue coloration occurs, no mineral acid is present. In the presence 
of an appreciable amount of mineral acid, the starch will be converted 
to dextrin and sugar, and no coloration will be produced by the iodine. 

Freafs Method-. — Add 5 or 10 cc. of water to 5 cc. of the vinegar, and 



798] FOOD INSPECTION AND ANALYSIS. 

to the mixture add a few drops of a solution of methyl violet (one part 
of methyl violet 2B in 100,000 parts of water). In the presence of mineral 
acids, a blue or green coloration will be produced. 

Determination of Free Mineral Acids. — Hehner''s Method*— To a 
weighed quantity of the sample add an excess of decinormal alkali, evap- 
orate to dryness, incinerate, and titrate the ash with decinormal acid. 
The difference between the number of cubic centimeters' of alkali added 
in the first place, and the number of cubic centimeters needed to titrate 
the ash, represents the equivalent of the free acid present. 

Detection and Determination of Sulphuric Acid. — This is determined 
as barium sulphate by the addition of barium chloride solution. A slight 
cloudiness on the addition of the reagent indicates the presence cf 
small quantities of sulphate as an impurity, rather than free sulphuric 
acid. If a minute quantity of free sulphuric acid be present, a rather 
heavy white cloud on the addition of the barium chloride will be formed, 
which slowly settles out. According to Brannt, if the quantity of sul- 
phuric acid is more than one part in a thousand, the sulphate of barium 
formed by addition of the reagent produces a copious precipitate that 
rapidly falls to the bottom of the receptacle. This may be filtered, 
washed, ignited, and weighed in the usual manner. 

Detection of Free Hydrochloric Acid. — Distill off half of a measured 
volume of vinegar into the receiving-flask of a distillation apparatus, 
and to the distillate add a few drops of nitrate of silver reagent. A pre- 
cipitate indicates hvdrochloric acid. 

Detection of Malic Acid (Free or Combined). — Absence of malic acid 
may be assured, if no precipitate occurs with neutral acetate of lead, 
when a few drops of a solution of this reagent are added to the vinegar. 
In the presence of malic acid, as in the case of a pure cider vinegar, the 
precipitate which is formed with lead acetate is flocculent, forms at once, 
and is of considerable amount. In pure cider vinegar the precipitate 
will settle to the bottom of the test-tube, leaving a clear supernatant 
liquid within ten minutes. Unfortunately the acetate of lead test is 
a negative one, in that several organic acids other than malic will cause 
a precipitate, as, for instance, tartaric and saccharic acids, the former 
being found in wine and the latter in molasses vinegar. Malt vinegar 
also gives a copious precipitate with lead acetate, due to phosphoric acid. 

The writer employs the following test f for detecting malic acid in 

* Analyst, i, 1877, p. 105. 

t A.n. Rep. Mass. State Board of Health, 1902, p. 485. Food and Drug Reprint, p. 33. 



VINEGAR. 799 

vinegar : Add a few drops of a io% solution of calcium chloride to some 
of the vinegar in a test-tube, and make the mixture slightly alkaline with 
ammonia. Filter off the precipitate that occurs at this point, to the 
filtrate add two or three volumes of 95% alcohol, and heat to boiling. 
A copious, flocculent precipitate of calcium malate will form, if malic 
acid be present, settling to the bottom of the tube in a few minutes. 
A precipitate will occur in malt and glucose vinegar, due to dextrin. 

To confirm the presence of malic acid, filter, wash the precipitate 
with a little alcohol, dry, dissolve it in strong nitric acid in a porcelain 
evaporating-dish, and evaporate to diyness over the water-bath, forming 
calcium oxalate. Boil the residue with sodium carbonate, filter, acidify 
the filtrate with acetic acid, boil to expel the carbon dioxide, and add a 
solution of calcium sulphate. A precipitate of calcium oxalate confirms 
the presence of malic acid. 

The quantitative determination of malic acid is seldom necessary. 

Lead Precipitate. — Hortvet Number. — The quantitative measurement 
of the precipitate formed with lead acetate, or subacetate, is of con- 
siderable importance. Even though the precipitate formed may not be 
due as was long thought to malic acid, but may be due to phosphoric 
acid (though this has not been fully proved), it nevertheless remains a 
fact that the qualitative lead acetate test is one of the most important 
of all in judging the purity of cider vinegar. 

The lead precipitate is best measured as follows: To 25 cc. of the 
vinegar add 2.5 cc. of U. S. P. subacetate of lead solution. Shake and 
whirl in a graduated Hortvet tube in the centrifugal machine, and read 
the volume of the precipitate in the bottom of the tube. The results 
expressed in cc. on thirty samples of pure cider vinegar are summarized 
as follows: Highest, 1.4; lowest, 0.5; average, 0.84. The Hortvet number 
of adulterated cider vinegar runs from a mere trace to 0.5 and some- 
times higher. 

WintoTi's Lead Number. — This is determined by the method de- 
.scribed for maple products, page 658. 

Bailey* obtained by this method the following results: 

Cider vinegar (8 samples) o-o75 to 0.290 

Malt vinegar (3 samples) o. 158 to o. 548 

Distilled vinegar (i sample) 0.018 



*A. O. A. C. Proc, 1908. U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 27. 



800 FOOD INSPECTION AND ANALYSIS. 

Hickey * follows the same method, except that he employs only 5 cc. 
of standard lead subacetate solution and determines the lead in 50 cc. 
of the filtrate. The lead number found by him in twenty samples of 
cider vinegar varied from 0,076 to 0.166. 

Determination of Acid Tartrate of Potassium. — Berthelot and Fleu- 
rien\s Method.] — Twenty-five cc. of the vinegar are evaporated on the 
water-bath to syrupy consistency, and the residue is dissolved in water 
and made up to its original volume. It is then transferred to a 250-cc. 
Erlenmeyer flask, and 100 cc. of a mixture of equal parts of strong alcohol 
and ether are added, the flask is corked, shaken, and set on ice or in a 
cold place for forty -eight hours. At the end of this time, if a crystalline 
precipitate has gathered, the supernatant liquid is decanted upon a filter, 
and finally the precipitate is washed upon it by a fresh quantity of the 
ether-alcohol mixture, and the washing continued with this reagent till 
practically free from acid. The filter and its contents are then trans- 
ferred to the original flask, and the tartrate is dissolved in boiling water, 
after which the solution is titrated in the same flask with tenth-normal 
sodium hydroxide, using phenolphthalein as an indicator. Multiply 
the number of cubic centimeters of alkali required to neutralize by the 
factor 0.0188, and the quotient expresses the grams of bitartrate of potash 
in the sample. Multiply this by 4 to obtain the percentage present. 

Polarization and Determination of Sugar. — If the vinegar is light- 
colored and quite free from turbidity, it may sometimes be polarized undi- 
luted in the loo-mm. tube. Vinegar may often be sufliciently clarified 
for polarization by filtering twice through the same filter. It is, how- 
ever best to add 10% of basic lead acetate solution, and to filter before 
polarizing, thus removing the malic or tartaric acids which may have a 
slight effect on the polarization. In case of dark-colored or turbid 
samples, add to 50 cc. of the sample 5 cc. of about equal quantities of 
lead subacetate and alumina cream, shake, filter, and polarize in a 2co- 
mm. tube, adding 10% to the reading on account of the dilution. 
The polarization value of the vinegar is conveniently expressed in terms 
of actual direct reading obtained by the undiluted sample in a 200- or 
400-mm. tube. 

If the invert reading is desired for calculation of sucrose or com- 
mercial glucose, subject the sample to inversion with hydrochloric acid 
and heat, as in the case of sugars. 

* Ibid. 

t Girard, Analyse des Matieres Alimentaires, Paris, 1904, p. 144. 



VINEGAR. 



801 



For the determination of sucrose, use Clerget's formula (page 6ii), 
calculating the true direct and invert readings from the direct and invert 
readings of the undiluted vinegar on the basis of the normal weight of 
the sample, by multiplying the obtained readings by 0.26 in the case of the 
Soleil-Ventzke instrument. 

Determination of Reducing Matter before and after Inversion- 
Measure two portions of 25 cc. each into loo-cc. flasks. Dilute one por- 
tion with 25 cc. of water, add 5 cc. of concentrated hydrochloric acid and 
invert in the usual manner. Neutralize both portions with sodium 
hydroxide, clear with normal lead acetate, remove the excess of lead with 
potassium sulphate or carbonate, and make up to the mark. Determine 
reducing sugars in each portion by the Munson and Walker method 
(page 622) and calculate as invert sugar. 

The above method gives the total reducing matters before and after in- 
version. To determine the non- volatile reducing matters evaporate the 25 cc. 
portions to dryness then take up in 50 cc. of water and proceed as described. 
Determination of Pentosans.— Place 100 cc. of the vinegar in a flask, 
add 43 cc. of concentrated hydrochloric acid (sp.gr. 1.19) and proceed as 
described on page 286. 

Determination of Glycerol.— The glycerin is extracted by essentially 
the same process as is used for dry wines (p. 703) and determined by 
the Hehner method modified by Richardson and Jaffe * and Low. These 
processes have been adapted to vinegar analysis by Ross j as follows: 

Standard Solutions.— 1. Strong Bichromate.— Dissolve 74.56 grams 
of dry, recrystalHzed potassium bichromate in water, add 150 cc. concen- 
trated sulphuric acid, cool, make up to 1000 cc. at 20° C, and determine 
the specific gravity at 20720° C; i cc. =0.01 gram glycerin. Accurate 
measurements being difficult owing to changes in room-temperature 
it is w^ll to use weighed amounts of the solution from a weight burette, 
dividing by the specific gravity to obtain the volume used. The solution 
has an apparent expansion in glass of 0.0005 (or 0.05%) for each degree 
centigrade. The solution may be measured if this correction is made. 
2. Dilute Bichromate.— Introduce a weighed amount (12.5 times the 
specific gravity) of the strong bichromate from a weight burette into a 
250 cc. glass-stoppered volumetric flask, make up to the mark with water 
at room temperature; 20 cc. = i cc. . of the strong solution. If slightly 
more than 12.5 cc. equivalent is used, make up to the mark and then 
add the required amount of water to make one-twentieth dilution. . 

* Jour. Soc. Chem. Ind., 17, 1898, p. 33°- 

t Proc. A. O. A. C, 1910. U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 61. 



802 FOOD INSPECTION AND ANALYSIS. 

3. Ferrous Ammonium Sulphate. — Dissolve 30 grams of the crystallized 
salt in water, add 50 cc. of concentrated sulphuric acid, cool and dilute 
to 1000 cc. at room temperature; i cc. = approximately i cc. of the dilute 
bichromate. Owing to daily changes in strength it should be standardized 
against the bichromate whenever used. 

Extraction of Glycerol. — Make all evaporations on a water-bath kept 
-it 85° to 90° C. Evaporate 100 cc. of the vinegar to about 5 cc, add 20 cc. 
of water and again evaporate to about 5 cc. to expel acetic acid. Add 
about 5 grams of fine sand and 15 cc. of milk' of lime (freshly prepared 
and containing about 15% of calcium oxide), and evaporate nearly, 
but not quite, to dryness, with frequent stirring, avoiding formation of 
dry crust. Rub into a homogeneous paste with 5 cc. of hot water, add 45 
cc. of absolute alcohol, washing down paste adhering to the sides of the 
dish, and stir thoroughly. Heat the mixture on a water-bath with con- 
stant stirring to incipient boiling, decant onto a 12.5 cm. fluted filter, 
wash twice by decantation and finally on the filter with 90% alcohol 
up to about 150 cc, or, instead of filtering, centrifuge and wash three 
times. Evaporate to a sirup, dissolve in 10 cc. of absolute alcohol, and 
wash into a 50 cc. glass-stoppered cylinder with two 5 cc. portions of abso- 
lute alcohol. Add three portions of 10 cc. each of absolute ether, thor- 
oughly shaking after each addition. Let stand until clear, then pour off 
through a filter, and .wash the cylinder and filter with mixed absolute 
alcohol and absolute ether (1:1.5). If a heavy precipitate is observed 
in the cylinder, it is well to centrifuge at low speed and decant the clear 
liquid through a filter. Add 20 cc of the mixture of absolute alcohol 
and absolute ether to the precipitate in the cylinder, shake thoroughly, 
centrifuge and decant, repeating three times. Evaporate filtrate and 
washings at 85°-9o° C, to about 5 cc. ; dilute and evaporate to 5 cc. 
three times, using respectively 20, 20 and 10 cc. of water. Wash residue 
with hot water into a 50 cc volumetric flask, cool, add silver carbonate 
freshly precipitated from o.i gram of silver sulphate, shake occasionally, 
and allow to stand 10 minutes; then add 0.5 cc. of lead subacetate solu- 
tion, shake occasionally, and allow to stand 10 minutes. Make up to 
the mark, shake well, filter, rejecting the first portion of the filtrate, and 
pipette off 25 cc. of the clear filtrate into a 250 cc. glass-stoppered volumetric 
flask. Precipitate the excess of lead with i cc. of concentrated sulphuric 
acid, and determine the glycerol by the following method : 

Determination. — From a weight burette introduce into the 250 cc. 
flask, containing the 25 cc. of purified glycerol solution, a weighed amount 
of the strong bichromate solution (with ordinary vinegar 30-35 cc.) suf- 



VINEGAR. 803 

ficient to leave about 12.5 in excess, carefully add 24 cc. of concentrated 
sulphuric acid, rotating gently to mix and avoid ebullition, then heat in 
boiling-water bath for exactly 20 minutes. Dilute at once, cool, and make 
up to mark at room temperature. The oxidation is a trifle more complete 
if only 15 cc. of concentrated sulphuric acid are added and the digestion 
is continued for at least 2 hours. 

Standardize the ferrous ammonium sulphate solution against the 
dilute bichromate by introducing from burettes approximately 20 cc. of 
each into a beaker containing 100 cc. of water. Complete the titration, 
using potassium ferricyanide solution (0.5 to 1%) as indicator on a 
porcelain spot plate. Calculate the volume {F) of ferrous ammonium 
sulphate equivalent to 20 cc. of the dilute and, consequently, to i cc. of 
the strong bichromate solution. 

Substitute for the dilute bichromate a burette containing the oxidized 
glycerol with excess of bichromate solution, and ascertain how many cubic 
centimeters of it are equivalent to F cc. of the ferrous ammonium sulphate 
solution, and therefore to i cc. of the strong bichromate. Then 250 divided 
by this last equivalent equals the number of cubic centimeters excess of the 
strong bichromate present in the 250 cc. flask after oxidation of the glycerol. 

The number of cubic centimeters of strong bichromate added, minus 
the excess found after oxidation, multiplied by o.oi equals the weight of 
glycerol in the 25 cc. of purified solution used in the determination; this 
result, multipHed by 2, gives the weight of glycerol in grams per 100 cc. 
of the vinegar. 

ADULTERATION OF VINEGAR. 

Standards of Purity.— In England, where the principal vinegar is 
malt vinegar, the legal standards are considerably different from those in 
force in France and Germany, where wine vinegar is prevalent. These 
differ agam from the requirements found in the United States and Can- 
ada, where cider vinegar is the chief product. 

Some of the state food laws fix a standard for the acidity of cider 
vinegar varying from 3.5 to 4.5 per cent of acetic acid, and in most cases 
also a minimum standard for total solids or residue of from 1.5 to 2 per 
cent. Special laws stipulate furthermore in some states that cider vine- 
gar, sold as such, must be exclusively the product of pure apple cider. 

Following are the U. S. standards for the various vinegars: 

Vinegar, Cider Vinegar, Apple Vinegar, is the product made by the 
alcoholic and subsequent acetous fermentations of the juice of apples, 
is Iffivo-rotatory, and contains not less than 4 grams of acetic acid, not 



804 FOOD INSPECTION AND ANALYSIS 

less than 1.6 grams of apple solids, of which not more than 50% are 
reducing sugars, and not less than 0.25 gram of apple ash in 
100 cc. (20° C.) ; and the water-soluble ash from 100 cc. (20° C.) of 
the vinegar contains not less than 10 milligrams of phosphoric acid 
(P2O5), and requires not less than 30 cc of decinormal acid to neutralize 
its alkahnity. 

Wine Vinegar, Grape Vinegar, is the product made by the alcoholic 
and subsequent acetous fermentations of the juice of grapes, and con- 
tains in 100 cc. (20° C), not less than 4 grams of acetic acid, not less 
than i.o gram of grape solids, and not less than 0.13 gram ot graps ash. 

Ma// Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations, without distillation, of an infusion of barley malt, 
or cereals whose starch has been converted by malt, is dextro-rotatory, 
and contains, in 100 cc, (20° C), not less than 4 grams of acetic acid, 
not less than 2 grams of solids, and not less than 0.2 gram of ash; and 
the water-soluble ash from 100 cc. (20° C), of the vinegar contains not 
less than 9 milligrams of phosphoric acid (P2O5), and requires not less 
than 4 cc. of decinormal acid to neutralize its alkalinity. 

Sugar Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations of solutions of sugar, syrup, molasses, or refiners' 
syrup, and contains, in 100 cc. (20° C), not less than 4 grams of acetic 
acid. 

Glucose Vinegar is the product made by the alcoholic and subsequent 
acetous fermentations of solutions of starch sugar or glucose, is dextro- 
rotatory, and contains, in 100 cc (20° C), not less than 4 grams of acetic 
acid. 

Spirit Vinegar, Distilled Vinegar, Grain Vinegar, is the product made 
by the acetous fermentation of dilute distilled alcohol, and contains, in 
100 cc. (20° C), not less than 4 grams of acetic acid. 

Accidental Adulteration of vinegar may result in the presence of injuri- 
ous metallic salts, such as of copper, lead, or zinc, derived from vessels or 
utensils used in the manufacture of vinegar, or even minute traces of 
arsenic may be found, when glucose has been employed as an ingredient 
or source of the vinegar, the arsenic being in this case probably due to 
impure acid used in the manufacture of the glucose. 

Fraudulent Adulteration may consist merely in diluting cider, malt, 
or wine vinegar to 4 per cent acid strength or less without a declaration 
on the label or in substituting distilled vinegar wholly or in part for the 
more expensive kinds. 



VINEGAR. 803 

Imitation cider vinegar is frequently made up of spirit vinegar, 
colored with caramel, the solids being reinforced by boiled cider or 
apple jelly, made often out of exhausted apple pomace, left after the 
apple stock has been subjected to one and sometimes two pressings. 
Since sweet cider usually contains over ii% of solids and the stand- 
ard for cider vinegar requires only i.6%, it is readily seen how a 
given volume of cider may be made to contribute the normal amount 
of solids to at least seven times that volume of an artificial cider 
vinegar containing distilled vinegar as a^ base. More skilful mixtures 
contain about equal volumes of distilled and cider vinegar with 
sufficient boiled cider and caramel to make up for the deficiency of 
solids and color. To further mislead the analyst soluble mineral matter 
and even glycerin are added. Acetic ether is sometimes used to impart 
flavor. 

The table on p. 806 by Balcom * shows the range in composition of 
authentic vinegars and the influence of dilution with spirit vinegar, 
with and without addition of boiled cider, on the composition. 

Character of the Residue. — The residue of pure cider vinegar should 
be thick, light brown in color, of a viscid or mucilaginous consistency, 
somewhat foamy, having an astringent acid, though pleasant, taste, 
very suggestive of baked apples, which it also resembles in color. The 
residue of malt or beer vinegar is brown and gummy, has a characteristic 
odor and contains a considerable quantity of dextrin. The odor of 
molasses is very apparent in the residue of vinegar from sugar-house 
wastes. If pyroligneous acid or wood vinegar has been introduced, the 
dried residue may have a tarry or smoky taste and smell. 

The residue of cider vinegar is very soluble in alcohol, while that of malt 
vinegar is only slightly soluble. Wine vinegar residues dissolve readily 
in alcohol, except for the granular residue of cream of tartar. If the 
loop of a clean platinum wire be rubbed in the vinegar residue and ignited 
in a colorless Bunsen flame, the color imparted will, if the vinegar has 
been made from pure cider exclusively, consist altogether of the pale- 
lilac color of a potash salt without any of the yellow sodium flame being 
visible. In all vinegars other than of pure cider, the sodium flame will 
predominate, when the residue is burnt as above. Again, the ignited 
residue left in the loop of wire in the case of a pure cider vinegar will 
form a fusible bead, having a strong alkaline reaction upon moistened 



* A. O. A. C. Proc, 1909. U. S. Dept. of. Agric, Bur. of Chem., Bui. 132, p. 93. 



806 



FOOD INSPECTION AND ANALYSIS. 



COMPARISON OF VINEGARS OF KNOWN CHARACTER WITH COMMERCIAL 

SAMPLES. 



Cider Vinegar. . . 

Authen- ,. , " ' 

tic * ^^""^ 
"^ J Min. 

Commercial f . 
Spirit Vinegar. . . 
Mixture At 

" B§ 

" C|l 

Molasses Vinegar, 




* Compilation of lOO analyses. The figures for each constituent represent from s6 to 94 samples, 
t A mixture of 50 samples. All were passed but some were thought to contain a diluent and a few 
probably had been mixed with boiled cider or a similar material. 
t Equal parts of two preceding samples. 

§ Known mixtuFe of cider and spirit vinegars fortified with boiled cider. 
II Commercial sample evidently of same general character as preceding. 

test-paper, and effervescing briskly when immersed in acid. The pres- 
ence in vinegar of even a slight trace of added mineral acid will prevent 
the ignited residue from having the alkaline reaction, or effervescing with 
acid.* 

The odor given off in the first stages of burning this residue to an 
ash should be noted. With cider vinegar the apple odor is very marked 
while burning. In vinegar wherein molasses products have been employed, 
the smell of charred sugar is usually apparent, while with glucose vinegar 
the smell of burnt corn predominates. On burning the residue of malt 
vinegar, the odor produced at first is not unhke that of toasted bread. 
At a later stage in the burning the vapors evolved are very pungent. 

Character of the Ash. — The ash of pure cider and malt vinegar is 
quite strongly alkaline, while that of distilled and wood vinegar is only 
Slightly alkaline. In cider and malt vinegar the quantity of phosphoric 
acid present in the ash is considerable, while only traces are present in 
distilled or spirit vinegar. Considerably more than half the phosphoric 



Davenport, i8th An. Rep., Mass. Board of Health, 1887, p. 159. 



VINEGAR. 807 

acid in the ash of cider vinegar is soluble, while no soluble phosphoric 
acid is present in the ash of spirit vinegar. 

The percentage of ash in total solids is of some value in judging the 
purity of cider vinegar. According to Frear,* if the ash of the vinegar 
is less than io% of the total sohds, the vinegar may be suspected of 
having added unfermented material, while a percentage of ash less than 
6 is absolute evidence that the vinegar is not genuine cider vinegar, 

Balcom f finds that the percentage of ash in the non-sugar solids 
is more constant than in the total solids, since the amount of sugar varies 
greatly in pure vinegar. This figure is of service in detecting the presence 
of mineral matter when added in conjunction with boiled cider in such 
amount as not to disturb the normal ratio of ash to total solids. 

The alkalinity of i gram of the ash of pure cider vinegar should be 
equivalent to at least 65 cc. of tenth-normal acid. At least 50% of the 
phosphates in the ash should be soluble in water. 

Character of the Sugars. — Browne J found that the rotation of the 
freshly expressed juice of eleven varieties of apple varied from —19.24° 
to —49° Ventzke, in a 400-mm. tube. Also that five samples of completely 
fermented cider, examined five or six months after pressing, polarized 
in a 400-mm. tube from —1.76° to —5.28°. He found also that 20 grams 
of a pure cider jelly made from concentrated apple juice diluted to 100 
cc, had a left-handed rotation amounting to 21.35° in a 200-mm. tube, 
and finally that four cider vinegar samples of known purity showed readings 
of from —0.96° to —2.94° Ventzke in a 400-mm. tube. 

The left-handed rotation of pure cider vinegar is a characteristic so 
fixed and unalterable that a right-handed polarization of more than 0.5° 
may safely be assumed as evidsnce of adulteration. The polarization of 
cider vinegar, expressed in terms of 200 mm. of the undiluted sample 
should lie between —0.1° and —4.0° Ventzke. If the direct polarization 
of a sample of vinegar is right-handed, while the invert is left-handed, 
sugar -house wastes or molasses may be suspected as an adulterant. 

If both direct and invert readings are right-handed, commercial 
glucose is undoubtedly present. If the polarization of the vinegar is 
far to the left, boiled cider or apple jelly has probably been used to rein- 
force the solids. 

Frear regards the ratio of reducing sugars after inversion to total 

* Report of Penn. Dept. of Agric, 1898, p. 38. 

t Loc. cit. 

X Bull. 58, Penn. Dept. of Agric, "A Chemical Study of the Apple and Its Products." 



808 



FOOD INSPECTION AND ANALYSIS. 



solids as a useful factor in discriminating between pure cider vinegar 
and the common artificial substitutes in which the solids of distilled vinegar 
are reinforced by apple jelly, or in which glucose or molasses vinegars 
are used. When the reducing sugars after inversion form more than 
25% of the entire solids, the alleged cider vinegar is usually spurious, 
although in exceptional cases it runs up to 45%. In pure cider vinegar 
the per cent of reducing sugar is the same after inversion as before. The 
same is true of glucose \anegar. Vinegar containing added molasses 
or cane sugar will, however, naturally show an increase in reducing sugar 
after inversion. 

A large content of alcohol in cider vinegar, otherwise showing the 
constants of pure vinegar except for the low acidity, would indicate incom- 
plete acetification. A high content of nitrogen is characteristic of malt 
vinegar. 

The table below gives a summary of analyses of eighty-four samples 
of undoubtedly pure cider vinegar examined at the Food and Drug 
Department of the Massachusetts State Board of Health in 1901,* 

CIDER VINEGAR FOUND PURE. 





Acid 
(Per Cent). 


Solids 
(Per Cent). 


Ash. 
(Per Cent). 


Polarization. 


xVlaximum 


6.36 

4-5° 
4.84 


4.00 
2.01 

2.43 


0.58 
0. 19 
0.38 


-S-4 
-0.4 
— 2.0 


Minimum 


Mean 







The table on page 809 includes samples of adulterated vinegar, sold for 
cider vinegar, none of which was probably made from cider. It will 
be noticed that in several of the samples the amount of glucose was 
abnormally large, as is shown by the very high right-handed polarization, 
in one case amounting to over 12°. 

Glycerol is absent in distilled vinegar hence a determination of this 
constituent is a valuable means of detecting distilled vinegar in cider vinegar. 
The limits for pure cider vinegar are given on page 791. 

Direct Tests Made on the Vinegar.— Brannt f applies the test of odor 
in vinegar as determining its character, by rinsing out a large beaker 



*32d An. Rep. (1900), p. 661, Food and Drug Reprint, p. 44; 33d An. Rep. (1901), p. 
467, Food and Drug Reprint, p. 47; 34th An. Rep. (1902), p. 483, Food and Drug Reprint, 

P-3I- 

t A Practical Treatise on the Manufacture of Vinegar, Phila., 1914, p. 231. 



VINEGAR. 



809 



VINEGAR NOT THE EXCLUSIVE PRODUCT OF PURE APPLE CIDER. 



Per Cent 


Per Cent 


Per Cent 


Per Cent 


Polarization 




Acetic Acid. 


Total Solids. 


Ash. 


Ash in Total 
Solids. 


in 200-nim. 
Tube. 


Lead Acetate. 


5-90 


-40 


.... 


.... 


+ 1.4 


No precipitate 


5-14 


-36 




.... 


.0 


" " 


5-12 


■53 


.... 


.... 


+ .6 


" " 


4-83 


3-70 


•32 


8.65 


+ 8.ot 


" " 


4.82 


2.71 


•13 


4.80 


+ 9-6t 


Heavy precipitate* 


4.80 


1.97 


.20 


10.15 


+ -9 


Precipitate 


4.80 


1.03 


.27 


14-75 


+ 1.1 


' ' 


4.66 


2.92 


.20 


6.49 


-f 2.2 


No precipitate 


4.60 


2-57 


.... 


.... 


-f 2.6 


" " 


4-56 


2.60 








+ 7-ot 


t 


4-54 


3-97 


.19 


4-78 


+ 5-6 


No precipitate 


4-54 


3-90 


•32 


9.72 


+ 5-0 


a << 


4-54 


2-94 


•23 


7.82 


+ 5.0 


" " 


4-54 


2.70 


•23 


8.52 


+ -4 


Precipitate 


4-5° 


3-05 







+ 2.2 


No precipitate 


4-50 


2.92 


.22 


7-52 


+ -9 


" " 


4-50 


2.69 


.... 




-f2.8 


" " 


4-48 


3.80 


.... 




+ 12. oX 


It IC 


4.46 


2.80 


.... 




-f 2.6 


< 1 It 


4-42 


2-75 






+ 3-2 


Slight precipitate 


4.42 


2.10 






+ 9-2 


Precipitate 


4-40 


2.51 


.20 


II. 15 


+ I.I 


" 


4.40 


-97 







+ -4 


No precipitate 


4-38 


.29 






+ 1.6 


" " 


4-32 


.70 


.09 


12^86 


.... 


It tt 


4.08 


3-35 






-f 1.2 


Precipitate 


3-98 


-55 







-f 1.8 


Slight precipitate 



* Cider vinegar to which apple jelly containing glucose had been added for the purpose of increas- 
ing the solids after watering. 

t This sample contained a large amount of phosphate, and consequently the test for malates is 
obscured. 

X These samples polarized practically the same after as before inversion, indicating much glucose. 

with the sample, and after allowing it to stand for some hours, examining 
the few drops remaining in the beaker. The acetic acid having for the 
most part become volatilized, the characteristic vinous odor of pure wine 
vinegar would at this stage be very prominent, while that of cider vinegar 
would be entirely different. The odor of the two vinegars is very similar 
in their ordinary state. The peculiar fruity flavor of pure cider vinegar 
is very characteristic and not readily imitated by cheaper substitutes. 
Only a very slight turbidity should be produced in pure cider vinegar 
by the addition of either ammonium oxalate (absence of lime), barium 
chloride (absence of sulphuric acid or sulphate), and nitrate of silver 
(absence of hydrochloric acid or chlorides). 

The character of the precipitate produced by neutral lead acetate 
should be particularly noted. Unless it is ilocculent and copious, set- 



810 FOOD INSPECTION AND ANALYSIS. 

tling out after a few minutes, cider vinegar is not pure, even if a marked 
turbidity is produced. Added apple jelly from exhausted apple pomace 
gives such a turbidity, and is to be suspected when not more than a cloudi- 
ness is produced on addition of the lead acetate reagent. Pure cider 
vinegar usually responds to both the lead acetate and the calcium chloride 
tests for malic acid. Van Slyke,* Browne t and Mestrezat f have shown, 
however, that malic acid decreases during alcoholic fermentation and may 
during the subsequent acetous fermentation disappear largely or entirely. 

"Wood Vinegar or Pyroligneous Acid is sometimes rendered apparent 
by the empyreumatic or tarry taste and odor imparted to the product. 
When, however, the added acetic acid has been so purified that the tarry 
taste and odor are lacking, its presence may often be proved by the traces 
of furfurol which always accompany it. 

Test for Furfural. — A little of the vinegar is subjected to distillation, 
and to the first few drops of the distillate is added a little colorless anilin 
solution. A fading crimson color will be produced in presence of furfurol. 
This reaction may sometimes be obtained upon the vinegar itself without 
distillation, if sufficient added wood vinegar be present. 

The first portion of the distillate of wood vinegar reduces permanga- 
nate of potassium to a marked degree. 

The Addition of Spices to vinegar in order to increase the pungency 
is best detected by first neutralizing the vinegar with sodium carbonate 
and then tasting. Under these conditions, the admixture of spices is 
rendered very apparent. 

Detection of Caramel. — Considerable added caramel in vinegar is 
apparent from the unnaturally dark color and extremely bitter taste of 
the residue after evaporation. 

Tests for caramel made on the vinegar residue, if long dried at the 
temperature of the water-bath, are not to be depended on as establishing 
the presence of added caramel, since at that temperature the decomposi- 
tion of the sugar may in any event cause a positive test. 

Caramel is detected by Crampton and Simon's and Amthor's tests 
(page 784). A further indication of caramel is the reducing power of the 
water solution of the precipitate obtained in Amthor's test. 

Examination for Metallic Impurities. — Lead and Zinc are best looked 
for in the ash of the vinegar in cases where, like cider vinegar, the percent- 

* N. Y. Agr. Exp. Sta., Bui. 258. 

t Penn. Dept. of Agric. Rep., 1901, p. 128. 

X J. Soc. Chem. Ind., 27, 1908, p. 763; 28, 1909, p. 734. 



VINEGAR. 811 

age of extract is high. A large volume of the vinegar is evaporated to 
substantial dryness over the water-bath. This may most readily be 
done in a loo-cc. platinum v^ine-shell, adding the vinegar in successive 
portions. To the residue add a small amount of sodium hydroxide, and 
burn to an ash in a muffle, or over a low flame, using potassium nitrate 
if necessary, a little at a time. Take up the ash in dilute hydrochloric 
acid, and examine for lead and zinc as in the case of canned goods. 

In the case of vinegar low in extract, as in spirit vinegar, the sample 
may be evaporated to dryness, the residue dissolved directly in dilute 
hydrochloric acid without ignition, and the acid solution subjected to 
direct examination for lead and zinc. 

Copper is best determined by electrolysis. loo cc. of the vinegar 
are evaporated to a volume of about lo cc. with a little sulphuric acid, 
filtered into a platinum dish, and subjected to electrolysis, using con 
veniently the apparatus described on page 634. 

Arsenic. — Boil down a portion of the vinegar, to which concentrated 
nitric acid has been added, to a small volume, then add a few cubic centi- 
meters of concentrated sulphuric acid, and continue the heating till fumes 
of sulphuric acid show the nitric to have been driven off. Cool, dilute 
with water, and test in the Marsh apparatus. 



CHAPTER XVII. 
ARTIFICIAL FOOD COLORS. 

The use of artificial dyestuffs in food products has greatly increased 
during recent years, both in degree and in variety of colors employed. 
Where formerly but a few well-known coloring matters, chiefly so-called 
vegetable colors and occasionally mineral pigments were used for this 
purpose, a vast array of dyes, chosen largely from the coal-tar colors, 
are now found in food, so that at present the exact identification of the 
particular dyestuff employed oftentimes presents a somewhat formidable 
problem to the analyst. The problem may consist in determining the 
class to which a commercial food color or combination of colors belongs, 
or it may consist in isolating the color itself, and afterwards identifying 
it as far as possible, for the purpose of determining whether or not it is 
harmless within the meaning of the law. 

The effect of imparting to the cheaper varieties of jellies, jams, and 
ketchups which flood the market such intense and striking colors that 
these products in no wise resemble their pure uncolored prototypes, has 
a tendency in many cases to mislead the public into the idea that the 
genuine products are inferior by contrast, and to create a craving for 
unnaturally colored varieties. Indeed, the adherents to the free use of 
coloring matters in food assert that these brilliant hues please the eye and 
are hence legitimate. 

Objectionable Features. — With the exception of confectionery and 
certain dessert preparations, in which dyes may be employed purely for 
aesthetic considerations only (a fact which is well understood by the 
consumer), the use of coloring matters in food is mainly for the purpose 
of deceiving as to their true character. The use of dyestuffs in food 
is objectionable on two accounts, first as introducing in some cases 
materials injurious to health, and second, in nearly all cases as deceiv- 
ing the purchaser by concealing inferiority, or by making the goods 

812 



ARTIFICIAL FOOD COLORS. 813 

appear of greater value than they really are. In most states the food 
laws regarding employment of colors are so framed, that the presence 
of such colors constitutes an offense under one or the other of the above 
heads, mainly, however, because, by reason of their use, cheaper or 
inferior materials are made to masquerade for the higher or genuine 
grades, as, for instance, when alleged currant jelly is found to consist 
chiefly of apple-stock and commercial glucose, colored with an artificial 
red dye. 

In such cases the analyst has merely to prove conclusively that an 
artificial color is present, even if he does not identify the dye itself. It 
is of course more satisfactory to at least show in addition whether the 
dye present is of vegetable origin, or is of the coal-tar variety, and in most 
cases this can readily be done, even if it is not easy to identify the exact 
color. 

In localities where laws prevail stipulating that what are commonly 
known as "mixtures" or "compounds" to be legally sold, must be 
labeled with the names and percentages of ingredients, the law applies to 
coloring matters as well as other ingredients, and it may even be ruled in a 
strict interpretation of the law that the exact dye or dyes employed should 
appear on the label. 

Toxic Effects of Colors. — Formerly the use of such pigments as 
chromate of lead was common in coloring confectionery, but lead 
chromate is rarely used at present. Other mineral pigments obviously 
unfit for use in food by reason of their well-known poisonous effects are 
those which contain salts of arsenic, mercury, lead, and copper. While 
most of the coal-tar colors are considered harmless in themselves, some 
are decidedly objectionable, and should not be used in foods. Under 
the latter class are included, first, those in connection with the manu- 
facture of which arsenic, mercury, or other poisonous mineral ingredients 
have been used, such for example as arsenical fuchsin, and, second, those 
which are themselves inherently poisonous, as for instance picric acid. 
Fuchsin is now largely made without the aid of arsenic acid, and this 
variety is, perhaps, harmless. The toxic effects of many of the coal-tar 
colors have not been thoroughly established excepting in a negative way. 
Weyl has made many experiments on dogs and rabbits in which these 
animals have been fed with varying amounts of coloring material. In 
nearly all cases the doses far exceeded the amounts ordinarily taken in 
food, and the experiments are of value mainly in so far as they show 
harmless results of certain colors on the animal. It is to be regretted 



814 FOOD INSPECTION AND ANALYSIS. 

that physiological experiments cannot more readily be tried on human 
beings, so as to study the effects of administering to them such amounts 
as are used in food. 

More conclusive results (though still of a negative character) tending 
to establish the harmlessness of most of the coal-tar colors are given by 
Grandhomme * in statistics showing the condition of health of laborers 
in factories where these dyestuffs are made, in comparison with those 
engaged in other industries where poisonous materials are handled. 
From these it appears that the proportion of illness among the anilin- 
makers is remarkably small. 

In the case of coloring confectionery by the use of mineral pigments, 
a considerable amount of the coloring material must be used, forming 
without doubt a source of danger in some cases. With coal-tar dyes, on 
the contrary, the case is different. One ounce of auramine, for instance, 
has been found sufficient to give a deep-yellow color to 2,000 pounds- 
of confectionery, so that almost an infinitesimal amount of the actual 
dyestuff is taken into the system. Hence it is that very little danger 
need be apprehended from the use of most coal-tar colors in food, objec- 
tionable as they certainly are as a commercial fraud. 

Injurious and Non-injurious Colors. — Various countries have enacted 
specific laws regulating the use of coloring matters in foods, especially 
England, France, Germany, Austria, and Italy. In some cases attempts 
have been made to specify harmful and harmless colors. The National 
Confectioners' Association of the United States has compiled a useful 
classified list of injurious and harmless colors, f the classification being 
based largely on the resuUs of experiments by Weyl and others, as well 
as on the Resolutions of the Association of Swiss Chemists, and on the 
French Ordinances regarding food colors. Eight years after the publica- 
tion of this list Hesse | found that thirteen of the twenty-one organic 
dyes listed as harmful were on sale for coloring foods. The list is as follows, 
the names of the individual coal-tar dyes being those in Mathewson's 



* Weyl, Sanitary Relations of the Coal-tar Colors, pp. 28-30. 

t Colors in Confectionery. An Official Circular from the Executive Committee of the 
National Confectioners' Association of the U. S., 1899. 

J Coal-tar colors used in food products, Washington, 191 2. 



ARTIFICIAL FOOD COLORS. 815 

table, (pages 868 and 875) and not in all cases the synonyms given the 
first place in the original list, and the numbers, those assigned in 
Green's English edition of Schultz and Julius' tables * 

Haimful Mineral Colors.— Compounds of mercury, lead, copper, arsenic, 
antimony, tin, zinc, chromium, and barium, and preparations containing 

them. 

Harmful Organic Colors.— Red: Biebrich Scarlet (163), Crocein 
Scarlet (160), New Coccin (106), Crocein Scarlet 8B (169), Crocein 
Scarlet O extra (164), SafTranin (584). Yellow: Gum Gutta, Picric 
Acid (i), Martins Yellow (3), Resorcin Yellow (84), Victoria Yellow 
(2), Orange II (86), Metanil Yellow (95), Sudan I (11), Orange IV (88). 
Green: Naphthol Green B (398). Blue: Methylene Blue (650). Brown: 
Bismarck Brown (197), Bismarck Brown R (201), Fast Brown G (138), 
Chrysoidin (17, 18). 

Harmless Mineral Colors.— Green: Ultramarine Green. Blue: Ultra- 
marine Blue. Violet: Ultramarine Violet. Brown: Manganese Brown, 
Chocolate Brown and similar colors having as their basis natural or pre- 
cipitated iron oxide free from arsenic. 

Harmless Organic Colors.— i?g(/; Cochineal Carmine, Carthamic Acid 
(from saffron), Redwood, Artificial Alizarin and Purpurin (534-537)> 
Cherry and Beet Juices, Eosin (512), Erythrosin B (517)5 Rose Bengal 
(520), Phloxin (521), Ponceau 2 R (55), Ponceau R (55), Bordeaux B 
(65), Cerasin, Ponceau 2 G (15), Acid Magenta (462), Archil Substitute 
(28), Orange I (85), Congo Red (240), Azorubin S (103), Amaranth 
(107), Fast Red E (105), Crocein Orange (13) Fuchsin (448). Yellow and 
Orange: Annatto, Saffron, Safiflower, Turmeric, Naphthol Yellow S (4), 
Brilliant Yellow (5), Crocein Orange (13), Acid Yellow G (8), Acid Yellow 
R (9), Azarin S (70), Orange I (85), Orange GT (43), mixtures of harmless 
red and yellow colors. Green: Spinach Green, Chinese Green, Malachite 
Green (427), Dinitrosoresorcin (394), mixtures of harmless blue and 
yellow colors. Blue: Indigo (689), Litmus, Archil Blue, Gentian Blue 6B 
(437), Coupler's Blue (600), in general such blues as are derived from 
triphenylrosanilin or from diphenylamin. Violet: Methyl Violet (451), 
Wool Black (166), Naphthol Black B (188), Azoblue (287), Mauvein (593), 
Brown: Caramel, Licorice, Chrysamin R (269). 



*A Systematic Survey of the Organic Coloring Matters, founded on the German of 
Schultz and Julius. London, 1908. 



816 FOOD INSPECTION AND ANALYSIS. 



MINERAL COLORS. 

It is impracticable to name all the mineral colors that might be added 
to food, as the list would include all known pigments. Even a list of the 
colors reported in the literature of the past generation as having been 
detected in foods would be of little value owing to changing conditions. 
Fortunately only a few comparatively harmless pigments, such as Prussian 
blue, ultramarine, and iron oxide, are now used to any considerable 
extent and these only in special classes of products. 

The coloring of meat products and saccharine foods with pigments is taken 
up in Chapters VIII and XIV respectively, the facing of tea and coffee, in 
Chapter, XI, and the greening of fruits and vegetables, in Chapter XXI. 

Detection of Mineral Colors. — Still more impracticable than to 

list the possible colors is to give adequate descriptions of methods for their 
detection and for the determination of the elements contained in them, as 
this would cover a wide field in qualitative and quantitative analysis. 

In general it may be stated that the pigments appear as colored particles 
under the microscope and the chief elements occur in the ash prepared with 
special precautions. The pigments may be extracted from some foods by 
acids, alkali solutions, or other solvents, either directly or after evaporation. 

Microscopic examination and microchemical tests of the sediment, 
obtained by shaking or dissolving the sample with water, are useful in the 
case of tea, coffee, sugar, confectionery, etc. Particles of the pigments 
making up the facing of tea may be found by examining the siftings from 
the sample under a lens. 

Special methods for the detection of mineral colors are given in the 
chapters above mentioned; the following tests are for a few colors of 
common occurrence: 

Prussian Blue. — This pigment is insoluble in water. It is decom- 
posed and decolorized by treatment with potassium hydroxide. If the 
filtered alkaline solution of the coloring matter be treated with hydro- 
chloric acid and ferric chloride, a precipitate of the original Prussian 
blue will be produced. 

Ultramarine Blue is decolorized by hydrochloric acid with evolution 
of hydrogen sulphide, which blackens filter-paper moistened with lead 
acetate. Tests for the detection of both ultramarine and Prussian blue 
in tea are described on page 388 and in sugar oh'^page 613. 

Chromate of Lead has never been used to any extent in food products 
with the exception of confectionery. For its detection, see page 678. 



ARTIFICIAL FOOD COLORS. 817 



LAKES. 



Coal-tar Lakes.— Berry * has compiled lists of the coal-tar colors 
combined to form lakes, the mineral and organic substances used in their 
preparation, and the substances mixed with them to modify their color 
or properties. Over fifty dyes are listed but of these few are now used. 
Lakes of acid dyes are prepared chiefly with barium chloride, lead nitrate, 
lead acetate, zinc sulphate, aluminum sulphate, aluminum acetate, 
alums, tin chloride, antimony chloride, tartar emetic, double fluorides of 
antimony and sodium or potassium, calcium nitrate, and calcium acetate; 
those of basic dyes, with tannic acid, sodium phosphate, sodium arsenite, 
stannic and stannous acids and salts, antimony acids, resinic and various 
fatty acids. The principal materials used to modify the colors are barium 
sulphate, kaolin, calcium sulphate, infusorial earth, red lead, zinc oxide, 
lead sulphate, aluminum hydroxide, aluminum arsenite, barium phosphate, 
lead carbonate, calcium phosphate, lampblack and green earth. 

Lakes of Vegetable and Animal Dyes.— The list given by Berry includes 
alum, ammonia, soda, and lime lakes of the following colors: buckthorn, 
Persian berries, yellow berries, quercitron, weld, gamboge, young and 
old fustic, barberry, annatto, turmeric, saffron, safflower, Indian yellow, 
Chinese yellow, cochineal (carmine), lac, dyewoods, indigo sulphonic acid, 
chlorophyl, lokao, and unripe Persian berries. 

Alum lakes, particularly of cochineal, appear to be most used. 

DETECTION OF LAKES.— Like inorganic pigments lakes are insoluble 
in water and therefore under the microscope appear as colored particles. 
The inorganic portion of a lake is tested for in the ash or charred mass, 
the organic portion whether of coal-tar, vegetable, or animal origin, by 
the usual tests after liberation by acid or alkali, according as the original 
color was acid or basic, and separation by dyeing or by immiscible solvents 
as described in subsequent sections. 

VEGETABLE AND ANIMAL COLORS. 

These with a few mineral pigments were formerly almost exclusively 
used for coloring food products, and are still used to some extent. 



* Coloring Matters for Foodstuffs and Methods for their Detection, U. S. Dept. of Agric. 
Bur. of Chem., Circ. 25, p. 7. Jennison, Manufacture of Lake Pigments, 1900. 



818 FOOD INSPECTION AND ANALYSIS. 

Detection of Vegetable and Animal Colors.— Most of the 

soluble red colors of fruits and vegetables, according to L. Robin,* 
react with ammonia to form a coloration, -usually passing from violet to 
blue, then to a brownish green, when the ammonia is added little by little 
in excess to the color in solution while the yellow colors of such fruits as 
apples, peaches, plums, quinces, and apricots, according to Martin- 
Claude,! change to brown with ammonia. 

Dyeing Tests and Reactions on the Fiber. — The natural colors of fruits 
and vegetables in an acid bath (page 841) impart scarcely any color to 
unmordanted wool or silk even by single dyeing. Most of the commercial 
vegetable dye stuffs also do not dye wool without a mordant, at least by 
the double dyeing method, while a few, notably the lichen colors (archil, 
cudbear, and litmus) impart a decided color although by no means of such 
a brilliant hue as many of the coal-tar dyes. Many of these colors dye 
cotton, previously mordanted by boiling in a solution of aluminum acetate 
or potassium bichromate, in a bath acidified with acetic acid. 

Mathewson gives the reactions on the fiber of cochineal (page 855), azo- 
litmin, the dyeing principle of litmus (page 855), and curcumin, the dyeing 
principle of turmeric (page 856). The reactions obtained by Loomis J with 
twenty-one natural dyes fixed on wool or cotton appear in the table on page 
819. In mordanting the fiber Loomis employs the following methods: 

Alum Mordanting. — Dissolve i gram of crystallized aluminum sulphate 
and 1.2 grams of cream of tartar in 500 cc. of water. Stir 10 grams of 
fat-free wool in the solution for one hour, let stand two to three hours, wring, 
and dry at room temperature. 

Tin Mordanting. — Dissolve 0.8 gram of tin crystals and 0.4 gram of 
oxalic acid in 500 cc. of water. Boil 10 grams of fat-free wool one and one- 
half hours in this solution. 

Chrom Mordanting. — Heat to boiling 500 cc. of water containing 10 
grams of fat-free wool, then add 0.2 gram potassium bichromate 0.35 gram 
of cream of tartar, and o.i cc. of concentrated sulphuric acid, and boil one 
and one-half hours. Dry at low temperature and keep from light. 

Extraction by Immiscible Solvent from Various Solutions. — Mathew- 
son, in connection with the table on page 868, makes the following state- 
ments : 



* Girard et Dupre, Analyse des Matieres Alimentaires, Paris, 1894, pp. 678, 679. 

t Jour, pharm. chim., 13, 1901, p. 174. 

X U. S. Dept. of Agric, Bur. of Chem., Circ. 63, pp. 47 and 48. 



ARTIFICIAL FOOD COLORS. 



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820 FOOD INSPECTION AND ANALYSIS. 

Colors of fustic, quercitron, Persian berries after hydrolysis, and alkanet 
are extracted in large part by amyl alcohol and amyl alcohol-gasoline 
(i : i) from N/64 acetic acid or N/64 to N hydrochloric acid, also by ether 
from N/64 hydrochloric acid, but not by amyl alcohol-gasoline or ether 
from N/64 sodium hydroxide solution. Annatto, not alkali treated, 
behaves similarly but is extracted in large part by amyl alcohol-gasoline 
from N/64 sodium hydroxide. 

Colors of barwood, camwood and sandalwood resemble Nos. 483 and 
510 in behavior, but are less soluble in aqueous solvents. They are ex- 
tracted almost completely by amyl alcohol from salt solution and by amyl 
alcohol, amyl alcohol-gasoline, and ether from N/64 hydrochloric acid. 
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hydroxide. Ether extracts the chief part from N but not from 4N hydro- 
chloric acid. The color of Brazil wood is similar but more soluble in 
aqueous solvents. That of logwood is also similar but still more soluble. 
It is nearly all extracted by amyl alcohol from salt solution or N/64 
hydrochloric acid, and the larger part by amyl alcohol-gasoline from 
N/64 hydrochloric acid. Onl)/ the smaller part is extracted by ether 
from N/64 and very little from 4N hydrochloric acid. A very small 
part is extracted by ether or amyl alcohol-gasoline from N/64 sodium 
hydroxide. The colors of archil, saffron, and cochineal also are easily 
extracted by amyl alcohol from slightly acid solutions but only in small 
amount by ether. 

The colors of leaves, egg yolk, fats and oils, carrots, and tomatoes, 
all similar or identical, are taken up by ether from neutral solutions and 
removed from this solvent by dilute alkali. 

Reactions in Aqueous Solution and with Sulphuric Acid. — The table 
by Loomis * on pages 822 and 823 gives the colors of a 0.1% solution of 
natural dyes as observed in a |-inch test-tube, the reactions of 10 cc. of the 
solution with 5 to 10 drops each of hydrochloric acid (sp.gr. i.i), of 10% 
sodium hydroxide solution, and of ammonia water (sp.gr. 0.95), the reac- 
tions of 5 cc. of the solution with 0.2 gram of zinc dust and 10 drops of 
concentrated hydrochloric acid; also the colors obtained by shaking 0.05 
gram of the dry color with 5 cc. of concentrated sulphuric acid and after 
dilution (cautiously with the first 20 cc.) until the change of color is merely 
in intensity. 



* Loc. cit., pp. 59-61. 



ARTIFICIAL FOOD COLORS. 821 

Specl/vl Tests for Vegetable Colors.— Archil, Cudbear, and 
Litmus, all derived from lichens, by the double dyeing method dye wool 
red in acid bath.* The colored fiber is turned blue, purple, or violet by 
treatment with ammonia. For other reactions on the fiber see tables, 
pages 819 and 835. 

Robin's Test for Archil in aqueous solution consists in shaking it with 
ether, which, if archil is present, is colored yellow. On treatment of the 
ether with ammonia, the yellow color is changed to blue, and, by adding 
acetic acid, goes over to a reddish violet. Other reactions of lichen colors 
are given on pages 820 and 822. 

Logwood, according to Robin, in aqueous solution colors ether yellow, 
and on treating the ether with ammonia the color becomes red or faintly 
violet. Potassium bichromate gives a violet coloration, mingled with 
greenish yellow. If cotton is first mordanted by boiling with aluminum 
acetate, it is dyed violet when boiled in a solution of logwood. Reactions 
of chrom mordanted cotton dyed with logwood are given on page 819 and 
of the solution of the dye on page 822. 

Turmeric is best extracted from a dry residue with alcohol, which it 
colors yellow. The color is transferred to a piece of filter-paper by soak- 
ing the paper in the alcoholic tincture, the paper is dried and dipped 
in a dilute solution of boric acid or borax slightly acidulated with hydro- 
chloric acid. On again drying the paper, it will be of a cherry-red color 
if turmeric is present, and when touched with a drop of dilute alkali will 
turn dark olive. For solubilities of curcumin, the coloring principle of 
turmeric, see page 872, and for reactions on the fiber see page 856. 

Caramel. — Care should be taken in testing for caramel not to subject 
the sample to long-continued heating, even on the water-bath. Indeed, 
caramel is sometimes developed spontaneously in saccharine food prod- 
ucts during their process of manufacture when heat is used, by the charring 
of the sugar. If solutions are to be concentrated or brought to dryness 
before testing for caramel, this should be done in a vacuum desiccator 
over sulphuric acid, or at a temperature not exceeding 70°. For detection 
of caramel in milk, vinegar, and liquors, special tests are given elsewhere. 

Fradiss Test.-\ — Extract the dried residue of the sample to be tested 
with warm, pure methyl alcohol, which, if caramel be present, is colored 
brown. Filter, and to the filtrate add amyl alcohol or chloroform. In 

*Tolman, Jour. Amer. Chem. Soc, 27, 1905, p. 213. 

fOestr. ungar. Zeits. Zuker Ind., 1899, 28, 229-231; Abs. Zeits. Unters. Nahr. 
Genussm., 2, 1899, p. 881. 



822 



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824 FOOD INSPECTION AND ANALYSIS. 

presence of caramel, a brown flocculent precipitate is formed, which slowly 
settles to the bottom of the tube. 

Amthor Test.* — Mix in a cylinder lo cc. of the solution, 30 to 50 cc. of 
paraldehyde, and sufficient absolute alcohol to make the liquids miscible. 
After the brown caramel precipitate has settled decant off the liquid, wash 
with absolute alcohol, dissolve in a few cc. of hot water, and filter. Note 
the intensity of the color of the solution, then pour into a freshly prepared 
solution of two parts of phenylhydrazine hydrochloride, 3 parts of sodium 
acetate and 20 parts of water. A considerable amount of caramel will 
give a precipitate in the cold. Heating hastens the separation and long 
standing is essential if the amount is small. 

Lasch^'s modification of this test is described on page 784. 

Indigo, both natural and synthetic, is insoluble in alcohol and in water 
and therefore suited only for solid foods. It has been used for coloring 
confectionery and facing tea. With concentrated sulphuric acid the 
dry material becomes yellowish changing slowly to blue-green. 

Sidphonated Indigo, also known as indigo carmine, indigo extract, 
indigotine, and indigo disulpho acid, being soluble in both alcohol and in 
water and allowed under federal ruling, is the basis of most blue food 
colors and also mixed with red and with yellow dyes of violet and green 
shades respectively. Its reactions in solution and on the fiber are given 
on pages 868 and 854, 

Cochineal. — This animal dyestuff is used in ketchups, cordials, con- 
fections, and other food products. 

Robin Test. — Acidulate the aqueous solution with hydrochloric acid, and 
shake out in a separatory funnel with amyl alcohol. Cochineal imparts to 
this solvent a yellowish color, the depth depending on the amount present. 
Wash the separated amyl alcohol with water till neutral, and divide into 
two portions. To one of these add a little water, and then drop by drop 
a solution of uranium acetate, shaking each time a drop is added. In 
presence of cochineal the water is colored a very characteristic emerald- 
green color. To the other portion add ammonia. If cochineal has been 
used, a violet coloration is produced. 

COAL-TAR COLORS. 

So many of the coal-tar dyes can be used in food products that it would 
be impossible to even name them all, especially in view of the fact that 

* Zeits. Anal. Chem., 24, 1885, p. 30. 



ARTIFICIAL FOOD COLORS. 825 

new colors are from time to time being added to the list. No attempt 
will be made in the present work to give the nature and composition of 
the dyes named, as such descriptions would lead beyond its scope. For 
detailed information along this line the reader is directed to the works 
of Schultz and Julius, Green, Mulliken, etc. 

Green's list compiled in 1903 includes 688 coal-tar colors but does not 
claim to be complete. Mulliken described 1475 ^Y^^ found on the American 
market in 1909. Although some natural dyes and possibly a few mixtures 
are included the total of these is more than offset by definite individuals 
of coal-tar origin which are not enumerated because obsolete or for other 
reasons not available or have been discovered since the date of publication. 

Various classifications of these colors are attempted, based on (r), their 
origin, as anilin dyes, naphthalin dyes, anthracene dyes, etc.; (2) their 
chemical composition, as nitro, nitroso, azo, diazo, azin, and other com- 
pounds; (3), their solubility in water and other solvents; and (4), their 
mode of application to the fiber, as basic dyes, acid dyes, direct cotton dyes, 
mordant dyes, etc. 

These dyes are sold in the form of powder, and are readily made 
into solutions for food colors in the case of the water-soluble varieties, 
and into pastes in the case of the insoluble forms. Most of the coal-tar 
colors employed in foods are naturally of the soluble variety, especially 
such as are found in jellies, jams, fruit products, canned foods, ketchups, 
beverages, and milk. Pastes made from insoluble dyes are adapted 
mainly for exterior coatings of hard substances such as candies. Colors 
in the dry form are to be looked for in such spices as cayenne, mustard, 
and mace, but a commoner method of coloring these spices high in oil 
is to mix with them a solution of the color in oil (usually cottonseed) . 
Oil solutions of coal-tar dyes are also employed for coloring butter and 
oleomargarine. 

The chief concern of the food analyst, as regards artificial color is 
its recognition in food products. Coal-tar dyes may usually be iden- 
tified as such, but it is not always possible to name the particular individ- 
ual dye or combination of dyes employed, even though the class to which 
they belong may be determined. One reason for this is that not infre- 
quently mixtures of two or more colors are employed. 

Coal-tar Colors Allowed under the Federal Law.* — The use of any 
dye, harmless or otherwise, to color food in a manner whereby damage 

* Food Inspection Decisions, Nos. 76, 77, 106, 117, 129, and 164. 



826 FOOD INSPECTION AND ANALYSIS. 

or inferiority is concealed is in violation of Sec. 7 of the Food and Drugs 
Act of June 30, 1906. The addition of all mineral or metallic dyes, and 
all coal-tar dyes, other than those specially provided for, is also prohibited. 
Pending further investigation the following coal-tar colors are permitted 
in foods, provided they are certified to be true to name and to be free from 
mineral and metallic poisons, harmful organic constituents, and contamina- 
tions due to improper or incomplete manufacture : * 

Red Shades. — 107. Amaranth [M.] [C.]. Synonyms: Fast red D [B.] 
Bordeaux S [A.], azoacidrubine 2B [D.\, fast red EB [B.]. 

56. Ponceau 3R [^4.] {B.[ [M.]. Synonyms: Ponceau 4R [A.], 
ciimidin red, cumidin ponceau. 

517. Erythrosin [B.] [M.] [B.S.S.]. Synonyms: Erythrosin D [C], 
erythrosin B [A.], pyrosin B [Mo.], iodeosin B, eosin bluish, eosin 

J [B.]. 

Orange Shade. — 85. Orange I. Synonyms: Alphanaphthol orange, 
naphthol orange [A..\ tropseolin 000 No. i, orange B [L.]. 

Yellow Shades. — 4. Naphthol yellow^ S {B.\. Synonyms: Naphthol 
yellow, acid yellow S, citronin A (Z,.). 

94. Tartrazin [B.] [/.] [H.]. Synonym: Hydrazin yellow [O.]. 

Green Shade. — 435. Light green SF yellowish [B.]. Synonyms: 
Acid green [By.] [M.] [T.M.] [O.], acid green extra cone. [C.]. 

Blue Shade. — 692. Indigo disulphoacid. Synonyms: Indigo car- 
mine, indigo extract, indigotine [B.], sulphonated indigo. 

None of these colors is patented, hence their manufacture is not likely 
to become a monopoly. They may be used in combinations, thus secur- 
ing any desired shade. For example, violet may be obtained by mixing 
indigo disulphoacid and one of the red colors, a blue-green by mixing 
indigo-disulphoacid with naphthol yellow S or light-green SF and 
so on. 

EXAMINATION OF COAL-TAR FOOD COLORS.— The testing of synthetic 
colors designed for foods differs from the task confronted in the dyeing 
industry in that the number of dyes is more limited and the presence of 
injurious substances, especially metallic by-products, is of paramount 
importance. A knowledge of the probable and possible dyes is naturally 
a great aid in examining samples; with this information the various analyti- 



* The numbers preceding the dyes are those given by Green; the letters in brackets 
represent the manufacturers who originated the names. 



ARTIFICIAL FOOD COLORS. 827 

cal schemes and tables covering the whole field can be used to best advan- 
tage. These same data are also of value in detecting colors in foods, and 
on the other hand, the tables of solubilities and reactions, as well as general 
methods, designed especially for the examination of foods for foreign 
colors, apply also to the food colors themselves. 

Analytical Schemes. — Witt,* the pioneer in the identification of dyes, 
devised a scheme employing the reactions and color tests with acids, 
alkalies, and other reagents, reduction with zinc dust and subsequent 
oxidation by exposure to air, as well as dyeing tests, and spectroscopic 
examination. As a means of learning whether or not a dye was a 
mixture, he devised the very useful test of dusting the powder over con- 
centrated sulphuric acid, noting the color as the individual particles dis- 
solved. 

Weingartner t revised Witt's scheme, adding new dyes and employing 
tannin solution to differentiate acid and basic colors. In testing for mixtures 
he sprinkled the powder over a filter paper moistened with water. 

Green J introduced chromic acid as an oxidizing agent, following 
reduction with zinc dust, but later, with his associates Yoeman and Jones, § 
rejected both reagents in favor of sodium hydrosulphite (" T blankite ") 
and potassium persulphates, both of which are colorless. 

Rota in his scheme (pages 827 to 832) departs quite radically from 
class reactions developed by Witt and others of his school. 

Of special value are the tables of Green || (based on Schultz and Julius), 
and Mulliken.^ The latter has the advantage of being more recent, more 
distinctly analytical, and broader in its application owing to the greater 
number of dyes included and the wider variety of tests (including spectro- 
scopic) employed. 

Rota's Analytical Scheme ** is based on the structure of the dyes 
as shown by their reactions with certain reagents. The colors are divided 
into two main groups, according to whether or not they are reducible by 
stannous chloride. These two groups are each further subdivided into 



* Zeits. anal. Chem., 26, 1887, p. 100. 

tibid., 27, 1888, p. 232. 

J Jour. Soc. Chem. Ind., 12, 1893, p. 3. 

§ Jour. Soc. Dyers, Colorists, 9, 1905, p. ^36. 

II A Systematic Survey of the Organic Coloring Matters, London, 1904. 

If Identification of Pure Organic Compounds, Vol. VI, New York, 19 17. 

** Chem. Ztg., 22, 1898, p. 437. 



828 



FOOD INSPECTION AND ANALYSIS. 



two classes, the reducible colors being classed according to whether the 
color remains unchanged, or is restored by treatment with ferric chloride, 
and the non-reducible colors according to their action with potassium 
hydroxide. 

The tests are carried out on a dilute aqueous or alcoholic solution 
of the coloring matter, the strength being about i in 10,000. Treat 
about 5 cc. of this solution with 4 or 5 drops of concentrated hydrochloric 
acid and about as much 10% stannous chloride solution, shake the mix- 
ture, and heat if necessary to boiling. With some colors the process of 
decolorization is a slow one, especially if the solution is too concentrated, 
and it is well to repeat the experiment, if in doubt, diluting the original 
sample still further with water. Tin in solution in concentrated hydro- 
chloric acid may be employed instead of stannous chloride, if desired. 

Here, as in all cases of color testing, it is well to make comparative 
tests with known colors. 

CLASSIFICATION OF ORGANIC COLORING MATTERS. 

[A portion of the aqueous or alcoholic solution is treated with HCl and SnClj.j 



Complete decolorization. Reducible coloring 
matters. Colorless solution is treated with 
Fe_,Cle, or shaken with exposure to air. 



The color changed no further than with HCl 
alone. Nonreducible colors. A part of 
original solution is mixed with 20% KOH 
and warmed. 



The liquid remains 
unchanged. Color- 
ing matters not re- 
oxidizable. 



Class I. 

Nitro, nitroso, and azo 
colors, including 
oxyazo and hydrazo 
colors. 

Picric acid, naphthol 
yellow, ponceau, 
Bordeaux, and 
Congo red. 



The original color re- 
stored. Reoxidiz- 
able coloring mat- 
ters. 



Class II. 

Indogenide and imido- 
quinone coloring 
matters, methylene 
blue, safranin, in- 
digo carmine. 



Decolorization, or a 
precipitate. Imido- 
carbo-quinone color- 
ing matters. 



Class III. 

Amido-derivatives of 
di and triphenyl 
methane, a u r a - 
m ins, acridins, 
quinolins, and 
color derivatives of 
thio benzenil. 

Fuchsin, rosaniUn, 
suramin. 



No preci p i t a t i o n. 
Li(juid becomes 
more colored. Oxy- 
carbo-quinone col- 
oring matters. 

Class IV. 

Nonamide diphenyl 
methane, oxv-ke- 
tone, and most of 
natural organic col- 
oring matters. 

Eosins, aurin, aliz 
arin. 



g c^ 



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ARTIFICIAL FOOD COLORS. 829 



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830 



FOOD INSPECTION AND ANALYSIS. 




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ARTIFICIAL FOOD COLORS. 



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832 



FOOD INSPECTION AND ANALYSIS. 



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ARTIFICIAL FOOD COLORS. 833 

Separation and Identification of Allowed Colors. — Price * devised 
a method for the identification of the seven colors allowed under Food 
Inspection Decision 76, 1907. The addition of tartrazin to the list neces- 
sitated a modification of the method. 

Price-Estes Method. '\ — The scheme is given on page 834. 

Price-Ingersoll Method.% — Ingersoll states with regard to the Price- 
Estes method that when small amounts of the dye are taken out of the 
original mixture on extraction with the ammonium sulphate reagent the 
separation is difficult or impossible, furthermore, that while some tartrazin, 
like naphthol yellow S, is soluble in that reagent, the larger part is not, 
following Price's directions. He accordingly proposed the following 
modification of the Price method: 

Rub from o.i to 0.2 gram of the dye sample, depending upon the amount 
of foreign salts in the mixture, with 25 cc. of saturated ammonium sulphate 
solution in a mortar and filter through a dry filter. If the filtrate comes 
through red, wash the color residue in the mortar and on the filter with 
successive 10 to 15 cc. portions of the ammonium sulphate solution until 
the washings are no longer colored red. The filtrate and washings contain 
the greater part of the amaranth together with some naphthol yellow S 
and also some tartrazin. Combine the filtrate and washings and shake 
with successive portions of acetic ether until the acetic ether is no longer 
colored yellow. The acetic ether removes that portion of the naphthol 
yellow S which was dissolved by the ammonium sulphate solution and may 
be discarded, since the greater part of this dye is recovered later in the 
scheme. Shake the ammonium sulphate solution containing amaranth 
and some tartrazin with acetone to remove these colors ; discard the ammo- 
nium sulphate solution, dilute the acetone portion with an equal volume 
of water, and drive off the acetone on a steam bath. Saturate with sodium 
chloride, add 10 cc. of alumina cream, agitate, warm, settle, filter, and wash 
with warm saturated sodium chloride solution until the washings are no 
longer colored yellow. To recover the amaranth, suspend the alumina 
cream precipitate in saturated ammonium sulphate solution and shake 
with acetone. 

The filtrate contains tartrazin and is to be discarded, or, when dealing 
with small amounts, if desired, can be saved and the tartrazin identified 
with the greater portion of this color separated further in the scheme. 

* U. S. Dept. of Agric, Bur. of Anim. Ind., Circ. 180, 191 1. 
t Jour. Ind. Eng. Chem., 8, 1916, p. 11 23. 
Jlbid., 9, 1917, p. 955. 



834 



FOOD INSPECTION AND ANALYSIS 



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ARTIFICIAL FOOD COLORS. 835 

Dissolve in water the portion of the original sample not dissolved by 
ammonium sulphate, acidify with acetic acid, and shake with successive 
portions of ethyl ether until the ether is no longer colored. The ether 
contains erythrosine, which it is very essential to remove completely from 
the other dyes before proceeding further. Wash the ether solution several 
times with water and finally extract the erythrosine from the ether with dilute 
ammonia solution. Remove the ammonia by evaporation on the steam 
bath and observe if this solution, when very dilute, has any fluorescence 
which might indicate the pressure of prohibited colors having similar reac- 
tions. Remove the ether from the acetic acid aqueous solution by warming 
on a steam bath, saturate with sodium chloride at steam bath temperature, 
and add sodium chloride in excess; cool and filter through a dry filter. 
Wash with saturated sodium chloride solution until the washings are color- 
less. When a bulky precipitate is obtained here, which is difficult to wash, 
it may be time-saving to redissolve the precipitate and excess salt in water 
and repeat the salting and washing process, adding the filtrate and washings 
to those of the first saturation. The combined filtrate and washings con- 
tain light green SF yellowish, naphthol yellow S, tartrazin, traces of orange 
I, and possibly amaranth, since the latter dye may not be entirely removed 
by the first extraction of the dry sample with the ammonium sulphate 
reagent. 

To separate the naphthol yellow S, extract with successive portions 
of acetone until the acetone fails to remove any more color. Combine 
the acetone extracts and wash with several portions of saturated sodium 
chloride solution to remove traces of tartrazin and light green SF yellowish 
from the acetone. Add to the acetone solution an equal volume of water 
and drive off acetone on the steam bath. Acidify the water solution and 
shake with amyl alcohol to remove traces of orange I that may be present; 
discard this amyl alcohol solution. Drive off all amyl alcohol mechanically 
held in the aqueous solution by warming on the steam bath and test this 
solution for naphthol yellow S. 

To separate the light green SF yellowish from the tartrazin, remove 
the acetone from the aqueous salt solution by heating on the steam bath, 
and add fuller's earth in the proportion of 0.5 gram to each 10 cc. of warm 
dye solution. After mixing well and heating, allow to settle; then filter 
and wash with water. The light green SF yellowish remains on the filter 
and can be dissolved in strong, hot acetic acid and further identified. If 
tartrazin was present in the original mixture, the filtrate from the precipita- 
tion of the light green SF yellowish will be yellow or golden yellow, not 



836 FOOD INSPECTION AND ANALYSIS. 

decolorized by hydrochloric acid. Imperfect removal of naphthol yellow 
S, previously, would result in a yellow filtrate here which could be decolor- 
ized by hydrochloric acid. The tartrazin can be further isolated from a 
possible trace of amaranth by adding lo cc. of alumina cream to each loo cc. 
of solution, mixing, warming, and filtering, when the tartrazin will be 
found in the sodium chloride filtrate. To isolate from the salt, evaporate 
and redissolve in alcohol. 

Dissolve the precipitate containing orange I, ponceau 3R and indigo 
disulfo acid, together with excess sodium chloride on the filter paper, in 
water and extract with three successive portions of acetic ether. Orange I 
is taken up by acetic ether. Combine the acetic ether extracts and wash 
with saturated sodium chloride solution, until no more color is removed. 
Extract the acetic ether solution with water to obtain the Orange I in an 
aqueous solution and free from acetic ether by warming on the steam 
bath. 

Warm the water solution containing ponceau 3R and indigo disulfo 
acid, from which the greater part of the Orange I has been removed on 
the steam bath until free from acetic ether, cool, add 10 grams of granu- 
lated calcium chloride, allow to stand fifteen minutes, and then add 15 cc. 
of a freshly prepared stannous chloride solution containing the equivalent 
of 3% metallic tin and 12% of hydrochloric acid (sp.gr. 1.19). Mix well 
and allow to stand until the solution shows no blue color. If ponceau 3R 
is present, it will be precipitated. Filter immediately, wash the precipitate 
twice with 25% calcium chloride solution to remove all the reduced indigo 
disulfo acid, dissolve the remaining residue in dilute ammonia solution 
and test for ponceau 3R. 

To the filtrate, which should be practically colorless, add 3% hydrogen 
peroxide solution. A deep blue coloration indicates the presence of indigo 
disulfo acid. 

Quantitative Separation of Acid Coal-tar Colors. — Mathewson 
Method."^ — This process, like the preceding, is for the colors themselves, 
but may be adapted for the detection of the colors in food products after 
separation by means of solvents or less satisfactorily by dyeing. Mathew- 
son's table is given on pages 837 and 838. 

In applying the data given in the table proceed essentially as follows: 
Treat the solution containing 0.2 to 0.4 gram of color (depending on the 
nature of the dyes) with sufficient water and hydrochloric acid to bring 

* U. S. Dept.of Agric. Bur. of Chem., Circ. 89. 



ARTIFICIAL FOOD COLORS. 



837 



its volume to about 50 cc. and its acid concentration to that point for 
which the difference in percentage of color extracted for the two dyes is 
near its maximum. Shake the solution with the immiscible solvent, 
passing it in succession through three or four separatory funnels each 
containing 50 cc. of the latter. Wash the portions of the solvent with 50 
cc. of hydrochloric acid of the same normality as the solution, passing it 



MATHEWSON'S TABLE SHOWING PERCENTAGE OF COLOR IN THE WATER 
SOLUTION AFTER SHAKING WITH AN EQUAL VOLUME OF IMMISCIBLE 
SOLVENT. 

solvent: amyl alcohol. 



Colors. 



Naphthol Yellow S No. 4 . . 

Orange I No. 85 

Ponceau 3 R No. 56 

Amaranth No. 107 ....... 

Light Green S F No. 435 . . , 

Erythrosin No. 517 

Indigo Carmin No. 692 . . . . 

Fast Yellow No. 8 

Crocein Orange G No. 13 . . 

Orange G No. 14 

Ponceau 2 R No. 55 

Crystal Ponceau No. 64 . . . 

Fast Red B No. 65 

Resorcin Yellow No. 84 . . . 

Orange II No. 86 

Brilliant Yellow S No. 89 . . 

Tartrazin No. 94 

Metanil Yellow No. 95 ... . 

Fast Red A No. 102 

Fast Red C No. 103 

Fast Red E No. 105 

New Coccin No. 106 

Scarlet 6 R No. 108 

Resorcin Brown No. 137 . . . 
Cotton Scarlet 3 B No. 146. 

Congo Red No. 240 * 

Azo Blue No. 287 t 

Chrysophenin No. 329 

Guinea Green B No. 433. . . 
Acid Magenta No. 462 ... . 



Normality of Hydrochloric Acid in Water Layer before Shaking 



2 


I 


1 


1 
4 


1 
8 


^ 



Percentage of Color in Water Solution after Shaking. 



S 
90 



34 
36 



41 



75 



IS 
95 



SI 



IS 



3 

52 
97 



61 



73 
47 



95 



93 



7 
82 

99 



96 



14 



II 
0-5 



93 
99 



99 



58 

8 

16 

5 



90 



4 
17 
75 



32 



17 

I 

43 



27 



64 



39 

62 

II 

2 



20 
10 



25 



43 

4 

78 



17 
3 



* Color acid nearly insoluble in both layers. 

t Similar to Congo Red but color acid i.iore soluble in alcohol. 



838 



FOOD INSPECTION AND ANALYSIS. 



I 



MATHEWSON'S TABLE SHOWING PERCENTAGE OF COLOR IN THE WATER 
SOLUTION AFTER SHAKING WITH AN EQUAL VOLUME OF IMMISCIBLE 

SOLVENT— {Continued). 

solvent: dichlorhydrin. 



Colors. 



Normality of Hydrochloric Acid in Water Layer before 
i_ Shaking. 



Percentage of Color in Water Solution after Shaking. 



Naphthol Yellow S No. 4 . 

Ponceau 3 R No. 56 

Orange I No. 85 

Amaranth No. 107 

Light Green S F No. 435 . 
Indigo Carmin No. 692. . . 
Acid Magenta No. 462 .. , 



15 
37 
4 
95 
15 
91 



17 



Naphthol Yellow S No. 4 . 
Ponceau 3 R No. 56 . . . . 



solvent: amyl acetate. 



95 



33 
96 



97 



Naphthol Yellow S No. 4 . 
Orange I No. 86 



solvent: ether. 



94 
97 



97 
97 



successively through the separatory funnels in the same order as was 
the original solution, and repeat this operation with one or two fresh 
amounts of the hydrochloric acid. The dye relatively more soluble in 
water is determined in the combined washings and extracted solution. 
Remove the second dye from the solvent by shaking with water, very 
dilute caustic soda, or, more quickly, with dilute caustic soda after the 
addition of some gasoline, or similar substance in which the color is 
insoluble. 

The table given above shows the percentage of the color in the water 
solution after shaking with an equal volume of the immiscible solvent. 

Assuming the distribution ratios to remain constant, this procedure 
using four funnels and making three washings gives for a pair of colors 
whose " distribution numbers " (as the percentage numbers given in the 



ARTIFICIAL FOOD COLORS. 839. 

table may be called) are 80 and 20, respectively, a separation of 98.30 
per cent for each color. With distribution numb^^rs 90 and 10 four funnels 
and three washings give a calculated separation of 99.73%, and the same 
is obtained with distribution numbers 81.8 and 5.3 if the solvent in which 
the dyes are relatively more soluble be taken in portions one-half the 
volume of those of the other liquid. If the second, third, and fourth 
funnels be given a fifth washing, the third and fourth funnels a sixth, 
and the last funnel a seventh washing, the calculated loss for the color 
more soluble in the solvent layer is 0.76%, while the percentage of the 
other dye removed is relatively much increased (to 99.99%). In most 
mixtures the progress of the separation is always apparent. 

In practice, because of incomplete extraction and separation, and 
especially on account of uncertainty due to small amounts of subsidiary 
dyes always present, it is necessary to increase the number of successive 
extractions. The formation of esters of the color acids is a possible 
source of difficulty, but is not believed to take place. With amyl alcohol 
as solvent it is usually desirable to make the original solution more strongly 
acid than is indicated by the distribution data and use relatively more 
portions of the washing liquid. 

Of the permitted colors, Naphthol Yellow S is best separated from 
Orange I by washing the amyl alcohol solution of the color acids with 
strong salt solution, care being taken that not too much color is present. 
With a solution containing 20 grams of salt and 0.04 gram Naphthol 
Yellow S per 100 cc. and shaken with an equal volume amyl alcohol, 97% 
of the color is retained by the water. With a similar solution contain- 
ing 0.07 gram Orange I, the water layer contains 1.5% of the total color. 
With higher concentrations some color may be salted out in solid form, 
but this does not interfere if the amount is small. Erythrosin being 
quantitatively removed from slightly acid solutions by amyl acetate, ether, 
or amyl alcohol, its separation from sulphonated colors presents no 
difficulty. 

Analysis of Food Colors. — Seeker and his co-workers have devised 
methods for the analysis of the seven coal-tar colors allowed by federal 
decision in the United States. The methods are for the determination of 
the ultimate constituents and for impurities, including arsenic and other 
heavy metals. The reader is referred to Hesse's report * for details of these 
processes. 

* Loc. cit., pp. 210-226. 



,840 FOOD INSPECTION AND ANALYSIS. 

Loomis * has prepared a table giving the solubiHty of food colors in 
various solvents, and another table showing the relative amounts extracted 
from neutral, alkaline, and acid solutions, shaking with amyl alcohol, 
ethyl acetate and acetone, the aqueous solution in the latter case being 
saturated with salt. 

Spectroscopic Examination. — The absorption spectra of dyes, both of 
coal-tar and vegetable origin, in various solvents, have been described by 
Vogel t and by Formanek | on the Continent, by Sorby § in England, 
and by Mulliken || in the United States. These data, although specially 
designed for the dye chemist, are none the less valuable for the food analyst. 
Unfortunately, few chemists are equipped with suitable spectroscopic 
apparatus or are acquainted with the details of manipulation. 

Detection of Coal-tar Colors in Foods.— The examination of 
foods for foreign colors involves usually at least two distinct steps: First 
the extraction of the dye from the product, and second the identification 
of the dye thus removed; where more than one color is present a third 
step or series of steps is necessary to separate these colors previous to 
identification. 

Extraction of Colors from Foods. — There are various methods for 
the separation of coloring matters from food products, and these may be 
divided into three general classes: First, dyeing silk or wool with the 
color by boiling the fiber in a solution of the sample to be examined; second, 
extracting the color from a solution of the sample by the use of an immiscible 
solvent; and third, extracting the color from the dried residue of the sample 
by means of a suitable solvent. Of these the method of dyeing v/ool lends 
itself most readily to the analyst's use, by reason of its simplicity, and from 
the fact that the coal-tar dyes adapted for food colors, with few exceptions 
(i.e., auramin), being substantive dyes are readily taken up by wool, 
whereas the natural colors of foods are left in the solution. Some vegetable 
and animal dyes, such as lichen colors and cochineal, also dye wool, but 
these are readily distinguished from coal-tar colors by special tests. 

The Separation of Colors is best carried out by fractioning between 



* Loc. cit., pp. 8-21. 

t Praktische Spektralanalyse iridischer Stoffe, 1889. 

X Spektralanalytischer Nachweis kiinstlicher organischen Farbstoffe, 1900; Qualita- 
tive Spektralanalyse anorganischer und organischer Korper 1905; (with Grandmougin) 
Untersuchung und Nachweis organischer Farbstoffe auf spektroscopischem Wege. 

§ Proc. Royal Soc, 92, p. 1867. 

1 1 Loc. cit. 



ARTIFICIAL FOOD COLORS. 841 

aqueous solutions and immiscible solvents according to Mathewson's 
method, page 859. 

Identification of Colors. — Three types of methods are mostly used: 
First, spot tests, that is the application of reagents directly to the dyed fiber 
or dry color (pages 854-858) ; second, reactions in the solution of the color 
(pages 86S-875); and third spectroscopic examination. Most analysts are 
limited to the first two; those equipped with spectroscopic apparatus are 
referred to the work named on page 840. 

Basic and Acid Dyes. — The soluble coal-tar dyes are either basic 
or acid. Basic dyes are precipitated from their aqueous solution by 
tannin. Acid dyes are not so precipitated. Theoretically, all the basic 
colors are taken up by wool from a faintly alkaline or neutral bath, while 
the acid colors are left in solution. Thus if a dilute solution of the color 
be made faintly alkaline with ammonia and boiled with the wool, only 
basic colors will be taken up. If both acid and basic dyes are present 
in the same solution, the basic color should first be exhausted by the 
use of fresh pieces of wool in the ammoniacal solution, till they no longer 
take out color, after which the solution should be made slightly acid 
with hydrochloric acid and again boiled with wool, which under these 
conditions takes out any acid colors. Comparatively few basic colors 
are employed in foods. Basic colors can be removed from the fiber by 
boiling with 5% acetic acid. Acid colors are removed therefrom by 
boiling with z^^^q ammonia. Having dissolved the dye from the fiber 
by the appropriate solvent as above, the decolorized fiber may be removed, 
and the solution evaporated to dryness on the water-bath. The residue 
consists chiefly of the dyestuffs, and may be put through various reactions 
for identification. 

Methods of Dyeing Wool from Food Products. — The wool employed 
should be white worsted, or strips of white cloth, such as nun's veiling 
or albatross cloth. Care should be taken that the color is pure white 
and not the more common cream white. The woolen material should 
be freed from grease by boiling first in 0.1% sodium hydroxide solution and 
finally in water. Strips of the woolen cloth, or pieces of the worsted thus 
cleansed, are boiled in diluted unfiltered solutions of jams, jellies, ketchup, 
and other solid or semi-solid preparations, or in undiluted fruit juices, 
carbonated beverages, and of wines, the liquid, previous to the boiling 
being slightly acidified as described below. 

Arata * was the first to employ dyeing tests in an acid bath in food 

* Zeits. anal. Chem., 28, 1889, p. 639. 



842 FOOD. INSPECTION AND ANALYSIS. 

examination, but limited his observations to wines. Winton * later found 
that the method was well adapted to the detection of coal-tar colors in various 
foods. The method consists in boiling the wool in a dilute solution of the 
food material to which potassium bisulphate has been added, using lo cc. 
of a 10% solution of the bisulphate to loo cc. of the solution to be tested. 
If the color solution is neutral, the wool may first be boiled in this before 
acidifying, to separate out any basic dyes. The dyed wool, after removal 
from the solution, is boiled first in water, and afterwards preferably in 
an alkali-free soap solution. It is then washed and dried. The dried 
fiber may then be subjected to the various reactions given in the table, 
pages 854-858, for recognition of the dye. This method of identifying 
colors by means of reactions on the dyed fiber is one of the most con- 
venient — in fact Arata's test, supplemented by reactions on the fiber, 
suffices in many cases of suspected coloring. 

Some of the vegetable dyes (including lichen colors), also cochineal, dye 
wool directly, and these may be identified by special reactions. Other 
vegetable colors, and the natural colors of fruits nearly always give a 
slight dull coloration or stain to the wool, but this is not, as a rule, to be 
mistaken for the vivid hues of the coal-tar dyes. Moreover, most of the 
vegetable colors on the fiber turn green when treated with ammonia. Care 
should be taken to thoroughly wash the wool after the dyeing, so that 
colored particles simply held thereon mechanically may be removed. 

Sostegni and Carpentieri | recommend a method of double dyeing, 
applicable when acid dyes are employed. The wool is boiled in a solution of 
the food sample acidulated with hydrochloric acid, after which the fiber 
is removed and boiled, first in very dilute hydrochloric acid solution, and 
then in water, till free from acid. The color is next dissolved from the fiber 
by boiling the latter in a weak ammoniacal solution, some of the colors 
being more readily dissolved than others. The fiber is then removed from 
the solution, the latter is acidified with hydrochloric acid, and the color 
fixed on a fresh piece of wool by boiling therein. Tfie second dyeing fixes 
coal-tar and lichen colors on the fiber, but fruit colors and most others of 
vegetable origin remain in solution after this treatment. Any color left 
on the first fiber, after treatment with ammonia, is probably due to the 
natural vegetable color of the sample, and is usually no more than a dull 
stain. 



* Jour. Amer. Chem. Soc, 22, iqoo, p. 582. 
t Zeits. anal. Chem., 35, 1896, p. 397. 



ARTIFICIAL FOOD COLORS. 843 

Extraction of Colors from their Solution by Amyl Alcohol. — Methods 
based on this principle have for years been used in examining wines in the 
municipal laboratory at Paris* and were found by Wintonf to be adapted 
for various foods. Sangle-Ferriere uses the following method: 50 cc. of 
the wine or solution to be tested for color are rendered slightly alkaline by 
ammonia, and cautiously shaken with about 15 cc. of amyl alcohol. If 
acid dyes are present, they will be dissolved, and will impart to the amyl 
alcohol a distinct color. | Basic dyes also are dissolved, but when they 
are present the amyl alcohol solution is colorless. Remove the amyl 
alcohol by means of a separatory funnel, wash with water, and finally, 
if the alcohol is colored, dilute with about an equal volume of distilled 
water and evaporate on the water-bath with a piece of white wool. The 
wool should be kept in the solution till the odor of the amyl alcohol has 
disappeared, and, if not then colored, for a short time longer, as with 
some colors the wool will dye more readily in the aqueous solution than 
in the amyl alcohol. Remove the wool, and evaporate the solution to 
dryness. Test for color in the dried residue, and on the fiber also. 

Archil and other lichen colors, like the acid colors, is extracted by 
the amyl alcohol under the above conditions, the color being a light violet. 

If the amyl alcohol extract after separation, washing, and filtering 
is colorless, acidify with acetic acid; if a basic color is present, it will 
be indicated by a coloration at this stage; if there is no coloration on 
the addition of acetic acid, no basic color is present excepting fuchsin, 
which is separately tested for. In case a basic dye is indicated, add dis- 
tilled water and evaporate with wool as before. Test the dried residue 
with pure concentrated sulphuric acid. 

Fuchsin is mdicated by a yellow-brown color with sulphuric acid, 
which by dilution with water becomes rose; safranin, by a green color 
becoming first blue, then red, when diluted with water, and magdala 
red by a dark blue color, turning red on the addition of water. 

Many coal-tar colors are extracted by amyl alcohol in acid solution, 
but some fruit colors as well as cochineal are also dissolved under these 
conditions. The coal-tar dyes thus dissolved will, however, dye wool and 
the fruit colors will not. The test for cochineal in the amyl alcohol solution 



* Girard, Analyse des Matieres Alimentaires, pp. 183, 681. 
t Loc. cit. 

% Acid fuchsin forms an exception to this rule by dissolving colorless like basic dyes. 
Special tests are given on p. 845. 



844 FOOD INSPECTION AND ANALYSIS, 

is described on page 824. Fruit colors are not extracted from acid or alka- 
line solution by ether, nor from alkaline solution by amyl alcohol. 

Extraction of Colors from their Solution by Acetic Ether. — Basic 
colors are extracted readily, according to Robin, by making the solution 
to be tested alkaline with sodium hydroxide, and shaking with acetic 
ether. The solvent is removed, washed, and evaporated with wool (on . 
which the tests are to be made), or the evaporation is carried to dryness 
and the tests made on the residue. 

Separation of Acid and Basic Colors with Ether.* — Rota's Method.— 
To 100 cc. of the aqueous solution containing the color add i cc. of 20% 
potassium hydroxide and shake in a separatory funnel with several portions 
of ether. Basic dyes are dissolved by the ether, leaving behind as a rule 
the acid colors.f Wash the ether extract with faintly alkaline water, and 
shake out with 5% acetic acid. Some colors remain in the ether, others 
are dissolved in the acid. Separate the two solvents, and evaporate each 
to dryness on the water-bath. 

The acid colors left in the slightly alkaline, aqueous solution after 
removal of the basic colors by ether as above, may, if desired, be separated 
into several groups by successive extraction, as follows: first slightly 
acidulate with acetic acid and extract with ether, then acidify with hydro- 
chloric acid and again extract, and finally examine the residual solution 
for colors that are insoluble in ether. Thus erythrosin and eosin are 
soluble in ether when shaken with their aqueous solution made acid with 
hydrochloric acid, while acid fuchsin is insoluble. 

Separation of Colors from Dried Food Residues by Solvents. — This 
method is rarely employed, excepting in the case of colors insoluble in 
water, but soluble in ether or alcohol. The dried pulp' of canned vege- 
tables, ketchups, etc., may be acidified with hydrochloric acid, and the 
color extracted therefrom directly with alcohol. In this case, however, 
there is no obvious advantage over the previous methods of dyeing the 
fiber directly in the acid solution of the sample. 

Robin's Test for Acid Colors. — Add to the liquid to be tested an excess 
of calcined magnesia, and a little 20% mercuric acetate solution, boil, and 
filter. If the filtrate is colored, or if by the addition of acetic acid to the 
colorless filtrate a color is developed, a coal-tar dye is indicated. 



* Analyst, 24, p. 45. 

t A few acid dyes are exceptional in being soluble in ether with alkali, as for example, 
qui noli n yellow and the sudans. 



ARTIFICIAL FOOD COLORS. 845 

Girard's Test for Acid Fuchsin.* — Acid 2 cc. of 5% potassium 
hydroxide to 10 cc. of the wine or other solution to be tested, or enough 
of the alkah to neutralize the acid. Then add 4 cc. of 10% acetate of 
mercury and filter. The filtrate should be alkaline and colorless. If 
the solution remains uncolored after acidifying with dilute sulphuric 
acid, no acid fuchsin is present. If, however, there is produced a red 
to violet coloration, and no other coal-tar colors have been found by the 
amyl alcohol extraction, the presence of acid fuchsin is shown. 

Bellier's Test for Acid Fuchsin. — Presence of acid fuchsin is indicated 
by adding to 20 cc. of wine or other solution to be tested about 4 grams 
of freshly precipitated yellow oxide of mercury, boiling and filtering. 
The filtrate, if acid fuchsin is present, i? colored red, tinged with violet. 

According to Blarez, all red coal-tar colors, with the exception of 
acid fuchsin, and all red vegetable colors are completely decolorized by 
acidulating their aqueous solution with tartaric acid, and digesting with 
lead peroxide.! 

Loomis' Scheme for Preliminary Identification of Colors in Foods.| — 
This scheme covers certain coal-tar, animal, and vegetable dyes commonly 
used in foods. The strength of the aqueous solution should be approxi- 
mately 0.01% for coal-tar colors and 0.1% for animal and vegetable 
(" natural ") colors. 

The following reagents are required: 

Weingartner^s Tannin Reagent. — A solution of 10 grams each of tannic 
acid and sodium acetate in 100 cc. of water. 

Hydrochloric Acid. — Equal volumes of concentrated acid and water. 

Sodium Hydroxide Solution. — Ten grams in 100 cc. of water. 

Ammonia Water. — Approximately 10% NH3. 

Lead Siihacelate Solution. — See p. 610. 

Normal Lead Acetate Solution. — Ten grams in 100 cc. of water. 

Reactions in aqueous or alcoholic solution are carried out with 10 cc. 
of color solution and 5 to 10 drops of reagent; unless otherwise noted, each 
test is made on a part of the original solution. To determine whether a 
large or small amount is extracted by an immiscible solvent from an 
aqueous solution, separate the former, filter, evaporate (with addition of 
water if necessary), take up in water, add a little acid or alkali to correspond 



* Analyse des Substances Alimentaires, p. 185. 

t Allen, Commercial Org. Analysis, 4 Ed., Vol. V, p. 250. 

I Loc. cit., pp. 62-69. 



846 



FOOD INSPECTION AND ANALYSIS. 



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ARTIFICIAL FOOD COLORS. 



847 



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848 



FOOD INSPECTION AND ANALYSIS. 






in 

o 
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w 

o 

2 



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Iv, 1^ K, 



s a 



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96 



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ij & .ii 






C oi OJ rn SP <" + 









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p 3 ti "o i 



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T1 ^ ^-^ Lj 



o -o o 



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ARTIFICIAL FOOD COLORS. 



849 



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H 



aj 



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g 3 
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a 



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6 i 

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lO 








1^ 






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00 


g 


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a:^ 



ex 

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ni 2 



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850 



FOOD INSPECTION AND ANALYSIS. 



^^ o 






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tq ftj 



I 

P^ 
O 

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HH O 





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c/} 


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a 


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3 

1> 


cr 
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s 
s 

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O 
H 

O 


O 

(J 
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12 

'35 

c3 




«H 


in 

O 




T3 


« 






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hi 






^ 






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2 


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+ 1 



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^ ■■;; •■;: 



^ ^ 



tq 






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"n '-' 



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« c 



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tn 


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> >-i y tfl 

>-.'■£ *-■ -E 

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=^ .£ >- "o -y 

— — O 1) c 

in > o o <-j 



•- ^ t: o 



C 33 O 



.22 .n 






pi; 



(3 O *i> 1^ 






3 pq ^ ■" ^ ^ -S 
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d o «' "=^' 



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fq 



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ARTIFICIAL FOOD COLORS. 



851 



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K) 



a o^ fc. 



O fc. 



0^ •:« O 



^fi: 



ffl 



Ei O 

u o 

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o 4-; c 

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a " u, 



o a. 



M 5 



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ui 2 *-i 



^ ^ .00 -^ — "i 



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c y T3 o 



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cq 



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cq 



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^^ ?; ^ -^ ^ 



2 o 



o Td 



o £ ^ 



*j _2J > <-J .h <a 



^ -7- w .a 
o S '-' '-' 



a> o 



ID 

3 
CM 



o Q Q ^ 



o c a D 

'" "i n ii 
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5 2 



o ^ 



^ 51 rt S 



< < d "o 



^ go 

a "o 

I " 



•c 2 



t- ?r 



-sen 






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BQ 



K) 



3 d ^ i 

rt .2 c! .ti 



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& i 



o o 

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1; .3 



Si OJ <u 



f^ '=1 ^ 



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aj -- 

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[II 



852 



FOOD INSPECTION AND ANALYSIS. 



rO On M S 



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g S 



cq 



w 




p^ 




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O 

u 


% 




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Q 


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s 


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c^^ 



HH e 



2 .§ . fe 



o 



^ z 



H X ^^ ^ 



CJ O 



ri ^ 



,„ P COO 



^ 


o 


o 


vS 


u 


c 


& 


G 


J_, 




c 




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<; 


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o 


H 


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l-H 


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2 








ai 




CO 







"go 



g o . 

o -o 



.£ x) "^ 
u P o 



to 



O 



_> 
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C/3 








O 


ffi 




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cu 




K 
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T3 




Q 


OJ 
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c 




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O Q 



ARTIFICIAL FOOD COLORS. 853 

with the aqueous layer, and compare with the latter. Dyeing tests may be 
made on the solution thus obtained. When the solution is decolorized by 
acid or alkali during shaking with an immiscible solvent, separate both 
layers and neutralize both in order to find the relative portions of color 
in the two. 

Direct Identification of Colors. — In identifying the colors commonly 
used in food, it is frequently possible to ascertain the color or group of 
colors present by making direct tests with various reagents, either on the 
dyed fiber or on the dry coloring matter, or in a solution containing it. 

Many tables for this purpose are prepared, but they are never com- 
plete by reason of the many new dyestuffs constantly introduced. Such 
tables are to be found in the works of Allen, Schultz and Julius, and 
Mulliken. While it is true that the limitation of the dyes suitable for pur- 
poses of food coloring imposes a somewhat lighter task on the food analyst 
than that on the chemist who has to deal with all varieties of commercial 
colors, yet it is obviously impossible to make a complete list covering even 
the restricted field of food colors. Doubtless there are colors long well 
known that would serve admirably for this purpose, but have never yet 
been tried. 

Reactions of Dry Colors or Dyed Fibers.— For the purposes of the 
food analyst the table of Mathewson* (pages 854 to 858) is well adapted as 
it includes colors which actually have been found in foods, being the same 
colors as are also included in the table on pages 868 to 875. 

The analyst should be provided, for standards, with as complete a 
collection of known purity dyestuffs as possible covering the colors he is 
likely to meet with in foods, and should make comparative tests, if the 
slightest doubt exists. If the unknown color is apparently not found in the 
table, and the more exhaustive tables are unavailable, it is still possible 
to locate the dye, by making similar tests on other standard colors sug- 
gested by the behavior of the unknown color, and carefully comparing 
them. 

Most difficulty is encountered when the coloring matters are mixtures 
instead of simple dyes. In this case it is recommended to resort to syste- 
matic separation by immiscible solvents as elaborated by Mathewson 
(page 859). 



* Separation and Identification of Food-coloring Substances, U. S. Dept. of Agric, Bui. 
5, pp. 37-45- 



854 



FOOD INSPECTION AND ANALYSIS. 



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•d •d 


0) 
Ih 


CTJ 

•d 


x: •d 


•d 


OJ 

•0 




3 


0! 

x: 


Ih 


0! 
X 


OJ 

x: 




C.2 


0) 

■d 


'oj 'a3 


"3 "3 


s 3; -° 


3 


(U Oi 

Pi Pi 


3 


_>^ 


UJ CJ 

'$ Pi 


>. 


_>> 


" X 


c 

CJ 


CJ 

OJ 


DO 
3 





y 


" "J b 

OJ CL i? 




§2 


ca 

OJ 


>H >< >H >H >H >H 3 
P 


S 




S 







x; 

M 
CO 


X 
bO 

w 


1^ +^ 'B Ih 

^.y QO 


3 


2 



:n -n -n ■ ■ P 

4-> +J -M 

13 3 J 




X 


•z 






































"o 








.M 

































Q 


T3 







<U 0) 
3 3 

c c 

Si 2 


^ G >. 

^ 2 & 

3 


•d 
(2 


& & fe 
000 


OJ 

3 

S 




Is 

1 Ih 

0) ta 
bo 


•d 

OJ 

Pi 




■3 


c 

OJ 
0) 

ho-d -d 

i OJ CJ 

tpiPi 




0! 

3 

OJ 
_3 




"3 
>. 

i 
DO 
3 


■d 
2 

3 


OJ 


•d 

OJ 


OJ 4-> 
Ih 
■IJ 3 Tl 







> 















a! 
u 








"3 


5 


Oj 
Ih 



> 






> 




"o 








s 









































































J 

C . 
2 CI 

C 








(U 






•d 


OJ 

a 
3 




C -P 















3 




T) 


c 


mW 


_oo_o_ooo_o-^ 
'oj'S'aj'aj'aj'aj'a; ^ 


> 


"3 "3 


Ih 







4J 

"3 
> 




2 c c 

XI OJ CJ 

to6 


3 


"3 
>. "d 

CJ ^ 

DO K 
3 


OJ 

2 

bO 

CJ 

3 


•d 

OJ 

Pi 


CJ 

> m .2 
> 










R 






Ih ^< 


> 


> »J f^ 






"3 





2 




S 
















m m 












>H 













C 


J 










































N 


n 10 


a 


M N 


00 


00 Oi 


0\ « 


Oi vO 


t- 


"di 


00 10 >* 


00 


^ 


^ 


00 





PO ro 




. c 


vO 


fO w 


ro fO 


Oi ■* 





* 


00 


e> 


a 





o> 


a 


CO 


M 


N 




M 


0\ 00 10 




<u 


•^ 


Tt ^ 


■<t ■* 


■J^ Tj- 




* 


* 


(0 


n M 


tH 




CO <3 vO 


M 


* 




fO 




:^ * 




l^ 


* 




•jt 


* 


* 


* 


* 




* 






* 




* 








* 




^ 






^ 


^ 








* 










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* 







* 
















* 


















* 




^ 







































ARTIFICIAL FOOD COLORS. 



855 



E p. 
< 



0) 



0) O lU D 

00 60 M 6(1 






^ o 2; > 
< 



■g o u o o ij o 

■v; <u K <u <u o <u 
9 r-; Ti Ti t; rn "r: 



5 S ^ J3 ^ ^ 
J3 J3 O " O O 

o o '^ T3 '^ '^ 



•d 60 bo ij aj a) ^ 

J'ClC'£6060'r<60 

BOO o "^j3 &.£3 
COJCD-OUOOO 

O .ti .ti Pi Z 2 " z 



£3 



S^S 



c 8 -g ^ 
& -^ o .2 
2=3 2: > 



c S; oj o p 



^ t: ^ 



3 -p 3 W w Q 
P Q Q 



^ -2 






C & 



"d ^ °i ii ''^ •« <u 

<" " O O >, <U M 
^^ i^ > > -M ^^ S 



0) ■*-> 

60 M _^ 

S ° "^ 

X > -a 

" CI - 

a; > -d 

J pa 



■^ c g 


j:: 


>, ol U 








■MOV. 




60 =3 ^ 


+J 


■^ 3 




W Q 





0) 




n1 


< 










c 






n 


c 


jn 


o 


J_, 


u 


3 



.■S Di ii . - .- 



.2 « 



M ^ J3 

« -2 S 



3-«3 



60 ^ 60 
4i _■ C p C 



O > 



2 o O 



60 3 J!i 

>d S .2 
•S m r 



'-a -o .^ 
(5 iS g 



•s< 


0) 


0) 

_3 
7i 


'n 


60 


0) 
60 




•a 




0) 
60 


r.S. 


c 


_o 


C 


C 


^ 


^J 


c 


o 


>. 


o 


o 


J3 




•s 


o 


o 


di^ 


V 


^j 










o 

> 


> 


a> 


Sg 




60 


_>, 






P 


:t^ 


o^ 


k4 


w 


ca 


hJ 


J 








_) 


a 






•^ 















OJ ^ O) 



C3.M p^ o t; >•. c 



Spa t« '-p^'oj'o >■— ^Eq^kT ^ £ ^ 









1 




■n 




-a T3 


+J 




is 


ui 




V 


-tJ 


ii; ii 


















o 


Pi 


"3 


a 
u 
o 


Di 


"o 
> 




o "o 

> > 






Pi 



Qi G) <D OJ OJ 

bo bo bo bo bo 

C C c q c 

nj aj nJ nJ oi 



f^ 2 
o 



CO o o o o o 



3 <= 



O 



o "" 
O 



^ ° c 

(5 " " " 



FL, Pi 



<u /li o .5 o 



Pi pq 



3 •::; -s 



g u o 



1^ ^■^ _n OJ ^ 



<" o p. -5 S ^ 



> > 



>^ '2 S .2 > o 
Pi Q > 



C > 60 ^ r; 

«i ■ „ tj .2 

J- -d 32 .-S ►^ 

Pi Q > 



i <u <u 
60 Pi Pi 






856 



FOOD INSPECTION AND ANALYSIS. 



Pi 
o 
1-1 
o 

CJ 

>^ 
e^ 
Q 

fa 
o 

Pi 
o 

I— I 

> 

<: 

w 





u 

0) 




&> 




u 








& & 




4) 
















rt ^ 


0) 


M 


U (U 




lU 


60 t30 


OJ 


o o 


O 


60 


(U (U (U 


O V V 


4> 


60 -d 


gz ° 
2 ^ o 


•d 




^? 


bO 


C 


bc ta 


60 


C . 


c 

01 


III 

cfl (u i 

1; 60 60 

O c c 


60 


C 


60 60 60 


60 60 60 


60 


c -d 


0) 




C 


c« 


c c 


c 


^ M 


C 


rt 


C C C 


C C C 


C 


Oj 4J -W 


.2 IH 




'^ O 


rt 


^ 


cs ca 


-G ^ 


nJ 


0) 


* 






rt 


^ I- ^ 


k^ 4) 






o 
o 




X J3 
o o 

o o 


S o 


J3 
o 

O 




o 


o 


o 

4) 


^ ^ ^ 
o o o 
o o o 


X J3 J3 
o o o 

o o o 


J3 
o 

o 


" >. 2 


5 13 
^ 






■z 


3 


■z z 


.J>Z 


3 ^ 

3 


3 


o o 


2; 


3 


z 2 2 2; z z z 


















c 


















fe 






d 
o 










•d 


















■d 


o 




(A 

V 

M 


s'^ 


o 


_a) 


<U OJ 


o V 


V 


(U 60 
60 


0) 


7, M 60 

Sec 

i "• S 

60 o O 

S "d -d 

U V V 

o pti »; 


4) 




4) <U U 


4) U 4> 


4) 


60 ^^ 


"3 
>.'d 


•d -d 


.2o 
"•a 


1 ^ 




60 60 
C C 


i 
60 

c 


^ -d 


c 

ID 


60 
C 


■*-> 


60 60 60 
C C C 


60 60 60 

C C C 


60 

C 


nJ 60 +^ 


U <U N 


4) 41 


! !° 

2 2-5 
O o g 


'C 'C 


(2 


^0 


i 


J2 ^ 
u u 

o o 


13 L'^ 


o 


o -d 


o 


O 


a! 
o 


X X j:: 
o o o 

o o o 


j:: j:; x; 
o o o 

o o o 


o 
o 


o nl o 




"o "o 
Q Q 


u 

o 


■Z. Z 


P> 


"3 
Q 


60 


3 


g 




Z Z Z Z Z Z Z 


4J ^ 




"o 


ffi 




























s 




o 














W 






















^ 






































































•d 
































& 


















^ 














^ 


& ^ 


5 4> 


4) 


Q 
"o 

m 

a 
o 

o 

<u 


«<: 

p 

O 3 
CO 


4-> 

O OJ 


u .S'o 


*^ 3 
•o « 

> 


+-> 

> 


>> s 

O JJ 

3 




•d T) 
o a) 4) 
60 >- '- 

C -M *J 
ci <D <D 

O -2 .2 
> > 


60 

C 

2 

o 

"3 


'c 

e 


o _o 

Vi ^ 4J 4) lU 4) 
" J* 60 60 60 60 

r , c c c c 

4) 4) cS cU ca a! 
60 60 t-" ^- *- ^^ 

c c O O O O 

rt ci 
u *-. 

o o 


o 

"3 
>> 

c 

& 

o 
l-i 

J3 

_4) 

"a 


o o 

"3 "3 
>• >> u 

& & -d 

O O 4) 

3 3 


•3 M 

c >• S 

r 1 rt 

p C J: 
2 & ° 
•? S3 

■d ffl -d 

(5 S 

|(2 


2:§ 
41 

^ S 

■d & 

s £ 

ca pq 
Pu 
















Q 














PU 


CL, (L, 


M 






^ 
























T3 
4) 


•d 


•d "d 


1. 
S 

s 

>. 4) 


OJ 

1 CJ 




•s< 




« 


•o -0 


Td (u 




§5 






0) 
60 
C 




o _o 


X! ^ O 


2 

o 


.2 .2 

o o t. 




4) J3 




"o 






Pi 




4) C C 

See 


n) 
o 

& 


o 


"3 "3 ^ 
>. >. o 

4> 4; ^ 
60 6D .^ 


III 


o 

4) 

■d 


o ° fe 

OOP 

41 0) O 

•d TD ^d 


—, SO i 

^ S ?P 
p^ 2 g 




C O 
O u 




_3 


O O o CJ 

> > > (^ 






O W PQ 


'3 


>< 


S 2 




o 


11^ 


S 




o^ 












o^ 






>- 




O O 


_s 


g 


J^ 


2-s 






K 
























< 


< < < 


S ftH 


PU 


o 
o 






o o 






•d 








"d 


"d 

(u -d -d 


•d "d ■£ 


o 








•o 


^ i 




"3 "3 


& 5 






^ & fe 




4J 


t. (U D 
' Ih (-1 


V V.2 


"3 


fe. 4) 4; fe 4J J, 

^ 2 2 g 2 -1 
>H o o >« o > 


c 




o B 
:s c 




60 60 


o & 

=3 o 


•d 


V o 
60 S 
C « 




>. o o 

1^^ 


T3 
4) 




^ -s t; 
c ii iJ 

2 .2 .2 


4J +J '> 


i 
60 

c 


•:- 41 


o 






oi rt 






O 








> o > > > > »; 


2 




^ 


S 


o 






OO 










o 










o 




;^ 


































W 




o 

3 C 












& 




& 




& 


& fe & 




o 
>. 

_4J 


5 ^ ■" 
5 >. V 

"5 ii so 

_4) a rt 


& & 


c 


o'5 


-4J 

■> 1 


c 


■q "o 
> > 


•a 

4i 3 


o 

> 


o 




O -W ■!-> 

s; o o 

rr> 

60 t3 "d 

C 4) CU 


o 


o 
"3 


o _o o 

"3 "3 "3 

c c c 

& & & 


4) 4) 4) 
60 60 60 
C C C 

u u u 
O O O 


a ^ 

2 fe Si 
00c 


& 2 

Xi 

^1 


Pi 


CQ 




> 




o 




Qpi Pi 




o 


o o o 




? 
dl 


£ bo 


4) I-. 


"3 


•5< 












m 




o 




m 


CQ PQ n 






o 

> 


>. 


>< 


^ 


a ^ 


* r^ 


lO 00 


N M 


p) 


(V5 o 




o o o 


M 


~ 


^ t» 00 


O M ro 


p) 


ro o ^ 


N. 00 


>* 00 


. c 




■5 m 


Oi 00 


a o 


o 






M N vO 






►H tH M 


N N CI 




* ro 


M VO 


>0 ro 


o y. 


ro 1- 




* 


* M 


M 


•q- lO 




N M 


lO 


lO 


1/) le >n 


lO to lO 




lO 


t", * ■* 


■* 'I- 


^5 












* 
* 












« 






» * 

* 

* 









































ARTIFICIAL FOOD COLORS. 



857 



O 

< 

w 

H 



Q 

p 

o 

p^ 
o 

(n 
f< 
O 

o 
u 

>^ 

Q 

fa 
O 

P^ 

o 

t-H 
> 

w 













•a 




•0 -d 


















<u 




0) 












•a 


D 1) _, 

bo bo flj " 










■d "d 




u 






C C bO S 
cij rt c T 


lU 


boii 

tH t. C O 

^ ^ "^ > 
"3 "5 -g _ 


_ 1- V. 1- 

T) 0) OJ QJ 


u 


CL> <U U U 
N N <U « 


u t. 3 3 


3 






o 


(U (U " g 


3 
S 


W p^ CL( CL( 


■d -d 


0000 

° "S ^ ^ 


^ >, 






6^ 


o 

Q 


•;3 73 o u 




'^ O 3 

■2 





B E 


1 s;^ >;>;>: ||«§ 

U CO CO 




< 








"3 




< < 










d 








•o 














o 








f 














s'-s 


•a 


Si g y -s 






•d -d -d 


•d -d 


•d -d 


^" Ui 1^ L- 

oj u 53 S 


1H 


:3':=: 


<u 


g IS bo JJ 




lU _4) ^ 


4) 0) 4) 




<it <D U U 


T5 5 3 3 


_3 






'C 


S e s ^ 


C 

(U 


.— »-• "o ,o 




N _N 




3 3 -5 -S 

•a T3 j3 XI 


^ 3 


'cJ 'C 'u 'C 


'C "C 


■C 'C & & 




c^^ 


o 
o 




O CL, lU S 


0) _o 
0^ "o 


_o 






"o "3 ^ ^ 


_>>>>_>•>' 


s^ 




O u 

>> 


o 
Q 


~ ^ -5 ^ 
.•s P 2: o 

(J 






QPOQOQO 


5 5 -c .c 
w 55 55 55 


55 




ffi 








Oh 












^ 










































•T3 










■d 


•d "d 




•d -d 






Q 
"o 






0) & 3 


■d 


91* u 


c 


■S "S 


c c 


V c fe a 


& & 




4J O 


3 




•d "3 .2 60 


<U l- 
3 >> >. 

Q 'C r. 

<u m 


_o 


fj c c 
"d T) 


c & - 
& 2 =5 g 




"3 '3 


o 
ta 

Pi 




[1< 




3 


"3 "a! 


E S 


2m >^s 


> >. 












<: 


2 2 




< < 










'a> 


o 

13 bo 


Id 


T3 

fe .2 

•d b 0) 


<u S -d -d 

3 P 0) 0) 




•d "d 

.2 .2 D a> 


•d 








>> 


>> c 


0) 


<" :S 5 3 


"S "S 


_o vH "C 


(U 






a! " 
O 1- 


i 


i 5 (U (u 


bo 


.2 -3! 3 

1 OJ 4J 


0) fe "o 


'S ■§ 


j5 J5 


t-. 0) 0) 

So £ c c 


bo bo 






§ IP s s 


01 


•s ?i-« iJ 





•« "« fe s 


2 00 







o 

"is 


o i; 


O 


E >< 




i^ -S -d -d 
"« "« 
C C "i "^ 







w 


0. 


O, 




< 






< < 








"o 
o 

Q 


g 


XI (U o V 


_3 


l-S 3 S 

2 f^ s s 


•0 

« " ^ ^ 
(S -s =5 -3 


4-5 +j 

_a) a; 
■3 
> > 


g ^ g 

P C3 C 

3 •« -d 


5 5 -d 

•3 -3 S -d 

'^ '^ « s 

01 lU 4) ' 


•d -d 
V V 

(u i 
3 3 






O p^ pq > 




> 




S rt (S 


£ 2 > m pq PQ 1 




o 
"o 
O 
















00 


















^ 








o 






















3 d 








r* 


d 






fe fc 


a c - 




x: o 




J . . 


•d 


S c 


fe „ 









& & 




1^ 


& 


J2 -. 0) OJ 

t/i (D c; ^ 

J^ bfl bo (-. 

rt ^ w 

Soil 


^ S S 

C Vh (D 


& & 


fe fe C C! 


"3 "3 fc fe 


2 2 




° ° ^ 3 5 

g g ^ s s 


o 

Ih 


<U XI -^ ^ 




_o g g 

'S 'oj "cj 'OJ ^^ t-t 

>H >H >< >H pq cq 


>. >% 



X2 X3 

— ° 
"3 "3 




J 






















^ 


M 


M vO O t~ 


N 


00 Oi 


•* 00 10 




t~ 00 J^ M 


I^ 00 i« Oi 


Tf N 




. 13 


f^ 


^ i^ -^ r* 


vO 


vn a ifl ro 


00 ^ N N 


Ifl iO 


« <M 0\ 


M W Ol 







o Si 


■<* 


■* t « M 


Ifl 


-^ <) 


10 •* ^ ■* 


rf ■^ 


^ ■* w N 


10 ■* 


10 10 




2^ 


* 








* * * 


* 


* * * 




* 




« 








* * 


* 


* 




* 












4f- 


* 






* 




"" 





















858 



FOOD INSPECTION AND ANALYSIS. 



o 

I 

H 

W 
O 

< 
w 
Pi 

a 



Pi 

o 

o 
u 

Pi 

Q 

o 

P^ 
o 

> 

w 
w 
m 





0) Ov 


V 


(L 


0) 


<D 


oJ 


0) 

bo 


•d 






bO 






3 
bo 


bo 


<a 




60 


SO 


M 


bo 


BO 


c 


•d' 




C 


bo 


"ca 


C 


C 


bO 




"2 h ° 


C 


c 


C 


C 


C 


ca 


£ 


P 


3 


ca 


C 


ft 


ca 


ca 


a 




B n) l4 

< d 


rt 


cfl 


rt 


d 


en 


^ 




u 


3 


x: 


ca 




x; 


Si 


ca 




^ 


^ 


^ 


X. 


Si 





ft 


CL) 


(J 


Si 


>. 






si 




o 
o 


o 


o 
2 


o 
Z 






ii 


01 

Q 


3 

s 


•d 

4) 
Pi 


■4^ 





1 


_4J 


jj 








M 












|j 








'.J 




s 


^ 


J 




c 


3t3 C 


Ofl 


6 
c 


bo 
a 


bo 
C 


aj 

bo 
C 




■d' 


13 




4; 
■d 


3 
bo 
c 


ft 


•d 


•d' 


I 

3 
3 




O O -tJ 


C 


J3 








"3 
>> 


^^ 


<u 


3 

3 


ta 


•d 


4J 


£ 


3 


(U 


W £ 3 


x 




o 


u 


y 


<u 


ft 


It 


Tl 





ca 


3 

> 


^ 


4J 






o 
o 


(U 


_a) 


.2 


.2 


bo 
R 

ca 


01 
4) 

Q 


3 

s 


•d 

V 

Pi 


Pi 


ii 


S 
c 


3 

> 


_4) 

3 
> 


% 


HC 




J 


Ij 


3 


J 


t5 










3 


£ 








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* 







ARTIFICIAL FOOD COLORS. 859 

Separation of Colors by Immiscible Solvents and their Identification. — 

Mathewson' s Method* — (a) Preparation of the Solution. — Make a 0.05 
to 0.01% solution of commercial colors. Take up randies, syrups and other 
saccharine products in hot water. Evaporate or dilute wines and liquors 
to less than 10% alcohol content. Extract fruit products, flesh foods, and 
similar products with 80% alcohol containing a very little acetic acid to 
remove basic colors, cochineal, etc., and the residue with 65 to 80% alcohol 
containing 3 to 5% of ammonia. Boil both extracts until the alcohol is 
reduced to less than 10% and ammonia is nearly removed from the second, 
then combine. It is often preferable to add strong HCl directly to strongly 
colored jams, sausage, etc., extract with amyl alcohol, and shake with 
salt solution and other aqueous solvents. For procedure with cereal 
pastes see pages 366 to 369 and with butter and other fats, pages 557 to 560. 

Whatever the method of solution treat the aqueous liquid with sodium 
carbonate if acid, or with acetic acid if alkaline, until neutral or slightly 
acid. Suspended matter, other than precipitated dye, should not be present 
in considerable amount. Too great color concentration (over 0.1%) of 
food extracts is rarely encountered. Large amounts of sugar, glycerol, 
etc., affect somewhat the solubilities. 

(b) Separation. — Since most coal-tar dyes are accompanied by sub- 
sidiary dyes those present in largest amount should be first carried through 
until identified. Colors of fruits and flowers being usually unstable, 
especially in alkaline solution, are best tested for in a separate portion. 
The table on pages 868 to 875, based on 0.01% concentration, is more 
useful than an analytical key. The following outline is for complicated 
.mixtures. Ordinarily the analyst will vary the procedure according to 
probabilities. A preliminary dyeing test is advisable. 

1. Add to the solution NaCl equivalent to 5 to 6% and shake with 20 cc. 
or more of amyl alcohol, repeating the treatment once or twice if considerable 
color is extracted. Wash the combined extracts, if colored, once or twice 
with small portions of 5% NaCl and add the washings, if also colored, 
together with any suspended matter, to the extracted solution. 

2. Add to the extracted NaCl solution half its volume of concentrated 
HCl and shake with amyl alcohol as before. If the extract is colored wash 
once with 4N HCl (i : 2) and proceed according to sec. 6; if colorless, 
even after adding NH4OH, reject as most strongly sulphonated azo colors 
are absent. For procedure when naphthol green is present see sec. 18. 

* Loc. cit., pp. 8-53. 



860 FOOD INSPECTION AND ANALYSIS. 

3. Make the extracted acid NaCl solution, which may be nearly color- 
less, slightly alkaline with NH4OH, then slightly acid with acetic acid. 
If then colorless reject as strongly sulphonated triphenylmethane green and 
blue dyes are absent. If green or blue shake with enough dichlorhydrin 
to give a lower layer after separation of 20 cc. or less. If a blue color is 
extracted repeat once or twice, wash the combined extracts with a little 
NaCl solution and examine according to sec. 5. 

4. The solution after the preceding extraction may still contain natural 
colors (fruits, etc.), acid magenta (No. 462), and large fractions of acid 
yellows (Nos. 8 and 9) although these latter are chiefly extracted from the 
acid solution (sec. 2). To detect No. 462 apply the nitrous acid test, dye 
test, etc.; to separate it add HCl until over N/4, allowing for ammonium 
acetate, shake with anilin, wash the extract with 5 to 6% NaCl in N/4 
HCl, and remove the dye with water. Before testing make alkaline and 
remove the dissolved anilin with several portions of carbon tetrachloride 
or benzene. Commercial acid magenta contains various sulphonates and 
yields derivatives of greater solubility in organic solvents. If the color 
of the extracted acid salt solution is entirely due to Nos. 8 or 9 it will be 
orange red, becoming yellow on neutralization. Nitrous acid, etc., give 
characteristic reactions. 

5. Dilute the dichlorhydrin extract (sec. 3) with 3 to 4 volumes of car- 
bon tetrachloride and remove the color with a few small portions of water. 
Shake the combined washings once with carbon tetrachloride to remove 
dissolved dichlorhydrin. The washings may contain higher sulphonated 
triphenylmethane dyes or sulphonated indulin, with large amounts of 
subsidiary products. Their solubilities cannot be definitely established. 
Compare their properties as given in the tables. 

6. Wash the amyl alcohol extract of the acid salt solution (sec. 2), 
if colored, 4 to 5 times with N/4 HCl, keeping the washings separately and 
reserving the washed solvent for treatment according to sec. 7 or 8. Nos. 
108 and 692 predominate in the first washings, which owing to HCl dis- 
solved in the amyl alcohol, is high in acidity; Nos. 106, 107, and 94 come 
out chiefly in the third. Vary the procedure according to probabilities. 
The color of the washings will usually show if more than one dye is present 
in considerable amount. Separate Nos. 106, 107, and 94 from No. 108 by 
2N HCl and amyl alcohol and from Nos. 692 and 8 by 8N H2SO4 and amyl 
alcohol-gasoline (i : i). Wash Nos. 106, 107, and 94 out of the latter 
solvent with a little water, add at least half the volume of concentrated HCl, 
re-extract with amyl alcohol, remove H2SO4 with a few portions of 4 to 6 



ARTIFICIAL FOOD COLORS. 861 

N HCl, and finally wash out the dye with water and evaporate to dryness 
on a water-bath. Test with cyanide, etc. Separate >the dyes in the H2SO4 
solution with anilin (page 868). Use anilin and 5 to 6% NaCl in N/4 HCI 
to separate No. 94 from Nos. 106 and 107, removing the anilin from the 
solutions, after making faintly alkaline, with carbon tetrachloride. No. 692, 
which like No. 8 is of indefinite composition, may be separated from azo 
dyes by cautiously adding powdered sodium hydrosulphite (Na2S204) to 
the acid solution, then shaking with air to restore the blue color. Reduction 
by this reagent in an ammoniacal solution, avoiding an excess, destroys 
Nos. 106 and 107 while No. 8 is merely converted into the hydrazo compound 
and may be restored by shaking with air. No. 692 is destroyed by warming 
in an acid solution containing a little urea and a drop of 7% sodium nitrite 
solution, while Nos. 106, 107, and 108 are scarcely attacked. Dyes of 
this group are much used in foods. 

7. Wash the amyl alcohol extract with N/16 HCl same as previously 
with N/4 HCl. Omit if Nos. 14 and 188 appear to be absent. 

8. Dilute the amyl alcohol with an equal volume of gasoline (sp.gr. 0.65) 
then wash successively 2 or 3 times with N/4 HCl, N/16 HCl, N/64 HCl, 
N/64 C2H4O2 and N/64 NaOH. Wash with the alkaline solution even 
if the preceding appear to remove all the color as some weakly acid 
dyes (mostly of other groups) are nearly colorless in neutral or acid solvents. 
Study the solubilities as given on pages 869-872 inclusive. When the 
fractions appear to contain more than one dye, refraction until pure. 
Test for No. 4 (nearly colorless in acid solution) by adding HCl to the first 
strongly acid washings until 2N, shaking with washed ethyl acetate, and 
treating the latter with alkali. If a yellow color is obtained treat in like 
manner the remainder of the fractions containing it. Reserve the N/64 
C2H4O2 and NaOH washings until the neutral NaCl amyl alcohol extract 
has been tested, as this will contain the bulk of the dyes, or mix these wash- 
ings with the corresponding ones of sees. 11 and 12, or omit these washings 
entirely and mix the amyl alcohol-gasoline extract after washing with N/64 
HCl with the similar mixture of sec. 10. 

9. Chemical methods of separating closely related dyes: (i) cyanide test 
(page 866) for separating R-salt derivatives (Nos. 55, 56, 65, 15) from mix- 
tures with isomers; (2) reduction and subsequent oxidation methods for de- 
struction of azo and nitro colors in presence of most other colors (see pages 
866 and 867) ; (3) cautious reduction in Na2C04 or NH4OH solution 
whereby oxyazo dyes tend to be attacked more rapidly then aminoazo 
dyes, allowing for new dyes formed by partial reduction of polyazo or 



862 FOOD INSPECTION AND ANALYSIS. 

nitroazo derivatives; (4) bromine oxidation (page 864), halogenated fluores- 
cin derivatives (fully substituted) being more resistant than most other 
colors in acid solution and No. 4 than most azo dyes in alkaline solution, 
but the test is seldom so satisfactory as extraction with ethyl or amyl ace- 
tate and fails when Nos. 6*2, 64, 65, and 188 are present owing to blue 
substances formed. 

10. Dilute the amyl alcohol extract of the NaCl solution (sec. i), which 
contains practically all the basic dyes and most acid dyes of low sulphur 
content, with an equal volume of gasoline, wash a few times with N/64 
HCl, and treat the washings, if colored, according to sec. 11. Wash the 
extract with N/64 C2H4O2 and treat the washings according to sec. 12; 
then, to remove eosins and (in general) unsulphonated, water soluble, 
acid (phenolic) dyes, wash with a few portions of N/64 NaOH and treat 
the washings according to sec. 13. Finally wash once with very dilute 
C2H4O2 and, if still appreciably colored, evaporate to dryness on the water- 
bath, and examine the residue according to sec. 14. 

11. Make a small portion of the N/64 HCl extract (sec. 10) alkaline with 
NaOH, shake with ether, and treat the usually colorless ether solution with 
dilute C2H4O2.* If a color appears, indicating basic dyes, extract the 
alkaline portion once or twice more to learn if acid dyes are also present. 
In the presence of both, add NaOH to the main portion until of normal 
alkalinity, shake with ether, and remove the basic dyes from the combined 
ether extracts first with N/64 C2H4O2 and finally with dilute HCl. Omit 
this treatment if acid dyes are absent, since most basic dyes (especially 
auramin) decompose in alkaline solution. The basic dyes may be further 
fractioned from amyl alcohol with dilute HCl, from ether with dilute alkali, 
etc. After removal of the basic dyes with ether add to the alkaline solution 
HCl to normal strength and shake with amyl alcohol-gasoline. If a color 
is extracted it will probably be a minor portion of one obtained according 
to sec. 8 and may be further fractioned with the main portion or separately. 
Reduce the N HCl to N/4 by adding NaOH and shake with carbon tetra- 
chloride-dichlorhydrin (3 : i) to extract lower sulphonated triphenyl- 
methane dyes, then add more tetrachloride and wash out these dyes with 
water. 

12. Fraction any monosulphonated monazo dyes in the acetic acid 
solutions of sec. 10 (chief part) and sec. 8 (small part) with amyl alcohol 
and N NaCOs or with ether and dilute HCl. 

*Witt, Zeits. anal. Chem., 26, 1887, p. 100; Wcingartncr, ibid., 27, 1888, p. 232. 



ARTIFICIAL FOOD COLORS. . 863 

13. The main part of the eosins and unsulphonated water-soluble dyes 
are found in the N/64 NaOH of sec. 10. Fraction the eosins between 
N NaOH and amyl alcohol or amyl alcohol-gasoline (3:1). Acid dyes 
with basic tendencies (Nos. 510, 95, etc.), differ from the others in being 
extracted in smaller amount from strongly than from weakly acid solutions 
(pages 871 and 872). The amyl alcohol-gasoline solution (sec. 8) may 
also contain these dyes although usually in small amount. Most natural 
colors appear in the N/64 NaOH solution. 

14. Moisten the amyl alcohol-gasoline residue (sec. 10) with a small 
drop of alcohol, add ether, and N/64 HCl, and shake. If the acid layer 
is colored (rhodamins, possibly basic dyes) wash the ether with further 
portions. If the ether is colored, wash a few times with 4N HCl, neutralize 
the washings, and treat according to sec. 15. Finally wash the acid out 
of the ether with water, evaporate to dryness on the water-bath, and treat 
the residue according to sec. 16. 

15. Dissolve the oil soluble dyes from the neutralized solution (sec. 14) 
in gasoline and fraction with 70 to 90^ methyl alcohol (page 875). Ortho- 
tolueneazo-/3-naphthylamine, although decomposing rather rapidly in 
strongly acid solutions, like its lower benzene homologue, is extracted slowly 
by acid from an ether solution. Probably the dyes undergo rearrangement 
before forming water-soluble salts, both forms decomposing by prolonged 
standing with acid. 

16. Add to the ether residue (sec. 14) methyl alcohol, water, and NaOH 
solution, sufficient to make the alcohol strength 8c% and the alkalinity 
N/4, and shake with gasoline. No. 666 anda-naphthol derivatives remain 
chiefly in the alkaline liquid. Treat the gasoline again. If necessary, then 
according to sec. 17. 

17. Separate sudans further with gasoline and 90% methyl -alcohol. 
Shake the gasoline solution with 85% phosphoric acid to which has been 
added 10 to 20% of H2SO4, thus separating from oily impurities although 
with probable destruction of some of the dye. These colors, like those 
of sees. 15 and 16, may be almost quantitatively removed from gasoline 
by 90% phenol and purified by redlsolving in alkali and again taking up 
with ether or gasoline. 

18. To avoid decomposition of No. 398 In acid solution, extract the 
neutral NaCl solution with dichlorhydrin, wash once with benzene to remove 
the dissolved solvent, make N/2 with HCl, and shake with anilin, adding 
the latter first. Fraction from the anilin solution with N/4 to N/64 HCl 
containing 5 to 6% NaCl. 



864 FOOD INSPECTION AND ANALYSIS. 

(c) Bromine Test. — This is useful in examining the fractions for azo 
and azin dyes in the presence of natural colors. To 5 cc. of the solution 
(0.005 ^o o-oi%) S'dd drop by drop slightly more 1% bromine water than 
is required to destroy the dye, then a few drops of 3% hydrazin sulphate 
solution. To half of the solution add a few drops of freshly prepared 
10 to 20% alcoholic a-naphthol and an excess of Na2C03; to the other 
half only Na2C03. With azo compounds sodium formate may be sub- 
stituted for the hydrazin salt. The reactions belong in classes as follows: 

A. Azo dyes which with bromine in acid or neutral solution become 
colorless, pale yellow or orange and with hydrazin sulphate are colorless, pale 
brown, or pink, the color being more marked when nearly neutral. With 
a-naphthol and Na2C03 a pronounced color appears but with Na2C03 
alone no marked coloration. If the first component of the original dye 
was an unsulphonated amin the new color (e) may be removed by ether 
from the alkaline solution imparting usually an orange color changing 
with a large excess of strong HCl in most cases to violet or blue; if the 
new dye (w) is sulphonated it will not be extracted by ether. The new 
dye may be fixed on wool from a suitable solvent and identified by spot 
tests. The following dyes belong in this class. A (e) : 14, 21, 20, 53, 55, 
56, 146, 154, 13, 54, 157, 26, 10. ^ or C (e) : 7, 18. A (w) : 108, 8, 9, 89, 
399, 106, 94, 105, 164, 169, 163, 170, 84, 328, 85, 86, 97, 139, 95, S8, 92, 102. 
A or AA (w): 107, 93, 103, 139, loi. A or C: 197, 201. A (imperfectly) 
318, 287, 220, 269, 240. Of the oil soluble colors in the tables all belong 
in class A but quinophthalon which in 60% C2H4O2 gives reactions of class 
B. Class A also includes 277 and 78, the latter requiring addition of 
some alcohol before a-naphthol. 

A A. Azo dyes reacting like those of class A in HCl (N/2 or above) 
solution. In neutral solution the reaction is less trustworthy as other 
oxidations take place, blue and other colors being produced with Na2C03 
alone which, excepting 62, 64, and 65, is less intense than those of the origi- 
nal dyes. Bromine bleaches 62, 64, and 65 in N/4 Na2C03 but an intense 
blue appears on adding hydrazin sulphate. A A (e) includes 62, 64, and 
65, AA (w), 188. 

B. Azin derivatives, etc., bleached by bromine in neutral or acid solution, 
the color being restored by hydrazin sulphate. With typical members the 
color may be again bleached and restored. Na2C03, also a-naphthol and 
Na2C03 give no change other than that shown by the original dye with 
alkali. Class B includes 604, 605, 667, 606, 534, and 562. 546 reacts im- 
perfectly and 584 belongs to class B or C. 



ARTIFICIAL FOOD COLORS. 865 

C. Dyes giving precipitates at dilutions as high as o.oi%. This class 
includes most basic dyes. 

D. Dyes giving marked color changes in neutral or faintly acid solu- 
tion. As the color usually appears w^ith a trace of bromine and is destroyed 
by an excess the reactions are unsatisfactory. Hydrazin sulphate produces 
no color change except that due to removal of excess of bromine. The color 
v^ith a'-naphthol plus Na2C03 is the same as with Na2C03 alone. Most 
yellow colors become brownish, other colors usually ill-defined. In acid 
solution the dye, as a rule, is merely destroyed by bromine same as with 
class E. Class D includes 434, 435, 436, 480, 507, 438, and 433; class 
D or C, 496, 427, 428, 505, 499, 504, and 502. 

E. Dyes similar to those of class D but showing with bromine no change 
other than bleaching. Class E includes 439, 440, 602, 692, 398, 4, 706. 
710, I, 329, 483, 512, 515, 516, 517, 518, 520, 521, 523, 2, 3, 6, 707, 468, 
464, 442, 476, and 658, class E or C, 650, 425, 426, 451, 452; class E or D, 
491, 462, 639, and 448. 

F. Halogenated fluorescin derivatives and similar dyes very resistant 
to bromine. Non-fluorescent iodine compounds tend to become yellower 
and develop a green fluorescence. No. 510 gives eosin. 

((/) Nitrous Acid Test. — Most common coal-tar dyes in dilute solution 
do not react readily, but some show marked changes due to diazotization 
of free amino groups, formation of nitroso compounds, or direct oxidation. 
To the water solution add 2 to 3 drops of strong HCl and i to 2 drops 
of "]% sodium nitrite solution. Add i cc. or an excess of 3% hydrozin 
sulphate solution, after standing a few minutes in case of blue and green 
dyes. To half of the solution, after \ to i minute, add a few drops of alco- 
holic cK-naphthol solution and Na2C03 to strong alkaline reaction ; to the 
other half for a check add only Na2C03. The following gives reactions; 
others in the table pages 868 to 875 show no color changes except those 
due to the acid or alkali. 462: NaN02, blue, then colorless; a-naphthol — 
Na2C03, orange. 439: NaN02, yellow. 491: NaN02, violet (slowly). 8: 
NaN02, much paler; a-naphthol — NaCOs, deep blue (Hesse). 9 : NaN02, 
much paler; a-naphthol — Na2C03, red (Hesse). 89: red solution; NaN02, 
yellow; hydrazin sulphate, red again. 692: NaN02, slowly oxidized to 
yellow isatin derivative. 398: NaN02, brown. 21: NaN02, slightly 
darker; a-naphthol — Na2C03, dull green black. 318: NaN02, pale 
and redder. 480: NaN02, slowly attacked. 84: NaNO 2, redder. 507: 
NaN02, bluer. 85: NaNO 2, paler. 95 and 88: HCl, crimson; NaNOo, 
yellow; hydrazin sulphate, crimson. loi: NaN02, paler. 220 and 229: 



866 FOOD INSPECTION AND ANALYSIS. 

NaN02; slightly paler. 562: scarcely attacked; in 50% acetic acid 
NaN02 gives same change as bromine. 584: NaN02, blue; hydrazin 
sulphate, red, 448: a-naphthol — Na2C03, wine red; in acetic acid solu- 
tion, NaN02, first blue, then colorless. 427: NaN02, reddish. 17 and 
18: NaN02, paler; a-naphthol — Na2C03, redder. 505, 499, 504, 502: 
may appear bluer with a-naphthol — Na2C03. 16: NaN02, slowly de- 
stroyed. 7 and aminoazotoluene : NaN02, paler; other reagents red. 

(e) Cyanide Test. — This is based on the reaction, discovered by Lange, 
of the second component of certain ortho-azo dyes with KCN the 3-sulphonic 
group being replaced by cyanogen. Heat 10 cc. of the color solution, 
I cc. of 20% KCN solution, i cc. of 20% NH4CI solution in a test-tube 
in a boiling water-bath for 5 to 8 minutes. Carry along tests with known 
dyes at the same time. The common nitro dyes become brownish or red- 
dish, certain azo dyes react as follows : 108 : warmed 8 minutes dye nearly 
all changed to orange or yellow substances; warmed until dark red (i to 2 
minutes), strongly acidified, and washed with 2 N HCl, practically no 
color removed; subsequent washing with N/4 HCl, blue red dye removed. 
Azorubin S. G.: apparently unchanged by cyanide. 106: solubility un- 
unchanged but much color destroyed on long heating; 10 cc, amyl alcohol 
extracts the color from the cyanide mixture acidified with 5 cc. cone, HCl 
and gives it up to N/4 HCl. 107: cyanide mixture pale brown; treated 
same as 106, color remains largely in amyl alcohol; color destroyed on 
long heating, 14, 20, 21, 52, 53, 62, 64: dye unchanged; cyanide mixture 
acidified with i cc, glacial C2H4O2 gives up little color to 5 to 10 cc. amyl 
alcohol. 15, 55, 56, 65: cyanide mixture pale brown; treated like pre- 
ceding dyes, gives up most of the color to amyl alcohol. 

(/) Reduction and Reoxidation. — The reagents are those introduced 
by Green, Yeomans, and Jones. Drop into the neutral solution a few 
particles of powdered sodium hydrosulphite (Na2S204). If no color 
change appears at once, warm and add more reagent, avoiding an excess. 
If reduction and consequent decolorization takes place shake thoroughly 
with air and, if no color reappears, warm and allow to stand a few minutes. 
If still practically colorless drop in a little potassium persulphate. Dis- 
regard slight yellowish or brownish tints produced by air or persulphate. 
The reactions with most of the dyes on pages 868-875 belong in three 
classes : 

A. Decolorized (or nearly) with hydrosulphite; remain colorless (or 
nearly) with air and persulphate: 108, 8, 9, 89, 106, 107, 94, 398, 198, 
14, 20, 93, 53, 55, 105, 4, 56, 62, 64, 65, 103, 139, 164, 163, 84, I, 328, 85, 



ARTIFICIAL FOOD COLORS. 867 

13, 86, 97, 54, 329. 139. 157. 95' 88, 92, loi, 102, 26, 220, 269, 2, 3, 10, 
240, 197, 201, 17, 18; slowly decolorized, 21, 287, 78; bluer, then decolor- 
ized, 318, 169, 170, 146, 154; browner then decolorized, 277. 

B. Decolorized with hydrosulphite but original color restored by air 
or persulphate: 440, 692, 483, 468, 464, 650, 639, 584, 448, 451, 452, 427, 
428. The following are nearly decolorized with hydrosulphite or change to 
the colors noted and the original color is restored with persulphate : nearly 
decolorized, 462, 710, 438; slowly paler, 439, 442; much paler, 480, 510; 
much paler (with excess), 512, 515, 516, 517, 518, 520, 521, 523; pale 
olive, 602; pale orange, 604, 605; pale yellow, 606. The following are 
nearly decolorized with hydrosulphite and the color is partly restored with 
persulphate: 434, 435, 491, 496. 

C. No change with hydrosulphite: 399, 667, 706, 546, 507, 707, 658, 
425, 426, 505, 499, 504, 502. No. 476 is not readily reduced. 

Certain dyes do not belong in any of the preceding classes: 436 becomes 
very slowly paler'with hydrosulphite ; 6 becomes dark, then pale and with 
persulphate pale reddish; 433 is paler with hydrosulphite and greener with 
persulphate; 534 and 562 in alkaline solution become red (slowly) and 
yellow respectively with hydrosulphite and the colors are restored by per- 
sulphate. 



868 



FOOD INSPECTION AND ANALYSIS. 



w 


a 


o 


u 


m 




'^ 






o 


H 




< 


CD 


^ 


Q 


r/1 


m 


^ 




O 


nt 






H 




13 




^ 


<u 


CJ 


cj 






O 
fin 

H 
> 

o 

w 

eq 
I— I 
u 



PH 


l-i 


m 


rt 






CO 


4) 

Tl 


(li 


(U 


O 




►-] 


>> 


O 


OJ 


u 


•o 




-2> 


uk 


■^ 


o 


fi 






z 


CD 


o 


w 


1— 1 




H 


•n 


O 




< 


cl 


oi 


"V 


H 


d 


>^ 


u 


w 


«« 






O^. 






< or. 



Si ^ 






O^ 3 



o n! 3 



S 6-2 iT 



4 ro • "^ O 

^••|oe 









Zn 


a)T3 


00 Oi o 






6 




Fi • 


-o 






o 


i:2; 


o. 




oj :' 




r^ 




o 


o 


"o.ti 










0! . 

Moo 




o 
Z 


O O 


CTi 




•sz 


U 


<^-i 


■^6 


u 


CO 


V^ 


c 

CO 
Xi 




CO 

B 


< 







Off . 
" cO-O 



O 0) OV-C!0 1-i 00 5 

cuic M 'a-°° aZ '^ 
n o t^ Z St^o 

4^h'-i -*j ™ CO o, 

•^2;^^J".z 



. c 



° O " iH 

t/5 •- o a> 
o^Z~ 
Z "1 -" 

^ cO\.<» 



3 u « 
O g'^. rt 

t- ° ^ 

o >^ *^ ctJ 

N 2 "• I" 



S CO O 

.ii C Q) o ■<-■ O 



.5 .-i^ 1 o ^ 
O O) O O 4J <u 

^.° c o q o g 



zz 



... .^ 




-+J 


















^» 


in o'S'^ 






M^ !fl-.:5 




Fff 


""^^fe 


0) 


•3i3 


Z^:2;° 


c 


Z^ 


^ 




•* 



.2 o 



Z-.=i 



o o o 



(U 3 OJ 



M „ Ji — 



1-. uX: \- -^ ;i 



S S S 






CO cO 



-S^-S'S 2 s § 



•* la o <> w 



a, Z ei, 



^ (U 

o»; o .S 
^^^ !o I 
>• ^ ^ 2, Si 

.•-'60'^ 



00 Ov Oi M 



u B 



>" _>^ 



6 -3 



c S o 
0.2 u 

••J C^ 
"MO 

•o 



ARTIFICIAL FOOD COLORS. 



869 






^'^< 



"Oi 



•^ 1= c o S^ 
-=-d h o " •• 



°«2 
7-. 



2; w 






3 


1 Ale 
line ( 
[rom 
Solut 




-^o _ 


tj 


as o 


<3 


<o K 



ZG 





<0 






•2^ 


i^ 






2^ 


z-^ 



h,"^' b 




Z " o 




Z't^ 
















tOw 








•^^1 








gii-Q 




rtT3 


c 


►,-E c 


o 


IS S ca 


c 


•* 














•c c o 






ag 



.E.^ 



_rt-c 



zz 






z^;^ 



QJ O 

>J3 
O . 

•9 •* 

rtvo 

CZ 4J 
ca Vh 

-.6 



J* 2; 



< z 



O^ 3 





(U 














ii 




CUI 








ao 






(D 


>> 


c 




o 




c 










01 




60 




01 


W) 




Oi 




.a 




CIS 


>.& 


^ 


c 


% 


>. 


(U 


. 


x: 


!3 o 




j: 


+J 


S. <a 






J3r5 


o 




A 


cj cm 




3 


o 




+j 


o 


"S 


00 


>- 


►J 


m 


y. 


M 


J 


'4. 


>- 


w 



Oj Q 



O V. g 

o Ola 



;=; OJ 



PiS rt 



0) (-. 

> O 



^ V -r P 



PQ S S 






WWW 



PQ O 



6 E 



•o O 



< < :z; o 



Sm 



Ji O 



•" i3 



?! ^ 



a Ol 



dc a, ft, 2: 



Z,V 



870 



FOOD INSPECTION AND ANALYSIS. 



O 

I— I 

H 
O 

C/3 

m 

O 

I— I 

> 



(4 
O 
hJ 
O 

o 
o 
o 

I— I 
H 
U 





Amyl 
Alcohol- 
Gasoline 
(I : I) 
from 
N/64. 
NaOH 
Solution. 


s 




















lU 




































•* 




















A c c I'd— "^ <- S 


t; 





































■d 




















1 




















. <u 
















4J 




T3 «73 
















o 

2 




'SJS 


















vJ 


•— ; • 




















|S.HS 
















« 


H 
















c 


















3 
O 

a 




z 
















1 










•- it 










> 




(U 

a c 
oj^"^ 








ago 
-2 aa 










rt 




•- a> 


















< ^ 


Z 








2 












-M 








_^ 














































"n 












3il 










2 














vO •- DO 








?° 












--S=55 








^.^=3 












< 


2; 








^rt« 












C 
§ 


4) 








-:i-s^°iL 




































E|.SS!g"i^«2 




























*:> 








g.Q M 60 CTa 4) 












< 


'►J 




















lU 4) 


<u 


(U 


+J Q) 















60 DO 


60 


60 







60 










v a c 


C 


C 


t^ 


CI 








w. C 


00 CD cd 


ci! 


cU 


M 


d 








■»-> S 


S -S >.s-g 


.C 


j: 


> C ,„ .XI JS 


VI 


^ 













u 


Darker, 

nally 
No cha 

Same ai 

Darker 

Darker 
nally 
violet 

Little c 


(4 













.-S --Ti.ti 

2; J w J 




_0J 

"»3 


s 


















fc 




















T) -d .2 














S S >3 60 

.S .a g « 
m w S 


C 

60 


c 

m 


lilt. 1 
>i W K 


t-. 




> 


•d 


■3 
> 




vl 


3 






& s . ^ 


a 

















■^> lU *;> 0) r\ 


?, 










a 







c 

e 


ein scarle 
xtra 

oline yell 
;er solubl 
ein scarle 

rich scarl 

eaux G 

rein yell( 




£ 

CI 















C 

3 


■4J 

.2 


3 

2 




1 




s ^ ^ -s 


u 




w 


2 'B&S .2 S S 


s 





^ 







I 


d v^ 




a 


'u 


N 


'C 


N 




cu clh m 


< 


Ph 


m CQ p^ 


PQ 


<: 


w 


< 




^5 


« N •* lO 


ro 


a 


■<*• t~ .Oi to ■>!• 


-0 


r~ 


00 







10 %o ^o 





ro 


-0 vO t^ 00 


■«t 


00 


t^ 


»^ 




* « * 


M 


M 


M IH M M 


*H 


M 




«^ 




« 


« 




* 








« 
* 




'~' 





















ARTIFICIAL FOOD COLORS. 



871 




o 

Pi 
< 
> 

o 
oi 

H 
> 

o 

w 
« 
u 





Ether 
from 
N/64 
NaOH 
Solution. 


u 




















1 




tj 

►4 












Amyl 
Alcohol- 
Gasoline 
from 
N/64 
NaOH 
Solution. 




•3" 




"o 






^ 


















1-1 




■3 








^ as.2 






_4J 













l-i^Z^ 






E 




E 








< 






CO 




< 






or- 

n- 

on 

ilorid 

from 

on. 








a 





E 




o 














u 


"ca 


















1 tn '^ 


2 


« 














— 01^ -M 


t? 


u ^ a 














>>^ "■ — 


w 


Ethe 
from 
HCl 
lutio 














0)<< „ ■* 


3 



















o 
















t 


6 
































<: 


a 












^-w 


<u 
> 

Pi 


AmylAlcoh 

Gasoline 

(1:1) f roi 

N/64 

C2H4O2 

Solution. 






_5> 






57, more 
than hal 
others le; 
than hal 








3 






" 


■3 E . 

J3 4) J2 
C t^ u 




N, more than 
half; N/16, 
half or less; 
N/64, 
smaller part 





•H^ 


•d "a 


bo 
u 






o--'~— 

2 S W^ 


HI 


x; . 

. 


- .J2 

■Is 


S j;.S" 
^ d 










E 


g^ 


:2;5 


Mj3 4) 


3S 




\myl 

Icohol 

from 

HCl 

ilution. 


■^ -1 
vo^E 














< c^ 


2 "* "" 












1^ d 


CD 0.C.5 


(-• 














S^ci 


■•5 c "'■« 








■(3 










term 
etwei 
edini 
ucce 
roup 


u 






E 










•53JD u) 00 


rt 
















►4 






5 










& 








s 


& & 















m 


_ 




i^S-2 


1 1 


rt 






bor3 
ca >> 


V <u <u 






Orange- 
Yellow 

Violet- 
Yellow 

Scarlet 




c 
ca 


« 0) D 

bo bo 00 
c c c 


°4 

•ss 


rown 
rown- 
■ange- 
ange- 









000 


^6 


«"oo 




"o 








lU 

60 

a 


c 


^Xl 







•S« p^:^ c 


m 




ca 


(ii S 


Resorcin br( 
Bordeaux B 
Metanil yell 
Orange IV 







Alizarin r 
Picric aci 

Violamin 
BriUiant ; 

Rosinduli 


"O 

a; 


l-H 
lU 


.E 4) oj 






6 
■z 






cm 

a 

i-i 



(u bo bo 
C C 

ca ca 

^ U li 

000 


1- 




gj 


n t-00 vO 


•* 


IS 


f^O r^ 


to 


t^ t^ irioa 






■* N 


10 


00 


tH 00 Ov 


10 c^ 


r<5 ifl OiOO 




m »o n -0 


t-i 




* * 


CO 


M M* 




« 






* * 




























1 



872 



FOOD INSPECTION AND ANALYSIS. 







Amyl 
Alcohol- 
Gasoline 
(3 :i) 
from 
N NaOH 
Solution. 


• 








0) 


3' 
ft 


id;:; 


C 
n! 

lis 


So 






















> 


a, 


> 


ffi 


2 












t; ffi c 












"s 






































_>. 










.a 










J 


+-» 

ft 




c« ft 

►J 




2"^ 
































^ u 




a 






















•3^ 
>>o 


•0 


1 






^ -M O 
















— ■« 




2 ^ 


m 




CO 


►,« c 
















— "-^ 


-2j3 


■*^-.^ 


g 






2 
















2 


2 


2" 


O 




^ 


_^ 


^ 




















P-H 




o t 


w> 






















H 


<u 
o 

2 


< U3 C « 3 

-r- rt M c -7 r-H 


a 


C4 ■'-< 

oi-o5 


















O 
I— 1 




Z.2Z 




. « (D C) 
















% 


a 

3 

o 
E 
< 




>* 




Tl- 


2; 
















o 


"o •* 


J5 




"is 




















> 

(5 


►4 




2 


















> 


"o 


^ 




_>. 


IlL 
















w 

P5 

U 




< 






C 




















•a =3-^ 






















in 




^o S 


r- "^ (-• 






















1— 1 




el iC.2 

<3 o 


rt ^ 2 
to s 
















































"3 Q 

o 1 o';3 


"rt 








"iS 




01 



a 




"3 










o 




— sz ° 
< 


o 








4J 




u 






at 














< 






hJ 


2 




K 




2 




















& 


& 


& 


& 




& 


c^ 














_o 


_o 





_p 




_g 


c 




























;jh 




U CO 








"3 


"oj 


CJ 


__ ^ "s 




'3 


^c. 


o 

§ 

1— 1 

H 






Pi 




•d s 
a; 4) 


>. 

cm 
C 

2 



s 


G 

l-dTJ-o-d 

C 4) <U « 


■dT3 -d >. 
V V ? Si, 

ScQ pa 




C 

2 



- 2« 

.2'S2 
>piO 




























U 




"o 
O 

"o 

a 




•d 

0) 


m 
'S 


■it 




c 

'a 


Pi o« 

•S .s.s 

§ --PPg 


S? oj "qj 


"3 
>. 

3 


.3 
c 


V- 3 C 
ta CD 






oj 


M 




w rt 


1° 


u 


'-'";!£>. >.'=' 




a 


^< 


N 1ht3 






z 




CJ 


V. 

PS t3 


J3 



X o^ CC^ 
OWmWWO, 


00 .y 
piW Pi > 


S 


3 
< 


'•S 3 3 






"c" 


M M 


N 


r<5 








0. N mot- 00 


M n N 


i^ 





'J-t^O 






►5« 


o> 





00 11 


« 




M M >->lH M 


NO N 




* 




t<1 « 






* H 




Tt 10 




« 


M mm 1/1IO lo 


U5 10 m 








■^t^* 






^ t 






* 








* 








* 






o 






♦ 
















* 




































• 



ARTIFICIAL FOOD COLORS. 



873 



o 

I— I 

H 
!= 

h-1 

o 

tn 

o 

< 
> 

o 

H 

> 

O 

w 
h-1 

P3 
I— I 
U 



O 

u 
o 
o 

H 
O 

< 

H 

a 





Dichlorhy- 

drin- Carbon 

Tetrachlorid 

from N/64 

C2H4O2 

Solution. 


: I, nearly 
all; I : J. 
half or 
more 


















" 












- 1 




i 


















her 
N/6 
OH 
tion. 


u 


















4J - nl m 


















.•s C 


















►4 


























•d 








Tt 


















Ether 

from N/6, 

HCl or 

C2H4O2 

Solution. 











►J 






iJ 




"o „ Tf 




^ 


^ 
















^lo^Kg 




l-i 

0! 

a 

01 

t-l 
ol 


a 














1 


AmylAlc 

Gasol 

(I : 

from N 

NaO 

Soluti 


.2 
13 


_4) 

B 








lU 

c 

2 






en 


j 





























-p 














C 


"3 -r _ 






0. 
u 

E 
en 












U HI 

> 


o 

a 
< 

> 


fVmylAlcoh 
Gasoline 

(I :i) 

from N/6 

C2H4O2 

Solution. 


_5j 


"3 

Xi 
u 


> 










0. 




p4 


"o ■* 






0. 






■6 -6 






_2 


AmylAlcoh 

Gasoline 

(I :i) 

from N/6 

HCl 

Solution. 




"a 






■Sft 






+3 








OJ 






oj a 






"■d 




.2 


u 

> 




13 
E 






ES 
t- 


•d 




0) lU 

> 




S 0] 






0! 






IS 










C 


>, 


^. 






i?-d^- 






OJ rf 


•t 




•^ 




•d 


V- +j 43 






< 




2=^ 




^=3 




0. 


















1 








"o 












^ I, 










"3 
>> 










. frorr 
tral 
htly 
. sol. 


13 

•n'B 


13 




e2 w 


ca 
2 










Extd 
neu 
slig 
alk 


S ft 


2" 
















-d Si 
















c & ^ g 




01 ^ 
M 


4J 4J 

"o "o 

> > 








4> 

s 


CQ Oi 


2 § 1 -sLl-sl 

m S >- P^m>P^u 






ffl 








0) 


ffl 






■* 








3 


■<t 




u 




m 


« 


« 




3 


a 3 




"o 




^ 2 


c 




0) 


13 


■g « H m3 






.2 tS 


a 


3 


^ -a 


Benzopurp 

Alizarin bl 

Thioflavin 

Rhodamin 
Methylene 
New blue 
Safranin 
Fuchsin 




0, 


> -0 


DO 


3 


oJ 




e 


E 'T^ 


bo 
J3 


0! 


c 
IP 


Methyl 
Congo 




z 


1 ^ 


BO 
Z, 


'5 










00 ■^ 


00 






*c 


t- « 00 vO 0. 'too 








^ 


ti -4 


t^ xO w 0.10 fOOO M- 




6 u 


<* 


t N 


M 10 -O TOxO >« •* 




^;s 


* 




* 






* 










































874 



FOOD INSPECTION AND ANALYSIS. 



O 

I 
m 

'^ 
O 
I— I 
H 

O 



in 
O 

< 
> 

o 

m 
> 

o 

oi 

w 
hJ 

P5 
I— I 
O 



P3 
m 

O 

o 
u 

o 
o 

I— I 
H 
U 

H 
X 







"3 






















6 « 
-0.2 


. 0) 0. 

2"*^ E 
2^^ o 


u 

ft 
u 










■3 
>> 

c 




u 

c 
"^ 
-\ 
Z 

z"^ 










Z 


z 








z 




Z 
















•<t 


■- 






















o 


'^ in 










fcE9i 












zs 
.. ft 












^ 2K'-3 












z-^ 
























"3 •* 
E:«1J 

"za 






















Z 










o 






















t (U L 


c; 






















-o > " 


o 






















•-"^ o S 


c 




















•d 




u 
O 




















u 




















1 


^s ^ 


+j 




















tj 




J 




















M 
























1 --^ 












>« 


I*-, 
































c 

3 
O 

< 


11 £^« 




4J 

U 

ft 
u 








c 








■3 


1 

c4 


4^ 


"3 
S 








1 


(U 

o 






13 

ol 
V 

Z 
















































Ci 


^ "^ 




« 












C8 








&•• t 


^ 


« 




4J 






.^ 


.c 








^•-EW-2 


1- 

ft 


c 

a, 

■a 
*-> 




ft 




iJ 


t- 

ft 






c3 
ft 
u 

ci 




E 


V 




'a 

E 




(U 


"3 
E 






<o 


M 


J 




w 




> 


w 




>-) 


























o 
























iiK o 














































^e'^ 














































Eiw 
























< 
















































"3 






















E 2 w 
























2 






















"^sj 
















•a 


•a 


•a -a 




-^s 


& & 


^ 


■*-> 


c 


C 


c c 


u V 

§£ U 


V 


V 


V V 




r=;^-i 


_o _o 


^ 


— 


& & 


c 5 


V 


V 


zi 




u tg 


"3 "S 


o 


"o 


u 


^ 


o 


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CHAPTER XVIII. 
FOOD PRESERVATIVES. 

Preservation of Food. — ^Various processes have from ancient times 
been known and used for arresting the fermentative changes which food 
products in their natural state undergo on long standing. These proc- 
esses include pickling with vinegar, drying, smoking, salting, preserving 
with sugar, and finally in the employment of heat in sterilizing and pas- 
teurizing, and of low temperature as in cold storage. All of them are 
still in use, and are universally regarded as unobjectionable. In addi- 
tion to these old and well-known methods of food preservation is the 
comparatively modem practice of arresting fermentation by the use of 
such antiseptic chemical agents as formaldehyde, beta-naphthol, boric, 
salicylic, benzoic, and sulphurous acids or salts of these acids, etc., in 
regard to the wholesomeness of which there is considerable difference 
of opinion. These substances depend for their efficiency on the more 
or less complete inhibition of bacterial growth. Nearly all exert a power- 
ful antiseptic influence, to such an extent that to accomplish their object 
only small quantities need be used in food. 

Apart from their toxic effects, a marked difference naturally exists 
between the employment of such substances as salt, sugar, and vinegar 
for food preservation, all of which are in themselves foods, and in the 
use of chemical agents that have no food value. The advocates of 
the use of chemical antiseptics claim that there are no authentic instances 
on record of injury from the use of such small quantities of these sub- 
stances as are necessary to arrest decay, while there are many cases of 
injury arising from the use of foods which, while apparently wholesome, 
have undergone such fermentation as to develop ptomaines or other 
harmful toxins, and that because antiseptics prevent such spoiling of the 
food, their use is decidedly beneficial ; that there is, besides, no more 
reason why a prejudice should exist against the employment of these 

876 



r 



FOOD PRESERVATIVES. 877 



newer chemicals than against saltpeter, which has long been used in the 
coming of meat, or against the cresols and phenols left as a product of 
smoking. 

The opponents to their use assert, that the addition to food of 
such antiseptic substances as prevent its decay also serves to retard 
the digestive processes when the food is eaten; that many of these 
substances are drugs, and as such cannot fail even in small quantities 
to exercise a toxic effect of some sort on the system; that finally their 
use is objectionable, as allowing the employment in certain foods of 
old materials that have in some cases already undergone incipient 
decomposition before the addition of the antiseptic, and are thus un- 
wholesome. 

Regulation of Antiseptics in Food.— In the absence of legislation 
directly prohibiting the use of any of the above-named antiseptics, and 
in view of the difference of opinion regarding their toxic effects when 
present in small quantities, it is difficult to maintain a complaint under 
the general food laws as they exist in most states, basing the complaint 
solely on their harmfulness. In some locaHties certain antiseptics are 
specifically allowed and others are prohibited. Some of the states, as, 
for example, Massachusetts, have special laws under which it is required 
that in the case of all foods thus treated, the name and percentage of such 
antiseptics as are used must appear plainly on labels of the packages 
or containers thereof, such a provision being based on the assumption 
that the general public should be informed of what they are buying, where 
any doubt exists as to the wholesomeness of any ingredient present. 
Where such laws as these arc in force, the chemist's task is compara- 
tively easy, in that conviction in court is not dependent on his individual 
opinion regarding the toxic effects of the antiseptic employed. 

Physiological experiments for testing the toxicity of these chemical 
preservatives were formerly confined to the lower animals, but no 
satisfactory results could be thus obtained. Later, metabolism experi- 
ments were made on human beings treated with varying amounts of the 
preservatives under carefully controlled conditions, but the results of 
these, though made by experts of unquestioned ability, do not agree. 
Even if any of these substances as used in food appear to have little or 
no effect on people in good health, they cannot be assumed to be equally 
harmless to those who are inchned to be dehcate or sickly. Even though 
pronounced harmless in themselves, there is still the objection that the 
chemical preservatives may readily conceal unclean methods or materials. 
If perishable foods are free from preservatives and are sweet and 



878 FOOD INSPECTION AND ANALYSIS. 

untainted, the consumer has reason to believe that clean and whole- 
some materials and sanitary processes were employed throughout in 
their manufacture. 

Commercial Food Preservatives. — A large number of commercial 
preparations are sold for purposes of preserving specific articles of food 
and are put out under trade names that usually convey no suggestion 
of their true character. Some of these consist of a single antiseptic sub- 
stance, such as salicylic acid, ammonium fluoride, calcium sulphate, 
borax, or benzoic acid, while others are mixtures of several antiseptics, 
of which the following are typical examples, showing their composition 
as found, together with the amount of the mixture to be employed. 

A. For preserving sausage meat, using 8 ounces per loc pounds 
of meat: 

Borax 36% 

Salt 46% 

Sakpeter 18% 

(Colored with an anilin dye.) 

B. For preserving cider and ketchup. 

A 34% solution of beta-naphthol in alcohol, using 2 fluid ounces U 
45 gallons of cider, or i^ ounces to i a gallons of ketchup. 

C. For preserving beer, using i^ ounces per barrel of beer: 

Salt 45% 

Salicylic acid 27% 

Sodium carbonate and salicylate 28% 

D. For preserving chopped meats, using i ounce to 50 pounds oi 
meat* 

Sodium sulphite 65% 

Borax 35% 

E. Effective for curing beef, hams, tongues, bacon, pig's feet, 
etc.: 

Borax 28% 

Boric acid 12% 

Sodium chloride 35% 

Potassium nitrate 25% 

F. For preserving milk and cream: 

Boric acid 75% 

Borax 25% 



FOOD PRESERVATIVES. 879 

G. For preserving jellies, jams, preserves, mince-meat, and syrups, 
using from i to 2 ounces of preservative to 100 pounds of product: 

Sodium benzoate 50% 

Boric acid 40% 

Sodium chloride 5% 

Sodium bicarbonate. . 5% 

H. For p-eserving ketchup and tomato pulp, using from 6 tc 
8 ounces to 45 gallons of the product : 

Sodium benzoate 50% 

Sodium chloride 40% 

Sodium sulphite 10% 

/. Effective for keeping butter from becoming tainted or rancid, 
also for salt codfish, using 8 to 12 ounces per 100 pounds butter: 

Boric acid 25% 

Borax 50% 

Sodium chloride 25% 

/. For preserving eggs (surface application). A saturated solu- 
tion of salicylic acid in 3 quarts of water, 1 quart strong alcohol and 7 
ounces of glycerin. 

FORMALDEHYDE. 

Formaldehyde (HCHO) is a gas formed by the action of a red-hot 
spiral of platinum wire on vaporized methyl alcohol. It is also produced 
by the dry distillation of calcium formate. In the market it commonly 
appears in the form of a 40% solution of the gas in water under the name 
of formalin, and for use as a food preservative dilute solutions of from 
2% to 5% strength are usually employed. Its use as a food preservative 
is comparatively modern. 

The prompt and direct action of formaldehyde in checking or preventing 
the growth of lactic acid bacteria renders it especially desirable for use as a 
milk and cream preservative, from the standpoint of the dairyman who does 
not concern himself as to whether or not its use is injurious or illegal. 
The common proportion of i part of formaldehyde to 20,000 parts of milk 
will keep milk sweet for four days in Summer weather. 

Small amounts of formaldehyde occur naturally in certain foods. For 



880 FOOD INSPECTION AND ANALYSIS. 

example, Kawahata and Namba * have detected it in smoked meats 
and Ishida f in crab meat, especially in preserved crab meat kept several 
months. 

Determination of Formaldehyde in the Commercial Preservative. — 
(i) lodometric Method. X — Mix lo cc. of the aldehyde solution (diluted 
if necessary to a strength not exceeding 3% of formaldehyde) with 25 cc. 
of tenth-normal iodine solution, and add drop by drop a solution of sodium 
hydroxide, till the color of the liquid becomes clear yellow. The solution 
is set aside for at least ten minutes, after which hydrochloric acid is added 
to set free the uncombined iodine, and the latter is titrated back with 
tenth-normal thiosulphate. Two atoms of iodine are equivalent to one 
molecule of formaldehyde, in accordance with the following reactions: 

6NaOH +61 =NaI03 +5NaI +3H2O. 

3CH2O +NaI03 =3CH202 +NaI. 

5NaI+NaI03+6HCl = 6NaCl+l6+3H20. 

(2) Method of Blank and FinkenheinerA — Three grams of the solu- 
tion are weighed into a tall Erlenmeyer flask, to which is then added 
from 25 to 30 cc. of twice-normal sodium hydroxide. Fifty cc. of pure 
2.5% to 3% hydrogen peroxide solution are next gradually run in during 
a space of from three to ten minutes, through a funnel placed in the neck 
of the flask to prevent spurting, and the solution is allowed to stand for 
two or three minutes, after which the funnel is washed with water. 

Finally the unused sodium hydroxide is titrated with twice-normal 
sulphuric acid, using litmus as an indicator. The less formaldehyde 
in the sample, the longer the mixture should stand after addition of the 
hydrogen peroxide, to complete the reaction. When less than 30% is 
present, it should stand at least ten minutes. 

Ascertain the percentage of formaldehyde, by multiplying by 2 the 
number of cubic centimeters of soda solution used, when 3 grams of the 
sample are taken. 

(3) Ammonia Method.\\ — Weigh 10 grams of the formaldehyde solu- 
tion into a flask, and treat with an excess of ammonia. Cork the flask 

* Jour. Pharm. Soc, Japan, 432, 1918, p. 95. 

t Ibid., 422, 1917, p. 300. 

t Zeits. anal. Chem., 1897, 36, pp. 18-24. 

§Ber., 31 (17), 297Q. 

II Conn. E,\p. Sta., Annual Report, 1899, P- 143- 



FOOD PRESERVATIVES. 881 

and shake frequently during several days. The formaldehyde is by this 
process converted into hexamethylamine. 

Transfer the solution to a tared platinum dish, and evaporate nearly 
to dryness on the top of a closed water-bath. Finally the dish is trans- 
ferred to a desiccator, and the drying continued over sulphuric acid to 
constant weight. The per cent of formaldehyde is calculated from the 
weight of the hexamethylamine, making a correction for the residue left 
by the formaldehyde itself by direct evaporation : 

6CH2O +4NH4OH = (CH2)6N4 + 10H2O. 

Or an excess of a standardized ammonia solution may be added in 
the first place, the excess of ammonia being distilled off and titrated with 
standard acid, calculating the per cent of formaldehyde by the amount 
of ammonia absorbed. 

Detection of Formaldehyde.— Methods have previously been given 
for the detection of formaldehyde in milk. For other materials acidify a 
portion of the sample with phosphoric, sulphuric, or citric acid, subject 
to distillation, and test the first few cubic centimeters of the distillate 
as follows: 

Leach Test. — Add a few drops of the suspected distillate to about 10 cc. 
of pure milk (previously proved free from formaldehyde) in a porcelain 
casserole, and carry out the test as described on page 165. 

Hehner Test. — Apply the test as described on page 165 to 10 cc. of pure 
milk to which a few drops of the suspected distillate have been added. 

Rimini Test.^— Mix 20 cc. of the distillate with i cc. of phenylhydrazine 
hydrochloride solution (4 : 100) and 4 drops of freshly prepared sodium 
nitroprusside solution (i : 200) and finally add concentrated sodium 
hydroxide solution drop by drop to the mixture. Formaldehyde is indicated 
by the appearance of a blue or, in dilute solutions, a green coloration which 
changes to red on standing. When formaldehyde is absent, only the red 
color appears. 

Arnold and Mentzel'\ shake 5 grams of meat or melted fat with 
10 cc. of alcohol, or 10 cc. each of milk and alcohol, and filter, then add 
to 5 cc. of the filtrate 0.03 gram phenylhydrazine hydrochloride, 4 to 5 
drops of 1% ferric chloride solution, and, with agitation in a bath of cold 



* Anal, farm., 1898, p. 97. 

t Zeits. Unters. Nahr. Genussm., 5, 1902, p. 353. 



882 FOOD INSPECTION AND ANALYSIS. 

water, lo to 12 drops of concentrated sulphuric acid. A red color indicates 
formaldehyde. 

Barbier and Jandrier Test* — According to Williams and Sherman f 
this test is especially trustworthy. Mix 5 cc. of the distillate with 0.2 to 
0.3 cc. of a saturated alcoholic solution of gallic acid and pour the mixture 
into 3 to 5 cc. concentrated sulphuric acid in a test-tube. A green zone 
slowly changing to blue at the juncture of the liquids indicates formalde- 
hyde. 

Lebbin Test. — To about 10 cc. of the distillate to be tested, add a few 
drops of a 1% solution of resorcinol, mix thoroughly, and carefully pour 
the liquid down the side of a test-tube containing concentrated sulphuric 
acid. In the presence of formaldehyde, a rose-red zone is formed at the 
junction of the two liquids, sensitive to i part in 200,000. If formaldehyde 
be present to an extent exceeding i part in 100,000, a white turbity or pre- 
cipitate is formed above the colored zone. 

SchiJl's Reagent (one gram of fuchsin dissolved in water, 20 cc. 
saturated sodium hydrogen sulphite solution, and 10 cc. concentrated hydro- 
chloric acid, made up to i liter) gives a pink coloration when a drop is added 
to a few drops of the distillate containing any aldehyde and is therefore a 
group reaction and not characteristic of formaldehyde. 

Fincke | states that employing the Grosse-Bohle reagent (25 grams crys- 
tallized sodium sulphite dissolved in a solution of i gram of rosanilin 
hydrochloride or acetate in 500 cc, of water, treated with 15 cc. 25% 
hydrochloric acid, diluted to i liter, and allowed to stand several hours) 
a test is obtained with which ordinary amounts of other aldehydes do not 
interfere, although hexamethylenetetramine reacts in a similar manner. 
He proceeds as follows: Mix 10 cc. of the solution to be tested with i to 2 cc. 
of 25% hydrochloric acid and decolorize by shaking or warming with puri- 
fied animal charcoal or with the addition of mercuric chloride in the case 
of meat products or mercuric acetate in the case of fruit products. Filter 
and shake the filtrate with i cc. of the reagent. The blue or blue-violet 
color indicative of formaldehyde should appear within twelve hours. 

To detect hexamethylenetetramine, heat the solution to be tested, after 
mixing with the hydrochloric acid, in a water-bath for ten minutes, cool, 
and then add the reagent or else test the distillate obtained in the usual 
manner. 

* Ann. chim. anal, app., i, 1896, p. 325. 

t Jour. Amer. Chem. Soc, 27, 1905, p. 1497. 

X Zeits. Unters. Nahr. Genussm., 27, 1914, p. 246. 



4 



FOOD PRESERVATIVES. 883 

Quantitative Determination of Formaldehyde, especially in the case 
of milk (page 165) and other products containing proteins, is unsatisfac- 
tory. Results by the following method should therefore be reported as 
recoverable formaldehyde. 

Romijn Method.* — Treat 10 cc. of tenth-normal silver nitrate with 6 
drops of 50% nitric acid in a 50-cc. flask, add 10 cc. of a solution of potas- 
sium cyanide containing 3.1 grams of KCN in 500 cc. of water, and make 
up to the 50-cc. mark. Shake, filter, and titrate 25 cc. of the filtrate with 
tenth-normal ammonium sulphocyanate, using ferric chloride as an indicator. 

Acidify another portion of 10 cc. of tenth-normal silver nitrate with 
nitric acid, add 10 cc. of the potassium cyanide solution to which the 
above 20 cc. of the formaldehyde distillate has been added. Make up 
the whole to 50 cc, filter and titrate as before — 25 cc. of the filtrate with 
tenth-normal ammonium sulphocyanate for the excess of silver. 

The amount of potassium cyanide used up by the formaldehyde, in 
terms of tenth-normal ammonium sulphocyanate, is found by multiplying 
by 2 the difference between the two results, and the total formaldehyde 
is calculated by multiplying by 3 the amount found in the 20 cc. of 
distillate. 

The reaction that takes place between the formaldehyde and the 
potassium cyanide probably results in the formation of an addition product 
as follows: 

CH20-hKCN = KO.CH2CN. 

BORIC ACID. 

Boric or boracic acid is commonly obtained in impure form from 
lagoons or fumaroles of volcanic origin in Tuscany. It is afterwards 
purified by recrystallization. It is weakly acid, and readily soluble in 
water and in alcohol. Its alcoholic solution, even when the acid is present 
in small quantity, burns with a characteristic green flame. The acid 
is quite volatile with steam. 

Borax, the most commonly known salt of boric acid, is found native 
in Italy, California, and elsewhere, and is also made from boric acid. It 
is mildly alkaline, and readily soluble in water. 

Boric acid and borax, either used separately or mixed, have long been 
used as preservatives, especially in animal foods. A mixture of 3 parts 

* Zeits. anal. Chem., 36, 1897, p. 18. 



884 



FOOD INSPECTION AND ANALYSIS. 



boric acid and i part borax has been found very effective as a milk and 
butter preservative, as well as for meat products. It also has been used in 
fruit products, wines, beer, and temperance beverages. 

Boric acid is quite widely distributed in nature. In small amounts it 
is a normal constituent of fruits including the grape, and consequently 
wines. It occurs in minute quantities in vegetables, meat, fish, eggs, and 
even milk. Mediterranean Sea water, according to Bertrand and Agulhon,* 
contains 56.3 mg. of boric acid per liter. The amounts naturally present 
in foods are ordinarily too small to give decisive reactions with the turmeric 
tests employing the usual quantities. 

Determination of Boric Anhydride in Commercial Preservatives. — 
Gladding Method.^ — A 150-cc. flask, Fig. 117, is arranged with a doubly 




Fig. 117. — Apparatus for Determining Boric Acid According to Gladding. 

perforated stopper having two tubes, one of which, the inlet-tube reach- 
ing nearly to the bottom, connects it with a larger flask, while the other 
or outlet-tube communicates with a Liebig condenser, which in turn 
delivers into a receiving-flask. In the 150-cc. flask, i gram of the powdered 
sample is placed, with about 20 cc. of 95% methyl alcohol and 5 cc. of 85% 
phosphoric acid. The larger flask is then filled two-thirds full of methyl 
alcohol, and heated on the water-bath after the apparatus has been con- 



* Bol. soc. chim., 15, 1914, p. 292. 

t Jour. Amer. Chem. Soc, 20, 1898, p. 288. 



FOOD PRESERVATIVES. 885 

nected up. Heat is also applied to the 150-cc. flask, the whole arrangement 
being such that a continuous current of methyl alcohol vapor bubbles 
through the liquid in the smaller flask, the heat being so regulated that from 
15 to 25 cc. of methyl alcohol remains in the 150-cc. flask, while about 
100 cc. of distillate passes into the receiving-flask in half an hour. Con- 
tinue the distillation till all the acid has passed over, which is usually 
accomplished by distilling 100 cc. By a gentle aspu-ation upon the 
receiving-flask, loss by leaking may be avoided. 

Prepare a mixture of 40 cc. of glycerin and 100 cc. of water, and care- 
fully neutralize, using phenolphthalein as an indicator. Add this mixture 
to the distillate, and titrate the whole with tenth-normal sodium hydroxide. 
Run a blank with the reagents alone, deducting any acidity. For the fac- 
tors for calculation see page 887. ! 

Detection of Boric Acid and Borates. — These are tested for in the 
aqueous extract of the material itself or of the ash, the quantity to be used 
for the test depending largely on the case in hand. With meat products 
and canned goods, about 25 grams are either boiled up with water or first 
made distinctly alkaline with lime water, dried over the water-bath, and 
burned. The ash is boiled with from 10 to 15 cc. of water, and tests 
made on the solution. With such products as salt codfish, which is 
preserved by brushing or coating with boric mixture, portions of the 
coating may be scraped off and boiled in water, the tests being made 
on the aqueous solutions. 

The Turmeric-paper Tg^/.— The most delicate test for boric acid, 
free or combined, is made by the aid of turmeric-paper, prepared by soak- 
ing a smooth, thin grade of filter-paper in an alcoholic tincture of pow- 
dered turmeric. The paper is afterwards dried and cut into strips, which 
are kept for convenience in a wide-mouthed bottle in a dark place. 

Acidulate the aqueous extract of the material or the ash with con- 
centrated hydrochloric acid, equivalent to about 5 drops per 10 cc. in 
excess of what is necessary for neutralization. Then dissolve the ash in a 
few drops of water and thoroughly saturate a strip of the turmeric-paper 
in the solution. On drying the paper, if boric acid either free or combined 
be present, a cherry-red coloration will be imparted to the paper, the 
depth of color depending on the amount present. As a confirmatory test, 
apply a drop of dilute alkali to the reddened paper, and a dark-olive color 
will be due to boric acid, sharply to be distinguished from the deep-red 
color produced when an alkaline solution is applied to ordinary turmeric- 
paper. The turmeric-paper reaction is delicate to i part in 8000. 



886 FOOD INSPECTION AND ANALYSIS." 

Tincture of Turmeric Test.— To the solution to be tested, slightly 
acidified with hydrochloric acid, add an equal volume of saturated tinc- 
ture of turmeric in an evaporating-dish, and heat for a minute or two. A 
red color, light or dark, depending on the amount of the preservative, 
is produced if boric acid be present, changed to an olive color by the addi- 
tion of dilute alkali, after cooling. 

The Flame Test. — A few cubic centimeters of alcohol are added to 
the dish containing the slightly acidulated ash of the sample to be tested, or 
to the acidulated dried residue from the evaporation of the aqueous solution 
of the suspected preservative, and after mixing by the aid of a stirring- 
rod, the alcohol is ignited. In the presence of any considerable portion 
of free or combined boric acid, a greenish tinge will be observed in 
the flame of the burnmg alcohol, especially at the first flash due to 
the boric ether formed. This test is by no means as delicate as the 
turmeric paper test. 

Determination of Boric Acid in Foods. — Thompson Method.^ — Add 
I or 2 grams of sodium hydroxide to loo grams of the sample, and evapo- 
rate to dryness in a platinum dish. Char the residue thoroughly, and 
boil with 20 cc. of water, adding hydrochloric acid drop by drop till all but 
the carbon is dissolved. In burning, avoid too high a heat, simply charring 
sufficiently to insure a clear solution with water. Transfer by washing 
to a loo-cc. graduated flask, taking care that the volume does not exceed 
50 or 60 cc. Add half a gram of dry calcium chloride, then a few drops 
of phenolphthalein solution, and next a 10% solution of sodium hydroxide, 
till a permanent pink color persists. Finally add 25 cc. of lime-water. 
By this means all phosphoric acid is precipitated in the form of calcium 
phosphate. Make up to the loo-cc. mark with water, shake, and pour 
upon a dry filter. To 50 cc. of the filtrate add sufficient normal sulphuric 
acid to remove the pink color. Then add a few drops of methyl orange, 
and continue the addition of sulphuric acid till the yellow is just turned 
to pink. Tenth-normal sodium hydroxide is then added f till the liquid 
takes on a faint yellow, excess of alkali being avoided. The salts of the 
acids present at this time are all neutral to phenolphthalein except boric 
acid and carbon dioxide. Boil the solution to expel the carbon dioxide, 
cool, add a little more phenolphthalein, and a quantity of glycerin equal 

* Jour. Soc. Chem. Ind., 12, 1893, p. 432. 

t If the value of the standard alkali solution is not absolutely certain, it had best be 
restandardized against pure crystallized boric acid, 0.31 gram of which should neutralize 
50 cc. of tenth-normal alkali. 



FOOD PRESERVATIVES. 887 

in volume to the solution. Finally titrate with tenth-normal sodium 
hydroxide to a permanent pink color. Each cubic centimeter of tenth- 
normal sodium hydroxide equals 0.0062 gram crystallized boric acid, 
H3BO3, or 0.0035 gram boric anhydride, B2O3, or 0.00955 gram crystal- 
lized borax, Na2B407,ioH20. 

Gooch Method.— Mix 400 to 500 grams of the substance with 10 grams 
of calcium hydrate, evaporate to dryness over a water-bath in a platinum 
dish and burn cautiously to an ash. Dissolve the residue in cold nitric 
acid, and add an excess of silver nitrate to precipitate the chlorine. Filter, 
make up to 500 cc. with water, shake, and measure out 25 cc. into a 
200-cc. flask fitted with a stopper provided with an outlet-tube, and with 
a separatory funnel forming virtuaMy a thistle-tube, capable of being 
closed with a glass stop-cock. Through the outlet-tube connect the flask 
with a Liebig condenser provided with an adapter which can dip below 
the liquid in the receiver. As a receiver, use a 150-cc. tared platinum dish, 
which contains a weighed quantity of ignited lime in water. 

Add through the thistle-tube 10 cc. of methyl alcohol to the contents 
of the flask, close the stop-cock therein, and distil the contents in a paraffin- 
bath at a temperature of 140° C, constantly stirring the liquid in the 
receiver to keep it alkaline during the distillation. Add five successive 
portions of methyl alcohol of 12 cc. each to the distilling flask, and con- 
tinue the distillation till all the alcohol has passed over. Finally evaporate 
to dryness the contents of the platinum dish, and ignite over a blast-lamp 
to constant weight. Multiply the increased weight due to boric oxide by 
2.728 to give the equivalent in borax. 

SALICYLIC ACID. 

Salicylic acid (HC7H5O3) is a white, crystalline, strongly acid powder, 
made synthetically by treatment of carbolic acid with sodium hydroxide 
and carbon dioxide, or naturally from methyl salicylate (which occurs in 
oil of wintergreen to the extent of about 90%) by treatment of the winter- 
green oil with strong potash lye. Most of the commercial salicylic acid is 
of the synthetic variety. Pure salicylic acid crystallizes from alcoholic 
solutions in 4-sided prisms, and from aqueous solution in long, slender 
needles. It melts at 155° to 156° C. It is slightly soluble in cold water 
(i part in 450), and much more so in hot water. It is readily soluble in 
ether, alcohol, and chloroform. 

It is frequently found on the market as a food preservative in the form 



888 FOOD INSPECTION AND ANALYSIS. 

of the much more soluble sodium salt, sodium salicylate (NaCTHsOs), 
which is, however, converted into salicylic acid when added to acid-fruit 
preparations, condiments, and liquors. 

Sodium salicylate is a white, amorphous powder, soluble in 0.9 part 
water and in 6 parts alcohol. It is prepared by treating salicylic acid 
with a strong, aqueous solution of sodium carbonate, and afterwards 
purifying. If a known weight of the powdered preservative be ignited, 
and a solution of the ash titrated with tenth-normal sulphuric acid, using 
cochineal as an indicator, each cubic centimeter of the acid is equivalent 
to 0.0160 gram of sodium salicylate. 

Salicylic acid is largely used as a preservative of jellies, jams, and 
fruit preparations, canned vegetables, ketchups, table sauces, wines, 
beer, and cider. It is rarely used in milk and milk products, or in meats. 

Bucholz has shown that 0.15% of salicylic acid is sufficient to prevent 
bacteria from developing in ordinary organic substances, while as small 
a quantity as 0.04% produces a marked restraining influence. 

Small amounts of salicylic acid occur naturally in grapes, strawberries, 
and other fruits, but the amounts are too small to give distinct color reac- 
tions when only 50 grams of the fruit products are used for tests. 

Detection of Salicylic Acid. — If the sample to be tested is of a similar 
nature to jelly, jam, ketchup, cider, etc., or capable of getting into aque- 
ous solution, slightly acidify the liquid or pasty material, diluted, if neces- 
sary, with weak sulphuric (if not already acid) and shake directly with 
an equal bulk of ether, petroleum ether, or chloroform, in a corked flask, 
or in a separatory funnel. If the sample be too thick in consistency to 
shake directly, macerate in a mortar with alkaline water, and strain through 
cloth. Acidify the filtrate with dilute sulphuric acid, and then proceed 
to shake with the immiscible solvent as above. Separate by decantation or 
otherwise the immiscible solvent containing the preservative, if present, and 
allow it to evaporate in an open shallow dish, either at room temperature 
or at a low heat. In case an emulsion forms on shaking, which is quite 
apt to happen, especially with ether for a solvent, divide the whole mixture 
between two tubes of a centrifuge of the form shown in Fig. 1 1 , and whirl 
for three minutes at a high rate of speed. This usually serves to break 
up the most obstinate emulsion, so that it is easy to separate by decanta- 
tion. If a considerable amount of salicylic acid be present, it will sometimes 
appear in the residue in the form of fibrous crystals. 

Ferric Chloride Test. — To a portion of the dry residue obtained as above 
add a drop of ferric chloride solution. A deep purple or violet color indi- 



FOOD PRESERVATIVES. 889 

cates salicylic acid. If doubt exists as to the color, dilute with water, which 
often serves to bring out a distinctive purple coloration otherwise unob- 
servable. 

Leach, instead of evaporating the ether solution of the salicylic acid 
to dryness, prefers to shake out the salicylic acid from the ether with dilute 
ammonia, evaporate the solution of ammonium salicylate nearly to dryness, 
and apply the tests given above to the concentrated solution. In this case 
the ether may be recovered, 

Maltol (CeHeOs), occurring in caramelized products or products 
containing caramel, such as dark beer, also other substances named by 
Sherman and Gross,* give a similar violet color, but the following test, 
recommended by Sherman f and Sherman and Gross, is characteristic 
only of salicylic acid. 

Jorissen Test.X — Add to the solution, obtained as above, in a test-tube 
4 to 5 drops of io% sodium or potassium nitrite, 4 to 5 drops of 50% 
acetic acid, and i drop of 1% copper sulphate solution, shaking after adding 
each reagent. 

Heat in a boiling water-bath with liquid completely immersed for forty- 
five minutes, cool, and compare the red color indicative of salicylic acid 
with a blank test against a white backgi'ound. Both Allen and Sherman 
and Gross have shown that benzoic, cinnamic, and tartaric acids do not 
respond to the test. 

Schott, § in the examination of milk, first removes interfering substances 
by adding to 25 cc. of the sample 10 cc. of Fehling copper sulphate solution 
and then sodium hydroxide solution until only faintly acid, and filtering. 

Methyl Salicylate Test. — Another portion of the residue may be heated 
with methyl alcohol and sulphuric acid. If salicylic acid be present, the 
well-known odor of methyl salicylate will be produced. 

Ammonium Pier ate Test. — A portion of the dry ether extract is warmed 
gently with a drop of concentrated nitric acid, and 2 or 3 drops of ammonia 
are added. Yellow ammonium picrate will be formed if a considerable 
quantity of salicylic acid be present, and a thread of wool free from fat may 
be dyed by soaking therein. This test is by no means as delicate as the 
ferric chloride color test. 



* Jour. Ind. Eng. Chem.j 3, 191 1, p. 492. 

t Ibid., 2, 1910, p. 24. 

X Bui. acad. roy. sci. let. beauxa. Belg. [3] 3, 1882, p. 259. 

§ Zeits. Unters. Nahr. Genussm., 22, 1911, p. 727. 



890 FOOD INSPECTION AND ANALYSIS. 

Determination of Salicylic Acid. — Dubois Method.'^ — In the case of 
catsups and similar pulped materials place 50 grams in a graduated 
200-cc. flask, make slightly alkaline with ammonia, add 15 cc. of milk 
of lime (200 grams of quicklime in 2000 cc. water), complete the volume, 
shake and filter. Transfer 150 cc. of the filtrate to a separatory funnel, 
acidify with hydrochloric acid, and extract with four portions of 75 to 
100 cc. of ether. Wash the combined extract twice with 25 cc. of water, 
and distil off the ether slowly, allowing the last 20 to 25 cc. to evaporate 
spontaneously. Dissolve the residue in a small amount of hot water, 
make up to a definite volume with water, and add to an aliquot portion 
a few drops of a 2% solution of ferric alum to develop the color. Esti- 
mate the amount of salicylic acid by matching the color thus obtained 
with that produced in a solution containing i mg. of salicylic in 50 cc, 
using either a colorimeter or Ncssler tubes for making the comparison. 

In the case of semi-solid materials, such as mince meat, jams, etc., 
macerate 50 grams with water in a mortar previous to treatment as above 
described. 

Liquids and solutions of jellies and other materials free from pulp 
may be extracted with ether directly after acidifying. 

BENZOIC ACID. 

Benzoic Acid (HC7H5O2) is produced by the oxidation of a large 
number of organic substances, particularly toluene. It is also extracted 
by sublimation from gum benzoin, which exudes from the bark of the 
Styrax benzoin, a tree growing in Java, Sumatra, Borneo, and Siam. 
Most of the commercial benzoic acid is made from toluene by treatment 
with chlorine and subsequent oxidation. 

Benzoic acid crystallizes in leaflets, having a silky luster. It is odor- 
less when cold, is soluble in 200 parts of cold, and 25 parts of boiling 
water, and readily dissolves in alcohol, ether, and chloroform. Its melt- 
ing-point is 120°, and it sublimes at a slightly higher temperature. It 
occurs naturally in the cranberry and other berries of the EricacecB. 

Sodium Benzoate (NaC7H502) is the salt most largely used in commer- 
cial preservatives, being much more soluble than the acid itself, into 
which, however, it is converted when put into acid fruit preparations. 
Sodium benzoate is prepared by adding benzoic acid to a concentrated 

* Jour. Amer. Chem. Soc, 28, 1916, p. 1616. 



FOOD PRESERVATIVES. 891 

hot solution of sodium carbonate till there is no longer effervescence, 
and then cooling, and allowing the sodium benzoate to crystallize out. 
In titrating solutions of ignited sodium benzoate with tenth-normal sul- 
phuric acid, each cubic centimeter of the standard acid is equivalent to 
0.0144 gram of the benzoate. 

Sodium benzoate is a white amorphous powder, having a sweetish, 
astringent taste, and is soluble in 1.8 parts of cold water, and in 45 parts 
of alcohol. It is used as a preservative of catsups, fruit products, soft 
drinks, wines, codfish, nut butter, and similar products. In England it 
is used in milk. 

Long, Herter, and Chittenden of the Referee Board of Consulting 
Scientific Experts, after independent experiments, conclude that sodium 
benzoate in small doses (less than 0.5 gram per day) is not injurious to 
health and in large doses (up to 4 grams per day) has not been found to 
exert any deleterious effects on the general health nor to act as a poison 
in the general acceptance of the term. Accordingly this preservative is 
allowed under the federal law provided the presence and amount are 
declared on the label.* 

Many manufacturers do not use benzoate in any of their products, 
thus avoiding the obnoxious declaration of its presence or justifying a 
declaration of its absence. 

Detection of Benzoic Acid.— Extract with ether or chloroform as 
directed for salicylic acid. If it is desired to test for both preservatives 
divide the extract into two parts and evaporate in separate dishes. A 
considerable amount of benzoic acid is apparent in the residue as shining 
crystalline scales or needles. 

In the author's experience a better procedure than evaporating the 
ether solution is to extract the benzoic acid from the ether by shaking 
with dilute ammonia, evaporate the solution of ammonium benzoate nearly 
to dryness, and apply tests to the concentrated solution. 

(i) Ferric Chloride Test.— A portion of the residue from the ether 
extract is dissolved in ammonia, and evaporated over the water-bath until 
neutral to test paper. The residue is stirred in a few drops of warm water, 
and filtered through a small filter into a narrow test-tube. A drop of 
neutral ferric chloride (prepared by precipitating a portion of the iron 
from a solution of the salt by ammonia and filtering) is added, and in 
the presence of benzoic acid a flesh-colored precipitate of ferric benzoate 



Food Inspection Decision, 104. 



892 FOOD INSPECTION AND ANALYSIS. 

is produced, very characteristic and unmistakable, because of its peculiar 
color, when the solution in which the test is made is colorless. It occasion- 
ally happens, however, in the case of jellies, jams, and ketchups, that 
these preparations are artificially colored with a dyestuff that persists by 
its depth of color in obscuring that of the ferric benzoate, especially when 
only a small amount of benzoic acid is present. Again, in such products 
as sweet pickles, a precipitate of basic ferric acetate might also come 
down with the ferric benzoate, and thus confuse. In such cases one of the 
following methods should be carried out. 

(2) Sublimation Method."^ — Evaporate an ammoniacal solution of the 
ether extract till neutral m a large watch-glass, by the aid of a gentle 
heat. Fasten with clips or otherwise a second watch-glass to the first, 
edge to edge, so as to form a double convex chamber, with a cut filter- 
paper between. Place upon a small sand-bath and heat. Benzoic acid, 
if present, will sublime upon the surface of the upper glass in minute 
needles, recognizable under the microscope. It may further be tested 
by determining the melting-point, or by treating with ammonia, evapo- 
rating, and applying the ferric chloride test as above. 

(3) Mohler Method Modified hy Heide and Jakoh.'\ — Evaporate the 
ether extract to dryness, take up the residue in i to 3 cc. of third-normal 
sodium hydroxide, and evaporate to dryness. To the residue add 5 to 
10 drops of concentrated sulphuric acid and a small crystal of potassium 
nitrate. Heat for ten minutes in a glycerol bath at 120° to 130° C. (never 
higher), or for twenty minutes in a boiling water-bath, thus forming meta- 
di-nitro benzoic acid. After cooling add i cc. of water and make decidedly 
ammoniacal; boil the solution, to break up any ammonium nitrite which 
may have been formed. Cool and add a drop of fresh colorless ammonium 
sulphide, without allowing the layers to mix. A red-brown ring (ammo- 
nium meta-di-amido benzoic acid) indicates benzoic acid. On mixing, 
the color diffuses through the whole liquid; on heating it finally changes 
to greenish yellow, owing to the decomposition of the amido acid, thus dis- 
tinguishing benzoic from salicylic or cinnamic acids. Both the latter 
form amidp compounds, which are not destroyed by heating. The presence 
of phenolphthalein interferes with this test. 

(4) Peter Oxidation Method.X — This method, depending on the for- 



* Annual Report, Mass. State Board of Health, 1902, p. 

t Zeits. Unters. Nahr. Genussm., ig, 1910, p. 137. 

X U. S. Dept. of Agric, Bur. of Chem., Bui 65, p. 160. 



FOOD PRESERVATIVES. 893 

mation of salicylic acid, is not applicable in the presence of this acid or 
saccharin, which also oxidizes to salicylic acid. 

Transfer a portion of the residue, say o. i gram, from the ether or chloro- 
form extraction to a large test-tube, and dissolve in from 5 to 8 cc. of con- 
centrated sulphuric acid. Add from 0,5 to 0.8 gram of barium peroxide 
in successive small portions, shaking the tube in cold water. This should 
produce a permanent froth on the sulphuric acid solution. After stand- 
ing for half an hour, fill the test-tube three-quarters full of water, shake, 
cool quickly, and filter. Extract the filtrate with ether or chloroform, and 
test the extract for salicylic acid. 

The Jonescu test * is a modification of the Peter method employing 
hydrogen peroxide. Peter in his original process used this reagent. 

Determination of Benzoic Acid. — La Wall and Bradshaw Method. — 
Modified. — This process is based on principles brought to notice by 
Moerck.f Although originally devised for catsup, J it has been modified 
by Bigelow § and Dunbar || so as to be applicable to various classes of 
foods. The details which follow are those elaborated by Dunbar and 
adopted by the A. O. A. C. 

I. Preparation of Solution. — (a) General. — Grind in a sausage-machine, 
if solid or semi-solid, and thoroughly mix. Transfer about 150 grams to 
a 500-cc. flask, add enough pulverized sodium chloride to saturate the 
water in the sample, make alkaline with sodium hydroxide or milk of 
lime, and dilute to the mark with saturated salt solution. Allow to stand 
at least two hours with frequent shaking and filter. If the sample contains 
large arpounts of matter precipitable by salt solution follow a method 
similar to that given under {e) ; if large amounts of fats are present it is 
well to make an alkaline extraction of the filtrate before proceeding as 
directed under " Extraction and Titration." 

{b) Catsup. — To 150 grams of the sample add 15 grams of pulverized 
sodium chloride. Transfer the mixture to a 500-cc. graduated flask, 
using about 150 cc. of saturated salt solution for rinsing. Make slightly 
alkaline to litmus paper with strong sodium hydroxide and complete the 
dilution to 500 cc. with saturated salt solution. Allow to stand at least 
two hours with frequent shaking and then filter through a large folded 

* Jour, pharm. chim. [6], 29, 1909, p. 523. 

t Penn. Pharm. Assn. Proc, 1905, p. 181. 

% Amer. Jour. Pharm., 80, 1908, p. 171. 

§ U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 68. 

II Ibid., 1909, Bui. 132, p. 138; Circ. 66, p. 14 



894 FOOD INSPECTION AND ANALYSIS. 

filter. If difficulty is experienced, centrifuge or squeeze the mixture through 
a muslin bag before filtering. 

(c) Jellies, Jams, Preserves, and Marmalades. — Dissolve 150 grams of 
the sample in about 300 cc. of saturated salt solution. Add 15 grams of 
pulverized sodium chloride. Make alkaline to litmus-paper with milk 
of lime. Transfer to a 500-cc. graduated flask, and dilute to the mark with 
saturated salt solution. Allow to stand at least two hours with frequent 
shaking, centrifuge, if necessary, and filter through a large folded filter. 

(d) Cider and Similar Products Containing Alcohol. — Make 250 cc. of 
the sample alkaline to litmus-paper with sodium hydroxide and evaporate 
on the steam-bath to about 100 cc. Transfer to a 250-cc. flask, add 
30 grams of pulverized sodium chloride and shake until dissolved. Dilute 
to the mark with saturated salt solution, allow to stand at least two hours 
with frequent shaking, and filter through a folded filter. 

(e) Salt or Dried Fish. — Transfer 50 grams of the ground sample to a 
500-cc. flask with water. Make slightly alkaline to litmus-paper with 
strong sodium hydroxide and dilute to the mark with water. AFfow to 
stand at least two hours with frequent shaking and filter through a folded 
filter. Pipette at least 300 cc. of the filtrate into a second 500-cc. flask, 
add 30 grams of pulverized sodium chloride for each 100 cc, shake until 
dissolved, and dilute to the mark with saturated salt solution. Mix 
thoroughly and filter off the precipitated protein matter on a folded filter. 

2. Extraction and Titration. — Pipette a convenient portion of the 
filtrate (100 to 200 cc), obtained as above, into a separatory funnel. 
Neutralize to litmus-paper with hydrochloric acid (i : 3) and add an excess 
of 5 cc. In the case of salt fish, protein matter usually precipitates on 
acidifying, but this does not interfere with the extraction. Extract care- 
fully with chloroform, using, for 200-cc. aliquots, successive portions of 
70, 50, 40, and 30 cc, and proportional quantities for smaller aliquots. 
To avoid emulsion, shake each time cautiously. The chloroform layer 
usually separates readily after standing a few minutes. If an emulsion 
forms, stir the chloroform layer with a glass rod. If this does not break 
up the emulsion, draw it off into a second funnel and shake sharply once 
or twice. If this also fails, centrifuge the emulsion for a few moments. 
Draw off with great care as much of the clear chloroform solution as 
possible after each extraction. If not contaminated with the emulsion, 
it is unnecessary to wash the chloroform extract. 

Transfer the combined chloroform extract to a dish, rinsing with 
chloroform, evaporate to dryness at room temperature, either sponta- 



FOOD PRESERVATIVES. 895 

neously or in a current of dry air, and dry overnight (or, in case of catsup, 
until no odor of acetic acid can be detected) in a sulphuric acid desiccator. 
Dissolve the residue of benzoic acid in 30 to 50 cc. of neutral alcohol, 
add about one-fourth this volume of water, a drop or two of phenol phtha- 
lein solution and titrate with twentieth-normal sodium hydroxide. One 
cc. of the standard solution is equivalent to 0.0072 gram anhydrous sodium 
benzoate. 

In the absence of a blast an electric fan may be used for evaporating 
the extract. If it is impracticable to evaporate the chloroform sponta- 
neously or by means of a blast it may be transferred from the separatory 
funnel to a 300-cc. Erlenmeyer flask, rinsing the separatory funnel three 
times with 5 or 10 cc. of chloroform. Distil very carefully to about one- 
fifth the original volume, keeping the temperature down so that the 
chloroform comes over in drops, not in a steady stream. Then transfer 
the extract to a porcelain evaporating dish, rinsing the flask three times 
with 5 or 10 cc. portions of chloroform, and evaporate to dryness spon- 
taneously. 

The evaporation of the chloroform is best effected by delivering to the 
dish a blast of air dried by means of a calcium chloride bottle. 

Hilyer Method* — This method is valuable as a check on the La Wall 
and Bradshaw method. After titrating the benzoic acid obtained as 
described in the preceding section, proceed as follows: 

Evaporate to dryness the accurately neutralized solution (which should 
not have even a slight alkaline reaction), and redissolve in a few cubic 
centimeters of alcohol saturated with silver benzoate. Filter if not clear, 
wash with a few drops of alcohol, and treat with 10 to 15 cc. of a saturated 
solution of silver nitrate in alcohol. Collect the precipitate in a Gooch 
crucible, care being taken that the asbestos filter is so prepared as to afford 
as rapid a filtration as possible, wash with alcohol, and finally with a little 
ether, heat in a water-oven until the ether is removed, cool, and weigh. 
Care must be taken to perform all the operations as quickly as possible 
to avoid separation of silver oxide. 

West^s Distillation Method.'^ — i. Apparatus. — The special form of 
double flask for distillation in a current of steam is the same as that em- 
ployed by Hortvet | in determining the volatile acids of wine (Fig. 115). 

* A. O. A. C. Proc, 1908, U. S. Dept. of Agric, Bur. of Chem., Bui. 122, p. 74; Circ. 
66, p. 15. 

t Jour. Ind. Eng. Chem., i, 1909, p. 190. 
t Ibid., I, 1909, p. 31. 



896 FOOD INSPECTION AND ANALYSIS. 

The steam tube leading from the outer to the inner flask, being intro- 
duced half-way up the side of the inner flask, makes it possible to connect 
the apparatus in such a way that at the beginning of the operation the water 
in the outer flask will reach to the height of the contents of the inner flask. 
The side tube leading from the neck of the outer flask is provided with a 
rubber tube and pinch-cock for use in relieving the steam pressure and 
avoiding the danger of drawing the contents of the inner flask over into the 
outer flask. 

2. Process. — Weigh into the inner flask of the apparatus lo grams, 
add 1.5 to 2,0 grams of paraffin free from volatile matter, and connect 
with the condenser. Add 10 cc. of concentrated sulphuric acid, drop 
by drop, through the funnel tube at such a rate as to complete the addition 
in two or three minutes, mix thoroughly by gentle agitation, and allow 
to stand five or ten minutes after all apparent action of the sulphuric 
acid has stopped. Measure 150 cc. of distilled water into the outer 
flask, heat the water slowly to boiling, and continue the boiling until 
100 cc. of distillate have been collected, the rate of distillation being such 
as to yield this amount in twenty-five to thirty minutes. 

Filter the distillate into a separatory funnel, and rinse receiver and 
filter with two lo-cc. portions of water. Shake with three portions of ether, 
using 50 cc, 30 cc, and 20 cc, and wash the combined ether extracts 
by shaking with four 50-cc. portions of water and a last portion of 25 cc, 
which portion should not require more than a drop of tenth-normal alkali 
for neutralization, indicating the complete removal of volatile acids. 
Transfer the ether extract to a tared, wide-mouthed flask, and distil off 
the ether on the water-bath as quickly as possible. At just the point 
where ebullition of the ether ceases, remove the flask from the bath, blow 
air into it to remove the last traces of ether, and dry in a desiccator over 
night, or until constant weight is secured. 

The benzoic acid may also be determined by titration, in which case 
the filtration of the distillate, also the drying and weighing of the acid, 
may be omitted. The crystals of benzoic acid are dissolved in alcohol 
carefully neutralized immediately before each analysis, and the solution 
titrated with tenth-normal alkali. 

SULPHUROUS ACID AND THE SULPHITES. 

Free sulphurous acid in the form of sulphur fumes is extensively 
employed to bleach molasses, to disinfect wine casks, and to bleach and 
preserve dried fruits. This process is known as " sulphuring." It is 



FOOD PRESERVATIVES. 897 

stated that the sulphur dioxide combines with the acetaldehyde of wines 
forming aldehyde-sulphurous acid, which is comparatively harmless. In 
the case of dried fruits it is believed to form compounds with the sugars. 

The sulphurous acid salts most commonly employed as food pre- 
servatives are the bisulphites of sodium and calcium, NaHSOa and 
Ca(HS03)2. Others used to some extent are the normal sodium sul- 
phite, and also potassium and ammonium sulphite. The sulphites are 
usually commercially prepared by passing sulphurous acid gas through 
strong solutions of the carbonates. Acid sulphites are formed by an 
excess of the sulphurous acid in the solution of the sulphite. The acid 
sulphites are distinguishable from the sulphites by their reaction with 
litmus paper, the former being acid, while the latter are neutral or feebly 
alkaline. All of these salts have a bitter, salty, and highly sulphurous 
taste, and possess a very pungent, irritating odor. With the exception 
of normal calcium sulphite, all of the above are readily soluble in water. 

The sulphites are most commonly used as preservatives of fruit juices, 
ketchups, fruit and vegetable pulps, wines, malt liquors, and meat prod- 
ucts. They are frequently mixed with other antiseptics, as with the salts 
of salicylic and benzoic acids. 

Detection and Determination of Sulphurous Acid. — The same methods 
are used for the detection of sulphurous acid as for its quantitative deter- 
mination, except that in the former case weighed quantities need not be 
employed, and the precipitate obtained by the barium sulphite method 
need not be weighed. A qualitative method employing iodate-starch 
paper is described on page 238. 

Distillation Method. — This method is adapted to all food products 
whether solid or liquid. 

Place 50 to 200 grams of the material in a 500-cc. flask, add water, 
if necessary, and 5 cc. of a 20% solution of phosphoric acid, and distil 
in a current of carbonic acid into water containing a few drops of bromine, 
until 150 cc. have passed over. If sulphides are present, as is true of 
decomposed meat products and possibly other foods, the steam from 
the distilling-fiask before entering the condenser should be passed through 
a flask containing 40 cc. of a 2% neutral solution of cadmium chloride * 
of a 1% solution of copper sulphate. f These solutions effectually remove 
the hydrogen sulphide, without retaining any appreciable amount of 



* Home, U. S. Dept. of Agric, Bur. of Chem., Bui. 105, 1907, p. 125. 
t Winton and Bailey, Jour. Amer. Chem. Soc, 29, 1907, p. 1499. 



898 FOOD INSPECTION AND ANALYSIS. 

sulphurous acid. To avoid escape of sulphurous acid the condenser 
tube should dip below the surface of the bromine solution. 

The method and apparatus may be simplified without material loss 
in accuracy by omitting the current of carbon dioxide, adding lo cc. of 
phosphoric acid instead of 5 cc. and dropping into the distilling-fiask a 
piece of sodium bicarbonate weighing not more than a gram, immediately 
before attaching the condenser. 

When the distillation is finished, boil off the excess of bromine, dilute 
to about 250 cc, add i cc. of concentrated hydrochloric acid, heat to 
boiling, and add, drop by drop while boiling, an excess of barium chloride 
solution. Allow to stand overnight in a warm place, filter (preferably 
on a Gooch crucible with a compact mat of woolly asbestos), wash with 
hot water, ignite at a dull red heat, and weigh as barium sulphate. 

Molstad * distils in a current of carbon dioxide gas into 3% hydrogen 
peroxide and titrates the resultant sulphuric acid with N/io sodium 
hydroxide. 

Direct Titration Method.^ — This method is applicable to sauternes 
and other white wines and to beer, but should not be used for other mate- 
rials, unless found by experiment to yield accurate results. 

To 25 grams of the sample, finely divided in water if solid or semi- 
solid, add 25 cc. of a normal solution of potassium hydroxide in a 200-cc. 
flask. Shake thoroughly, and set aside for at least fifteen minutes with 
occasional shaking; 10 cc. of sulphuric acid (i : 3) are then added with 
a little starch solution, and the mixture is titrated with N/50 iodine solu- 
tion, introducing the iodine solution quite rapidly, and adding it till a 
distinct fixed blue color is produced. One cc. of the iodine solution is 
the equivalent of 0.00064 gram SO2. 

FORMIC ACID. 

Formic acid (HCOOH) is a colorless liquid at temperatures above 
8.3° C. It boils at 101° C, has a pungent odor and strong caustic action 
when applied to the skin, causing great pain and ulceration. It occurs 
naturally in the bodies of certain ants (hence the name) and in small 
quantities in various vegetable and animal substances. 

On a commercial scale formic acid is usually prepared by heating 
glycerol with oxalic acid, the glycerol ester first formed being saponified 

*Tids. Kem. Farm., 11, 1914, p. 281. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 90. 



FOOD PRESERVATIVES. 899 

by a fresh portion of the oxaHc acid and the formic acid separated by 
distillation. 

Formerly this acid was considered to be less active as a preservative 
than acetic acid, but more recently it has been shown to be very powerful, 
a water solution containing less than o.i% entirely preventing the growth 
of yeasts and certain bacteria. Recently a 60% solution has come into 
use as a preservative for fruit products. 

Detection of Formic Acid. — Bacon Method.^ — Strongly acidify the 
solution (which must not contain formaldehyde) with phosphoric acid 
and distil about one-third of it. To the distillate add dilute sulphuric 
acid and magnesium filings in sufiicient quantities to cause a vigorous but 
not a violent evolution of hydrogen. In case quite a large quantity of 
acid is present in the distillate it is not necessary to add any sulphuric 
acid. If the amount of formic acid is small (about 0.1%) continue the 
action for one hour; if larger quantities are present the reaction will be 
complete in a few minutes. Test the solution for formaldehyde by the 
methods given on page 881. 

Woodman and Burwell Method.^; — Distil 50 grams of the material 
with 20 cc. of 20% phosphoric acid, heating the liquid during the process 
until 200 cc. have condensed. Mix the distillate with 2 cc. of 30% acetic 
acid, add 20 cc. of milk of lime (100 grams CaO per liter), or sufiEicient to 
neutralize the acid, evaporate to small bulk over a free flame, then to 
dryness on the water-bath, and subject to dry distillation in a test-tube 
heating finally to redness and passing the distillate into 3 cc. of water con- 
tained in another test-tube cooled in ice water. Test the distillate for 
formaldehyde. 

Shannon Method.^ — Distil in a current of steam about 1000 cc. of the 
solution, collecting 2500 cc. of distillate in a receiver containing 5 cc. of 
lead cream. (The latter is prepared by adding sodium hydroxide to a 
solution of lead 'nitrate until a faint pink color appears with phenol- 
phthalein and washing the precipitate 8 to 10 times by decantation.) Shake 
and as the lead dissolves add a few cc. more of the cream until all the formic 
acid is combined. Evaporate to about 50 cc, filter and allow to crystallize 
in a desiccator. Wash the needle-like crystals of lead formate with absolute 
alcohol and dry on filter-paper. 



* U. S. Dept. of Agric, Bur. of Chem., Circ. 74. 

t Tech. Quart., 21, 1908, p. i. 

t Jour. Ind. Eng. Chem., 4, 191 2, p. 526. 



900 FOOD INSPECTION AND ANALYSIS. 

An aqueous solution of the crystals should reduce silver nitrate, mer- 
curic or platinum chloride solution on warming and should yield with 
sulphuric acid on warming in a test-tube, carbon monoxide, which burns 
in the tube. Distilled with concentrated phosphoric acid, the crystals 
yield formic acid, identified by the acid reaction, the reducing action on 
the metallic salts as given above, and the formation of formaldehyde when 
treated according to the Bacon test. 

Determination of Formic Acid. — Fincke Method.^ — Dilute 25 to 
50 grams of the material to 100 cc, add i gram of tartaric acid and distil 
in a current of steam until the distillate amounts to 1000 to 1500 cc. In 
the case of vinegar nearly neutralize with sodium or calcium carbonate 
before distillation. 

Add sodium hydroxide to the distillate to slight alkaline reaction, 
evaporate to 300 cc, add 3 to 5 grams of sodium acetate and sufficient 
mercuric chloride reagent (100 grams of mercuric chloride and 30 grams of 
sodium chloride per liter) so that the amount of mercuric chloride added 
is at least fifteen times the amount of formic acid present. 

If the quantity of formic acid present is minute, the neutralized distil- 
late should be evaporated to 25 cc. and only 0.2 gram of sodium acetate 
and 2 cc. of the mercury reagent added. 

Heat on a steam bath under a reflux condenser for two hours, collect 
the mercurous chloride on a Gooch crucible, wash with water, and finally 
with alcohol and ether. Dry at 100° C. for one hour and weigh. Calculate 
the formic acid, using the factor 0.0975. 

Both Fincke and Kreis f call attention to the formation of formic acid 
from sugars in the presence of acids, hence the necessity for quantitative 
determination, ignoring mere traces. Kreis states that by avoiding the 
addition of acid, heating the distilling flask in a water-bath, and collecting 
I liter of distillate, less than 5 mg, of formic acid are formed from sugars. 
Merl X distils under diminished pressure (10 to 15 mm.), heats in a bath 
at 60° C. ether in a current of air or steam, the temperatures of the boiling 
liquid being about 35 to 43° C, treats the distillate with calcium carbonate, 
and proceeds in other respects as in the regular Fincke method. In this 
manner the formic acid from decomposed sugars does not exceed 1.49 mg. 



* Zeits. Unters. Nahr. Genussm., 21, 1911, p. i' 22, 1911, p. 88; 23, 1912, p. 255; 25, 
1913, p. 386. 

t Mitt. Lebensm. Hyg., 3, 1913, p. 205. 

X Zeits. Unters. Nahr. Genussm., 27, 1914, p. 733. 



FOOD PRESERVATIVES. 901 

Adam * in all the samples of bouillon cubes examined by him found formic 
acid formed by the treatment of starch with nitric acid during manu- 
facture. 

If sulphurous acid is contained in the material, oxidize in an alkaline 
solution with hydrogen peroxide and remove the excess of peroxide with 
freshly precipitated mercuric oxide. In case salicylic acid is present add 
I gram of sodium chloride for each 50 cc. of the distillate. 

To separate from formaldehyde or other aldehydes pass the vapor 
from the distilling flask through a boiling suspension of i gram of calcium 
carbonate in 100 cc. of water before condensing. Separate the suspended 
calcium carbonate by filtering and treat the filtrate as described. Seeker,f 
to avoid the interference of sulphur dioxide, uses barium carbonate instead 
of calcium carbonate. 

Bacon Method. % — Distil the solution containing the formic acid with 
a small quantity of phosphoric acid until the distillate is no longer acid. 
If the volume of the distillate is too large to be conveniently handled, 
neutralize it with sodium hydroxide and evaporate to a convenient volume. 
Add an excess of platinic chloride and sufficient acetic acid to make the 
solution strongly acid (usually about i or 2 cc. of glacial acetic acid for 
less than i gram of formic acid), and boil the solution for one hour, using 
a reflux condenser. Collect the reduced platinum in the usual manner and 
weigh. The weight of the platinum multiplied by 0.472 equals the formic 
acid present. 

FLUORIDES, FLUOSELICATES, AND FLUOBORATES. 

These substances all possess strong antiseptic qualities, and while 
no instances are recorded of the use of the last two classes of compounds 
in this country, the use of fluorides as a preservative of beer is practiced 
to some extent. The salt most commonly used is ammonium fluoride 
(NH4F), preparations of this salt being sold commercially under various 
trade names as beer preservatives. Ammonium fluoride exists as small, 
deliquescent, hexagonal, flat crystals. Its taste is strongly saline. It 
is soluble in water, and slightly soluble in alcohol. Sodium fluoride 
(NaF) occurs as clear, lustrous crystals, soluble in water. 



* Arch. Chem. Mikros., 9, 1916, p. 77. 

t Jour. Assn. Off. Agr. Chem., i, 191 5, p. 264. 

X U. S. Dept. of Agric, Bur. of Chem., Circ. 74. 



902 FOOD INSPECTION AND ANALYSIS. 

Detecton of Fluorides. — Modification of Blarez' Method.^ — Thor- 
oughly mix the sample and heat 150 cc. to boiling. Add to the boiling 
liquid 5 cc. of a 10% solution of barium acetate. Collect the precipitate 
in a compact mass, using to advantage a centrifuge, wash upon a small 
filter, and dry in the oven. Transfer to a platinum crucible, first break- 
ing up the dry precipitate and then adding the filter ash to the crucible. 
Prepare a glass plate (preferably of the thin variety commonly used for 
lantern-slide covers) as follows: First thoroughly clean and polish, and 
coat on one side by carefully dipping while hot in a mixture of equal 
parts of Canauba wax and paraffin. Near the middle of the plate make 
a small cross or other distinctive mark through the wax with a sharp 
instrument, such as a pointed piece of wood or ivory, which will remove 
the wax and expose the glass without scratching the latter. Add a few 
drops of concentrated sulphxiric acid to the residue in the crucible, and' 
cover with the waxed plate, having the mark nearly over the center, and 
making sure that the crucible is firmly imbedded in the wax. Place 
in close contact with the top or unwaxed surface of the plate a cooling 
device, consisting of a glass cylinder the bottom of which is closed with 
a thin sheet of pure rubber. Keep the cylinder filled with ice water, so 
that the wax does not melt. Heat the bottom of the crucible gently over 
a low flame or on an electric stove for an hour. Remove the glass plate 
and indicate the location of the distinguishing mark on the unwaxed 
surface of the plate by means of gummed strips of paper, melt off the 
wax by heat or a jet of steam, and thoroughly clean the glass with a soft 
cloth. A distinct etching will be apparent on the glass where it was ex- 
posed, if fluoride be present. 

Detection of Fluoborates and Fluosilicates. — Nivibre and Hubert 
Method. '\ — To 200 cc. of the sample add lime water to alkaline reaction, 
evaporate to dryness, and ignite. Extract the partially burned residue 
with water acidified with acetic acid and filter. Ignite the insoluble residue 
and extract again with dilute acetic acid, filter, add the second filtrate to 
the first, and test this for boric acid (page 885) . 

Incinerate the filter with the insoluble portion containing calcium 
silicate or fluoride, if present, transfer to a test-tube, mix with some silica, 
and add a little concentrated sulphuric acid. Attach to the test-tube a 
small U-tube containing a very little water. Heat the test-tube for half 



* Mass. State Board of Health An. Rep., 1905, p. 498. Chem. News, 91, 1905, p. 39. 
t Monit. sci., 1895 [4], 9, 324- 



FOOD PRESERVATIVES. 903 

an hour in a water-bath kept below boiling. In the presence of fluoride, 
silicon fluoride will be generated and will be decomposed by the water 
in the U-tube, forming a gelatinous deposit on the walls. 

If both boric and hydrofluoric acids are found, the compound present 
is undoubtedly a borofluoride. If no boric acid is found, but silicon 
fluoride is detected, repeat the operation, but without the added silica. 
If the silicon skeleton is then formed, fluosilicate is indicated. 

BETA-NAPHTHOL 

Beta-naphthol (C10H7OH) is a phenol, occurring naturally in coal- 
tar, but the commercial product is more commonly prepared artificially 
from naphthalene by digesting the latter with sulphuric acid, and fusing 
the product with alkali. It is a colorless, or pale buff-colored powder, 
•with a faint phenolic odor and a sharp taste. It is slightly soluble in water, 
and readily soluble in alcohol, ether, and chloroform. Its melting-point 
is 122° C. In alcoholic solution it is neutral to litmus. 

It is used to some extent in alcoholic solution as a preservative of 
cider. 

Detection of Beta-Naphthol. — Bube * states that if an ethereal extract 
of beta-naphthol is evaporated to dryness, and the residue dissolved in 
hot water made first faintly alkaline with ammonia, and then faintly acid 
with very dilute nitric acid, a beautiful rose color will be developed on 
the addition of a drop of fuming nitric acid or of a nitrite. He declares 
the test to be a delicate one, but it is apparently sometimes obscured by 
interfering substances, which the ether may dissolve. It should also be 
carried out in a faint light, as strong sunlight affects the color. 

Ferric chloride, when applied to an aqueous solution of beta-naphthol, 
produces a greenish coloration. 

Shake about 50 grams of the sample to be tested with chloroform in 
a separatory funnel, evaporate the chloroform extract to a small volume 
(say I or 2 cc), transfer to a test-tube, add 5 cc. of an aqueous solution 
of potassium hydroxide (i : 4), and warm gently. If beta-naphthol is 
present, a deep-blue color will appear in the aqueous layer, turning through 
green to light brown. 

ASAPROL, OR ABRASTOL 

These are trade names for calcium a-mono-sulphonate of beta- 
naphthol, Ca(CioH6S030H)2, a white, odorless, scaly powder, sometimes 

* Analyst, 13, 1888, p. 52. 



904 FOOD INSPECTION AND ANALYSIS. 

slightly reddish, obtained by the action of heated sulphuric acid on beta- 
naphthol, the resulting compound being afterwards treated with a calcium 
salt. It is readily soluble in water and alcohol, and is neutral in reaction. 
Its taste is at first slightly bitter, but rapidly changes to sweet. It decom- 
poses at about 50° C. 

The writer is unaware of any instance of the presence of this substance 
in foods, but its character is such as to adapt it for use as a preservative 
of wines and possibly other food products. It has long been regarded 
as a possible preservative, and the analyst should be prepared to encounter 
it at any time. 

Detection of Asaprol. — Sinahaldi's Method.'^ — The portion of the 
solution to be tested (say 50 cc.) is made slightly alkaline with ammonia, 
and shaken with 10 cc. of amyl alcohol in a separatory funnel. Alcohol 
is often useful in breaking up an emulsion if there is one. Separate the 
amyl alcohol extract, which if turbid is filtered, and evaporate to dry- 
ness. Wet the residue with about 2 cc. of nitric acid (i : i), heat on the 
water-bath till the volume is about i cc, and wash with a few drops of 
water into a narrow test-tube. Next add about 0.2 gram of ferrous sul- 
phate and ammonia in excess, a drop at a time, constantly shaking the 
solution. If a reddish-colored precipitate is formed, it is dissolved by 
the addition of a little sulphuric acid, and further additions of ferrous 
sulphate and ammonia are made as before. When a dark-colored cr 
green precipitate appears, add 5 cc. of alcohol, dissolve in sulphuric acid, 
shake, and filter. If abrastrol be present to the extent of 0.0 1 gram or 
more, a red coloration is observed, while in its absence, the filtrate is color- 
less or faintly yellow. 

If the solution to be tested is a fat, it should be melted and extracted 
with hot 20% alcohol, which is evaporated to dryness, and the above test 
carried out on the dry residue. 

* Mon. Sci., 1703 (4), 7, p. 842; U. S. Dept. of Agric, Bur. of Chem., Bui. 59, p. 91. 



CHAPTER XIX. 
ARTIFICIAL SWEETENERS. 

Under this head are included the intensely sweet coal-tar derivatives, 
such as saccharin, dulcin, and glucin, that possess no food value whatever 
in themselves. From their high sweetening power, in some cases several 
hundred times that of cane sugar, they are capable, when used in minute 
quantity, pf imparting an appropriate degree of sweetness to food products, 
which, on account of the use of inferior materials, or by reason of the 
presence of inert or less sweet adulterants, would otherwise be lacking 
in this property. 

Such canned vegetables as sweet corn and peas are subject to treat- 
ment with saccharin, especially if by their age and condition before can- 
ning they are wanting in the sweet, succulent taste inherent in the fresh 
product. 

The sweetening power of commercial glucose is considerably less 
than that of cane sugar, so that when large admixtures of the glucose are 
used in such products as jellies, jams, honey, molasses, maple syrup, 
etc., to the exclusion of cane sugar, the presence of the glucose might in 
some cases be suggested by the bland taste of the food, unless reinforced 
by one of the artificial sweeteners. 

The analyst should therefore be on the outlook for one or another 
of these concentrated sweetening agents in all of the above classes of 
foods, especially in saccharine products wherein glucose is found to pre- 
dominate largely over the cane sugar, while the taste is not lacking in 
sweetness. 

SACCHARIN. 

Saccharin or Gluside, Benzoyl sulphimide (C6H4.CO.SO2NH), is a 
white powder, composed of irregular crystals, whose melting-point, when 
pure, is about 224° C. It is prepared from toluene, which by treatment 
with concentrated sulphuric acid is first converted into a mixture of 

905 



906 FOOD INSPECTION AND ANALYSIS. 

ortho- and para-toluene sulphonic acids. These are further converted into 
corresponding chlorides, and from the orthochloride, by treatment with 
ammonia, the imide is formed. It is soluble in 230 parts of cold water, 
30 parts of alcohol, and 3 parts of ether. It is sparingly soluble in chloro- 
form, but readily soluble in dilute ammonia. It is from 300 to 500 times as 
sweet as cane sugar, and, unlike cane sugar, it is not, when pure, charred 
by the action of concentrated sulphuric acid even on heating. Its aque- 
ous solution is distinctly acid in reaction. Pure saccharin, when heated 
under diminished pressure, can be sublimed without decomposition. 

The addition of i part of saccharin to 1000 parts of commercial glucose 
renders the latter as sweet as cane sugar. 

The sodium salt of saccharin is readily soluble in water, and has nearly 
the same sweetening power as saccharin. 

Saccharin, according to Fahlberg and List,* has antiseptic properties. 
Squibb states that it is about equal to boric acid in this respect. 

The use of saccharin in foods, other than those designed for invalids, 
is not allowed under the federal law.f This decision was reached after 
the Referee Board found that quantities over 0.3 gram and especially over 
I gram per day used for a considerable time were liable to produce digestive 
disturbances. J 

Detection of Saccharin in Foods. — If the sample to be tested is a solu- 
tion or syrup, render it acid, if not already such, with phosphoric acid, 
and extract with ether. In case of canned vegetables and similar goods, 
finely divide the material by pulping or maceration in a mortar, dilute 
with water, and strain through muslin. Acidify the filtrate, and extract 
with ether. § If an emulsion forms, use a centrifugal machine (p. 21). 
Separate the extract, evaporate off the ether, and test the residue for 
saccharin as follows : 

(i) Add to the residue, if it tastes sweet, a few cubic centimeters of 
hot water, or preferably a very dilute solution of sodium carbonate, in 
which saccharin is more soluble. An intensely sweet taste is indicative 
of its presence. This test, if applied directly, will sometimes fail, espe- 
cially in the case of beer, by reason of the extraction by the ether of various 



* Jour. Soc. Chem. Ind., 4, p. 608. 
t Food Inspection Decision 146. 
t U. S. Dept. of Agric, Rep. 94, Washington, 1911. 

§ Allen states that a purer residue is obtained if the sample of beer be treated with lead 
acetate, and filtered before extraction with ether. 



ARTIFICIAL SWEETENERS. 907 

bitter principles, such as hop resins, which by their strong, bitter taste 
mask the sweet taste of saccharin in the residue. Spaeth * recommends 
that such bitter substances be removed before extraction, which is done 
by treatment of 500 cc. of the beer with a few crystals of copper nitrate, 
or with a solution of copper sulphate. The flocculent precipitate formed 
need not be filtered off, but the liquid is preferably concentrated by evap- 
oration to syrupy consistency, acidified with phosphoric acid, and ex- 
tracted with three successive portions of a mixture of ether and petro- 
leum ether. After extraction, separation, and evaporation of the solvent, 
dissolve the residue in weak sodium carbonate. As small a quantity 
as 0.001% of saccharin can be detected in the final alkaline solution by 
its sweet taste. 

(2) Bornstein's TesL-\ — Heat the residue from the ether extraction 
of the acidified sample with resorcin and a few drops of sulphuric acid 
in a test-tube till it begins to swell up. Remove from the flame, and, 
after cooling till the action quiets down, again heat, repeating the heating 
and cooling several times. Finally cool, dilute with water, and neutralize 
with sodium hydroxide. A red-green fluorescence indicates saccharin. 
Gantter | states that it is useless to apply this test to beer, in view of the 
fact that ordinary hop resin gives the same fluorescence. 

(3) Schmidt's Test.^ — The residue is heated in a porcelain dish with 
jibout a gram of sodium hydroxide || for half an hour at a temperature 
of 250° C, either in an air-oven or in a linseed oil bath. This converts 
ihe saccharin if present into sodium salicylate. Dissolve the fused mass 
in water, acidify, and extract the solution with ether. Test the ether 
le.idue in the regular manner for salicylic acid with ferric chloride 
(p. 888). This test can obviously be applied only in the absence of 
salicylic acid, which should first be directly tested for. 

It is recommended that a mixture of equal parts of ether and petroleum- 
ether is preferable to the use of ether alone as a solvent of saccharin, as 
such a mixture, while readily dissolving saccharin, does not, like ether, 
dissolve other substances, which might form salicylic acid when fused 
with sodium hydroxide. 

Determination of Saccharin. — When saccharin is fused with an alkali 
and potassium nitrate, the sulphur is oxidized to sulphuric acid. On 

* Zeits. angewandte Chem., 1893, p. 579. 

t Zeits. anal. Chem., 27, p. 165. 

J Ibid., 32, 309. 

§ Rep. Anal. Chem., 30; Abs. Analyst, 12, p. 200. 

!j Potassium hydroxide cannot be used instead of sodium hydroxide for the fusion. 



908 FOOD INSPECTION AND ANALYSIS. 

this principle depends the following method of Reischauer:* A known 
quantity of the beer or other liquid to be tested is concentrated by evapo- 
ration to about one-third its original volume, acidified with phosphoric 
acid, and extracted by repeated portions of ether. The combined ether 
extract is evaporated to small volume, and transferred to a platinum 
crucible, in which it is further brought to dryness. It is then cautiously 
ignited with a mixture of about 6 parts sodium carbonate and i part potas- 
sium nitrate. Dissolve the fusion in water, acidulate with hydrochloric 
acid, and determine the sulphuric acid in the usual manner with barium 
chloride. The weight of the precipitated barium sulphate, multiplied 
by 0.785, gives the weight of saccharin. In view of the fact that only 
small quantities of saccharin are used in beer and other foods, it is best 
to employ a large portion of the sample for analysis. 

DULCIN. 

Dulcin or sucrol, para-phenetol carbamide (C2H5O.CeH4.NH.CO.NH2) 
is a white powder, composed of needle-like crystals, sparingly soluble 
in cold water, ether, petroleum ether, and chloroform. It dissolves in 
800 parts of cold water, 50 parts of boiling water, and 25 parts of 95% 
alcohol. It is readily soluble in acetic ether. Its melting-point is about 
173° C. It is not readily sublimed without decomposition. Dulcin is 
about four hundred times sweeter than cane sugar. 

When a mixture of dulcin and dilute sodium hydroxide is subjected to 
distillation, phenetidin goes over with the steam into the distillate. When 
this is heated with glacial acetic acid, phenacetin is formed, which may 
be tested for as follows: Boil with hydrocliloric acid, dilute with water, 
cool, filter if turbid, and add a few drops of a solution of chromic acid. 
A deep-red color indicates phenacetin. 

Detection of Dulcin in Foods. — In view of the comparatively slight 
solubility of dulcin in ether and chloroform, acetic ether is the best solvent 
for purposes of removing it from foods, first making it alkaline. 

(i) Belli er's Method. ■\ — A portion of the sample to be tested is made 
alkaline and extracted with acetic ether. In the case of certain products 
it is best to subject them to varied preliminary treatment, depending on 
the case in hand. With such products as thin fruit syrups, simply make 
alkaline and shake out with acetic ether. In the case of thick fruit syrups, 
confectionery, and preserves, dilute with water, add an excess of basic 

* Abst. Analyst, ii, p. 234. 

t Ann. de Chim. Anal., 1900, V, pp. 333-337; Abs. Analyst, 26, p. 43. 



ARTIFICIAL SWEETENERS. 909 

lead acetate, remove the lead by precipitation with sodium sulphate, 
filter, and make the filtrate alkaline. 

With wines, add 2 grams of mercuric acetate and a slight excess of 
ammonia, shake, and filter. 

With beer, add to 200 cc. 2 or 3 grams of powdered sodium phospho- 
tungstate, and a few drops of sulphuric acid, shake, allow to stand for a 
few minutes, and filter. Make the filtrate alkaline with ammonia. 

Having thus obtained a clarified solution, use from 50 to 200 cc. of 
neutral acetic ether to say 500 cc. of the alkaline solution, and shake 
in a separatory funnel. Separate the extract, filter, and evaporate to 
dryness. If the dulcin exceeds 0.04 gram per liter, crystals will be appar- 
ent in the residue. If fats and resins are present in the residue, make 
repeated extractions with hot water, and evaporate to dryness. The 
purified residue is finally brought to dryness in a porcelain dish, and 
treated with i or 2 cc. of sulphuric acid and a few drops of a solution 
of formaldehyde. Let it stand for fifteen minutes, and afterwards dilute 
with 5 cc. of water. A turbidity or precipitate indicates dulcin. 

(2) Jorissen's Test.^ — The residue from the acetic ether extract of 
an alkaline solution of the sample is treated with 2 or 3 cc. of boiling 
water in a test-tube, and a few drops of mercuric nitrate f are added. 
Heat the tube and its contents for five minutes in a boiling water-bath, 
withdraw, and disregarding any precipitate, add a small quantity of lead 
peroxide. On the subsidence of the precipitate, which quickly occurs, 
a fine violet color appears for a short time in the clear upper layer in 
presence of 0.00 1 gram of dulcin. 

(3) Morpurgo's Method.X — To the acetic ether residue, evaporated to 
dryness in a porcelain dish, add a few drops of phenol and concentrated 
sulphuric acid, and heat a few minutes on the water-bath. After cooling, 
transfer to a test-tube, and with the least possible mixing pour ammonia 
or sodium hydroxide over the surface. A blue zone at the plane of con- 
tact between the two layers indicates dulcin. 

Determination of Dulcin. — For a quantitative determination, Bellier's 
method is carried out on a weighed or measured portion of the sample, 
as fellows: In the case of alcoholic beverages first expel the alcohol by 

* Chem. Zeit. Rep., 1896, p. 114. 

t The mercuric nitrate is prepared by dissolving 2 grams of mercuric oxide in dilute 
nitric acid, adding sodium hydroxide solution till a slight permanent precipitate is formed, 
diluting to 15 cc, and decanting the clear liquid. 

X Zeits. anal. Chem., 1896, 35, p. 104; U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 
p. 89. 



910 FOOD INSPECTION AND ANALYSIS. 

evaporation, and make up to the original volume with water. Treat 
the various food preparations with the appropriate clarifying reagents, 
as in Bellier's qualitative test (p. 908), and, after filtering and making 
alkaline, extract twice with 50 cc. each of acetic ether. The residue 
is purified if necessary by extraction with hot water as above described, 
and the final residue is dissolved in 1 to 5 cc. of concentrated sulphuric 
acid. A few drops of formaldehyde are added. The solution is allowed 
to stand for fifteen minutes, and then diluted to ten times its volume 
with distilled water. After twenty-four hours, collect the precipitate on a 
tared filter, wash with water, dry, and weigh. 

GLUCIN. 

This comparatively new sweetening agent is the sodium salt of a 
mixture of the mono- and di-sulphonic acids of a substance having the 
composition CigH^gN^. In the market it appears as a light-brown powder, 
readily soluble in water. It is insoluble in ether and chloroform. It 
decomposes without melting at about 250° C. It is three hundred times 
sweeter than cane sugar. 

A color reaction with glucin is obtained by dissolving it in dilute 
hydrochloric acid, cooling by immersing the test-tube in water, and to 
the cold solution adding a little sodium nitrite solution. Finally, to the 
liquid is added a few drops of an alkaline solution of beta-naphthol, and 
a red coloration is produced. With resorcin or salicylic acid in alkaline 
solution, the color will be yellow. 



CHAPTER XX. 

FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 

Of the three great groups of organic compounds essential for nutri- 
tion, the fats and proteins in a state of purity are almost tasteless, as is 
also true of starch, dextrin, and cellulose of the carbohydrate group. 
Only the sugars have a pronounced taste. The flavor of food products, 
aside from their sweetness, is largely due to minor constituents, such 
as organic acids, ethers, essential oils, etc., which serve chiefly to render 
the products acceptable to the palate, thereby contributing to their 
digestibility. Many culinary preparations lacking in flavor, but not in 
nutritive value, are commonly mixed with substances which supply this 
deficiency. Spices and flavoring extracts belong to the class of materials 
added mainly if not entirely for their zest-giving properties. 

By far the most extensively used flavoring extracts are those of vanilla 
and lemon, and in comparison with these the sale of all other varieties 
is comparatively insignificant. These two favorite extracts are employed 
in nearly every household, and form a necessary adjunct to almost all 
forms of desserts, cakes, and confections, as well as to a wide variety 
of commercial preparations. Others of some importance are extracts of 
orange, almond, wintergreen, peppermint, rose, and certain spices. Imita- 
tion fruit flavors are used in cheap confectionery, ice cream, etc., and 
are of questionable wholesomeness. 

VANILLA EXTRACT. 

The Vanilla Bean is the source of pure vanilla extract, besides being 
used in chopped form directly as a flavoring agent. It is the fruit of 
the plant of the Vanilla planijolia, or flat-leaved vanilla. This climbing, 
perennial plant belongs to the orchid family, and is indigenous to Central 
and South America and the West Indies, but by far the highest prized 
beans are cultivated in Mexico. While different varieties differ in some 
details, the best cured beans of commerce, as a rule, are from 20 to 25 cm. 
in length and from 4 to 8 mm. thick, drawn out at their ends and curved 

911 



912 FOOD INSPECTION AND ANALYSIS. 

at the base. They are rich dark brown in color, of a soapy or waxy 
nature to the touch, deeply rifted lengthwise, and covered with tine frost - 
like crystals of vanillin. When cut cross-wise, the bean exudes a thick, 
odorless juice, containing calcium oxalate crystals. 

The cross-section of the bean is ellipsoidal in shape. The thick 
brown walls inclose a triangular cavity, in which are the lobed placentas. 
Between these are papillae, secreting a finely granular, yellow, balsam- 
like substance that contributes much to the flavor of the extract, and 
helps to give the cut bean its dehcious odor. 

When first gathered, the beans are yellowish green, fleshy, and with- 
out odor, developing their pecuhar consistency, color, and smell by the 
process of fermentation or " sweating," which differs in various countries. 
According to the best methods the beans are sun-dried for nearly a month, 
being alternately pressed lightly between the folds of blankets, and 
exposed to the air. After the curing, they are packed in bundles. 

Quicker methods of curing consist of the use of artificial heal and 
calcium chloride for drying, but the products so prepared are considered 
inferior in quality. 

The Mexican vanilla beans are of the choicest grade, and command 
a high price, sometimes reaching fifteen dollars per pound. The Bourbon 
beans, grovm in the Isle of Reunion, are next in grade. These beans 
ire shorter than the Mexican and much less expensive. They resemble 
the Tonka bean in odor. Beans from Seychelles and Mauritius are 
even shorter than the Bourbon beans, and are largely exported to England. 
Cheaper varieties are those from South America, which do not bring 
half the price of the Mexican beans, and the cheapest are the Tahiti beans 
and so-called " vanillons," or beans of the wild vanilla {Vanilla poinpona). 
These latter are used more in sachet powders and perfumes, possessing 
an odor not unlike heliotrope. 

Composition of the Vanilla Bean. — The following are results of the 
analyses of two varieties of vanilla beans, according to Konig: 

A. B. 

Water 25.85 30.94 

Nitrogen bodies 4-87 2.56 

Fat and wax 6.74 4.68 

Reducing sugar 7.07 9.12 

Non-nitrogen substances 30-5° 32-9° 

Cellulose 19.60 15-27 

Ash 4-73 4-53 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 913 

Vanillin.— This body (CsHgOs) is the methyl ether of protocatechuic 
aldehyde, and often occurs on the surface of the bean in fine crystalline 
needles. It has a sharp but pleasant flavor, is soluble with difficulty 
in cold water, but readily soluble in hot water, ether, alcohol, and chloro- 
form. Its melting-point is 80° to 81° C. and it sublimes at 280°. It 
is present in vanilla beans according to Winton and Berry * in amounts 
varying from 1.20% to 3.5096. While the lowest percentage was found 
in the cheapest bean (Tahiti) the highest was found in a bean of medium 
quality (Comores). Mexican beans, the choicest on the market, contained 
1.80% to 2.20%. 

While vanillin may be readily extracted by alcohol and other solvents 
from the beans, such a product would be far too expensive to compete 
with the commercial synthetic vanillin, an artificial product, chemically 
identical with the vanillin from the bean. Synthetic vanillin was formerly 
made from the glucoside coniferin by oxidation with chromic acid. It 
is now largely obtained by oxidizing the eugenol of clove oil with alkaline 
potassium permanganate. 

If ferric chloride be added to an aqueous solution containing vanillin, 
a dark-blue coloration will be produced. 

Besides vanillin, the bean contains wax, fat, sugar, tannin, gum, resin, 
and delicate odoriferous principles not yet studied. 

Exhausted Vanilla Beans are sometimes found on sale, which have 
been deprived of their vanillin by being soaked in alcohol, after which 
they are coated with some artificial substitute, presenting the same frosty 
appearance as the natural vanillin crystals. This may be accomplished 
by rolling the beans in benzoic acid. Benzoic acid crystals are readily 
distinguished from those of vanillin under the microscope. 

Preparation of Vanilla Extract. — Vanilla extract is a dilute alcoholic 
tincture of the vanilla bean, sweetened by cane sugar. To be perfectly 
pure it should contain no other added substances, with the possible excep- 
tion of glycerol, and many of the best brands are free from this. In 
practice it is ^'arIously prepared, but the following method of the U. S. 
Pharmacopoeia (1890) is a typical one: 

" Vanilla, cut into small pieces and bruised, 100 grams. 

" Sugar, in coarse powder, 200 grams. 

" Alcohol and water, each, a sufficient quantity to make 1000 cc. 

" Mix alcohol and water in the proportion of 650 cc. of alcohol to 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 152, 1912, p. 146. 



914 FOOD INSPECTION AND ANALYSIS. 

350 cc. of water. Macerate the vanilla in 500 cc. of this mixture for 
twelve hours, then drain off the liquid and set it aside. Transfer the 
vanilla to a mortar, beat it with the sugar into a uniform powder, then 
pack it in a percolator, and pour upon it the reserved liquid. When this 
has disappeared from the surface, gradually pour on the menstruum, 
and continue the percolation, until 1000 cc. of tincture are obtained." 

Composition of Authentic Extracts. — The tables on pp. 915 and 916 
gives summaries of analyses by Winton and Berry * and Winton, Albright, 
and Berry f of extracts made by the U. S. P. process (1890) from different 
varieties, grades, and lengths of vanilla beans. As the process employed 
did not exhaust the beans as thoroughly as certain commercial processes 
involving soaking the beans for weeks or even months, the residues after 
preparing the U. S. P. extracts were further exhausted by soaking for five 
months in 60% alcohol and the extracts thus obtained analyzed with the 
results summarized at the bottom of the first table. 

A study of the average figures for the different grades and different 
lengths, irrespective of variety, showed an increase of vanillin but a decrease 
in normal lead number and color value from the lowest to the highest 
grade and also from the shortest to the longest bean. 

Influence of Different Menstrua on Composition. — Winton and his 
coworkers have found that the composition of the extract was not 
affected by omission of the sugar entirely, and also that when glycerol was 
substituted for sugar the only constant affected was the color value, which 
was somewhat increased. When 35% alcohol was substituted for the 62% 
alcohol of the above process the percentage of vanillin was not altered, 
but the normal lead number, the percentages of color in the lead filtrate 
and insoluble in amyl alcohol and the ash were increased while the color 
value of the extract itself and the acidity were decreased. In the prepara- 
tion of a pure extract the use of alcohol weaker than 45% is not com- 
mercially practicable owing to difficulties in percolation. 

Dean and Schlotterbeck,J in preparing vanilla extract with 50% alcohol 
alone and with 50% alcohol containing 0.4% of potassium carbonate, 
obtained the following results: normal lead number 0.57 and i.oo, red 
23 and 39, yellow 76 and 96, and ratio of red to yellow i : t^.t^ and i : 2.5 
respectively. Results using smaller amounts of alkali were intermediate. 
A better flavor was obtained without the addition. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 152, 1912, p. 146. 
t Jour. Ind. Eng. Chem., 7, 1915, p. 516. 
X Ibid., 8, 1916, pp. 607, 703. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 



915 



The same authors have made extensive investigations on the influence 
of method of preparation on the quality of the extract. 



COMPOSITION OF AUTHENTIC VANILLA AND TONKA EXTRACTS 





So, 


C 
v 

m 

a 
►J 


1 
> 


•0 

6 ^ 
■z 


Color Value. 


1 
Per Cent ! 
of Total 
Color in 

Lead 
Filtrate. 


Ratio of 
Red to 

Yellow. 






Extract 
(Total 
Color). 


Lead 
Filtrate.* 




030 


Variety 

of 

Bean. 











13 


-d 

(U 

Pi 




v 




Jo a 




13 


cm. 

23 
15 
19 

22 

10 

16 

22 
10 
16 

23 
II 
16 

21 
10 
15 


% 

0.20 
o.is 
0.17 

0.22 
0.13 
0.18 

0.21 
0.16 
0.19 

0.30 
0. 16 
0.22 

0.31 
0.12 
0.18 

0.23 
0.19 
0.21 

0.08 
0.07 
0.08 


% 

0.68 
0.47 
0.58 

0.63 
0.44 
0.52 

0.60 
0.4s 

o.si 

0.63 
0.40 
0.50 

0.74 
0.40 
0.59 

0.58 
0.49 
0.52 

0.67 
0.S7 
0.62 


56 
19 
32 

55 
22 
30 

SO 
22 
33 

47 

25 

34 

40 
22 
31 

50 

42 
46 

61 
40 
48 

45 
44 

44 

17 
15 
16 
42 

S 
5 
S 

56 
IS 
32 

17 
4 
9 


154 

55 
97 

127 
65 
94 

162 

77 
107 

148 

85 

III 

140 
70 
99 

ISS 
117 
134 

195 
I4S 
162 

177 
130 
ISO 

SO 

40 

4S 

107 

19 
18 
19 

177 
40 
102 

62 
21 
32 


2.0 
i.o 
i.S 

2.4 
1-4 
1.9 

3.4 
1.0 

1.8 

2.6 
1.4 
2.0 

2.6 
1.4 
1.9 

2.6 
1.8 
2.3 

7.6 
1.4 
4-3 

3.2 
2.4 
2.9 

0.6 
0.6 
0.6 
1.4 

O.S 
o.S 
O.S 

li 
1.8 

0.5 

O.I 

0.3 


8.0 
4.8 
6.5 

8.2 
S.8 
7.0 

14.6 
S-O 
7.9 

ii-S 
6.2 
8.7 

12.6 
6.0 

7.7 

10.4 
6.8 
8.S 

32.6 
6.4 
18.2 

13.4 
10.4 

13. I 

3.5 
3.1 
3.3 

6.6 

2.4 
2.4 
2.4 

14.6 
3.1 
7.6 

2.2 
0.8 
1.2 


% 

6 

4 
5 

8 
4 
6 

7 
4 
5 

7 

i 

8 
5 
6 

6 

4 
S 

12 
4 
8 

7 
5 
6 

4 
4 
4 
3 

10 
10 
10 

8 
4 
6 

7 
2 
3 


% 

9 
5 

7 

10 
S 
8 

9 
6 
8 

9 
6 
8 

9 
6 
8 

6 
6 
6 

17 
4 
II 

10 
6 
8 

8 
7 
8 
6 

13 
13 
13 

10 
5 
8 

6 
2 

4 


I : 

3.8 
2.6 
3.1 

3.9 
2.3 
3.2 

3.6 

2.5 

3.2 

3.5 
2.7 
3-2 

3.8 

2.8 

3.2 

3.1 
2.5 
2.9 

3.6 

3-2 

3.4 

3.9 
3.0 

3-4 

3.0 
2.7 
2.9 
2.5 

3.8 
3.6 
3.7 

3.9 

2.3 
3.2 

5-7 
2.5 
3.4 


i: 

5.6 
4.0 
4-S 

5.0 
2.8 
3.8 

5.0 

4.0 
4-S 

S-i 
3-5 
45 

5.3 

3.4 
4.1 

4.0 
3-5 
3.8 

4.6 
4.1 
4-3 

4-3 
4.1 
4.2 

5.8 

5-2 

5-5 

4-7 

4.8 
4.8 
4.8 

5.8 
2.8 
4.2 

6.5 
3.0 
4.6 






24.4 






19.0 






21.2 




16 






30.3 






21.3 






26.6 


Seychelles 


9 


29.4 






22.7 






25.6 


Madagascar 


9 


30.3 






23.2 






26.8 




16 






30.3 






20.4 






26.7 


South American. . . 


3 


29.4 








20.0 








23-3 




3 


20 
12 
16 

20 
10 
IS 






50.0 






22.7 






36.1 




3 






0.24 0.61 
0.22 0.44 

0.23 O.'JO 


35. 7 






32.2 






34 5 


Tahiti 


2 


0. II 
0. II 
0. II 

0.06 


o.so 

0.44 
0.47 

0.S2 

0. 11 
0. II 
O.II 

0.74 

0.40 
0.S4 

O.II 

0.03 

0.05 






18.8 








16.0 








17.4 


Vanillons 

Tonka Beans t- • • • 


I 
2 




22.2 
31.2 










30.3 










30.8 


All Analyses t 


71 


23 
10 
16 

23 
10 
16 


0.31 

0. II 

0. 19 
0.07 

O.OI 

0.03 


35.7 












25-5 


All Analyses J 

(2d Extraction) 


71 























* Calculated to volume of extract. 

t Coumarin: Maximum, 0.27%; minimum, 0.22%; average, 0.25%. 

J Excluding Ceylon, Vanillons, and Tonka Beans. 



916 ■ FOOD INSPECTION AND ANALYSIS. 

COMPOSITION OF AUTHENTIC VANILLA AND TONKA EXTRACTS 



Variety 

of 
Bean. 



Acidity of Extract, 

cc. N/io Alkali 

per loo cc. 



Mexican: 

Maximum. . . 

Minimum. . . 

Average 

Bourbon: 

Maximum. . . 

Minimum. . . 

Average 

Seychelles: 

Maximum. . . 

Minimum . . . 

Average 

Madagascar: 

Maximum. . . 

Minimum . . . 

Average 

Comores: 

Maximum. . . 

Mmimum . . . 

Average 

South American 

Maximum. . . 

Minimum. . . . 

Average 

Ceylon: 

Maximum. . . 

Minimum . . . 

Average 

Java: 

Maximum. . . 

Minimum . . . 

Average 

Tahiti: 

Maximum . . . 

Minimum . . . 

Average 

Vanillons 

Tonka beans: 

Maximum. . . 

Minimum . . . 

Average 

All Analyses: * 

Maximum. . . 

Minimum . . . 

Average 



52 
42 
46 

51 
35 

40 

42 
35 
39 

47 
42 
45 

47 
34 
40 

52 
44 
49 

49 
33 
39 

52 

45 



33 
30 
31 
38 

5 
5 
5 

52 
30 
42 



o 



35 
26 
31 

39 
14 
28 

37 
32 

35 

45 
28 
34 

37 
30 
33 

26 
23 
24 
34 

5 
5 
5 

42 
14 
30 



Ash, 
Gram per 100 cc. 



0.422 
o. 297 
0.359 

0.373 
0.263 
0.317 

0.316 
0.251 
0.293 

0.326 
o. 220 
o. 284 

0.432 
o. 229 
0.333 

0.344 
0.30s 
0.32s 

0.443 
0.361 
0.409 

0.349 
o. 290 
0.3II 

0.288 

0.221 
a. 254 
0.263 

o. 132 
o. 163 

0.147 

0.432 
o. 220 

0.319 



v2 



0.349 
o. 246 
0.301 

0.319 
o. 220 

0.259 

o. 262 
0.213 
0.243 

0.271 
0.193 
0.239 

0.3S7 
o. 182 
o. 272 

0.29s 
0.261 
0.276 

0.386 
0.313 

0.354 

o. 299 
o. 246 
0.26s 

0.249 
0.179 

o. 214 
o. 214 

O. 122 

o. 156 

0.139 

0.3S7 
o 179 
0.26s 






0.073 
0.037 
0.058 

0.080 
0.043 
0.058 

0.058 
0.038 
0.050 

0.060 
0.027 
0.045 



0.037 
0.061 

O.OS4 
0.044 
0.049 

0.060 
0.048 
0.05s 

0.050 
0.044 
0.046 

0.042 
0.039 
0.040 
0.048 

o. 010 
0.007 
0.008 

0.081 
0.027 
0.054 



Alkalinity of Ash, 

cc. N/io Acid 

per 100 cc. 



S3 
36 

45 

47 
35 
40 

47 
34 
39 

46 
34 
39 

54 

45 

42 
38 
40 

56 

43 
49 

49 
38 
42 

37 
■30 
33 
38 

IS 
16 
IS 

54 
30 
42 






40 
29 
35 

34 
25 
27 

30 

24 
27 

13 
26 
28 

38 



30 
26 
28 

44 
33 
38 

38 
31 
34 

29 
23 
26 
30 



14 



t* Excluding Ceylon, Vanillons, and Tonka beans. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 917 

The Tonka Bean forms the basis of many of the cheaper so-called 
vanilla extracts on the market. It is the seed of the large tree, native to 
Guiana, known as Dipterix (or Coumarouna) odorata. The pods arc 
almond-shaped, and contain a single seed, from 3 to 4 cm. long, shaped 
like a kidney bean, of a dark-brown color, having a thin, shiny, rough, 
brittle skin, and containing a two-lobed oily kernel. 

Coumarin (CgHgOa), the active principle of the Tonka bean, is the 
anhydride of coumaric acid. It occurs in the crystalhne state between 
the lobes of the seed kernel. Coumarin occurs also in many other plants. 
It may be extracted from the beans by treatment with alcohol. It crys- 
tallizes in slender, colorless, needles, melting at 67° C. It has a fragrant 
odor and burning taste. It is very slightly soluble in cold water, but 
readily soluble in hot water, ether, chloroform, and alcohol. One pound 
of cut beans yields by alcoholic extraction about 108 grains of coumarin. 
The latter may be synthetically prepared by heating salicylic aldehyde 
with sodium acetate and acetic anhydride, forming aceto-coumaric acid, 
which decomposes into acetic acid and coumarin. 

The author has found that an aqueous solution of coumarin, unhke 
vanillin, forms a precipitate when iodine in potassium iodide is added in 
excess, the precipitate being at first brown and flocculent, afterwards, 
on shaking, clotting together to form a dark-green, curdy mass, leaving 
the liquid perfectly clear. 

U. S. Standards. — Vanilla extract is the flavoring extract prepared 
from the vanilla bean, with or without sugar or glycerin, and contains in 
100 cc. the soluble matters from not less than 10 grams of the vanilla bean. 
Vanilla bean is the dried, cured fruit of Vanilla planifolia Andrews. 
Tonka extract is the flavoring extract prepared from tonka bean, with 
or without sugar or glycerin, and contains not less than 0.1% by weight 
of coumarin extracted from the tonka bean, together with a correspond- 
ing proportion of the other soluble matters thereof. 

Tonka hean is the seed of Coumarouna odorata Aublet {Dipteryx 
odorata (Aubl.) Willd.). 

The Adulteration of Vanilla Extract consists chiefly in the use of 
coumarin or extract of the Tonka bean, and in the substitution of artifi- 
cial vanillin, either alone or with coumarin, for the true extractives of 
the vanilla bean. Imitation vanilla flavors more often consist of a 
mixture of either tincture of Tonka or coumarin with vanillin in weak 
alcohol, colored with caramel, or occasionally with coal-tar colors. Or 
the exhausted marc from high-grade vanilla extract is macerated 
with hot water and extracted, the extract being reinforced with 



918 FOOD INSPECTION AND ANALYSIS. 

artificial vanillin or coumarin, or both. A pure vanilla extract possesses 
certain peculiarities with regard to its resins and gums that distinguish 
it from the artificial, or indicate whether or not it has been tampered 
with. While it is possible to introduce artificial resinous matter in the 
adulterated brands with a view to deceiving the analyst, it is almost 
impossible to do this without detection, since different reactions are 
readily apparent in this case from those of the pure extracts. 

Prune juice is said to be used to give body and flavor to vanilla 
extract. The writer has found spirit of myrcia or bay rum in a sampk 
of alleged vanilla extract, containing also vanillin and coumarin. The 
adulterant in this sample was present to such an extent as to be unmis- 
takable by reason of the odor. 

Factitious Vanilla Extracts are ordinarily indicated (i) by the presence 
of coumarin, (2) by the peculiar reactions of the resinous matter, or by 
the entire absence of these resins, (3) by the scanty precipitate with lead 
acetate, and (4) by the abnormally low or high content of vanillin. 

The following figures show the content of vanillin and coumarin in 
a few typical cheap " vanilla " extracts, selected from a large number 
examined by the author. All of these were entirely artificial, and ranged 
from 5 to 20 per cent by weight of alcohol. 

Vanillin, Coumarin, 

Per Cent. Per Cent. 

A 0.040 0.074 

B None 0.172 

C None 0-330 

D 0.250 None 

E., 0.025 0.144 

As a rule these cheap artificial preparations possess considerable body 
and flavor, but the latter is of a much grosser nature than the genuine 
vaniUa extract, with the delicate and refined flavor of which they are not 
to be mistaken by any one at all familiar with both varieties. 

Winton and Bailey* have found as high as 2.55% of vanillin in 
imitation extracts. They also have detected the presence of acetanihde 
in amounts varying up to 0.15%. This substance at one time was 
extensively employed as an adulterant of vanillin, hence its presence in 
imitation extracts prepared from such vanillin. It is not only worthless 
as a flavor, but is a menace to health. 

* Conn. Agric. Exp. Sta., Rep. 1905, p. 131. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 919 

In the limits of composition for standard vanilla extract given on page 
915, the range in vanilla content is from o.ii to 0.31%. 

METHODS OF ANALYSIS OF VANILLA EXTRACT 

Detection of Artificial Extracts. — The presence of coumarin or Tonka 
tincture to any appreciable extent in vanilla extract is usually recognizable 
by the odor, to one skilled in examining these flavors. The odor of cou- 
marin is more pungent and penetrating than that of vanillin, and in mix- 
tures is apt to predominate over the milder and more delicate odor of 
vanillin. 

Add normal acetate of lead solution to a suspected extract. The 
absence of a precipitate is conclusive evidence that it is artificial. If 
a precipitate is formed, much information may be gained by its character. 
A pure vanilla extract should yield with lead acetate a heavy precipitate, 
due to the various extractives. The precipitate should settle in a few 
minutes, leaving a clear, supernatant, partially decolorized liquid. If 
only a mere cloudiness is formed, this may be due to the caramel present, 
and in any event is suspicious. 

Examination of the Resins. — Resin is present in vanilla beans to the 
extent of from 4 to 11 per cent, and the manufacturer of high-grade 
essences endeavors to extract as much as possible of this in his product. 
This he can do by the use of 50% alcohol, in which all the resin is readily 
soluble, or by employing less alcohol and relying on the use of alkali 
to dissolve it. A pure extract free from alkali should produce a precip- 
itate, when a portion of the original sample is diluted with twice its volume 
of water and shaken in a test-tube. 

When, moreover, the alcohol is removed from such an extract, the 
excess of resin is naturally precipitated. 

The character of the resins extracted from the vanilla bean is so dif- 
ferent from that of other resins as to furnish conclusive tests, worked 
out by Hess * as follows: 25 to 50 cc. of the extract are de-alcoholized by 
heating in an evaporating- dish on the water-bath to about one-third its 
volume. Make up to the original volume with water, and, if no alkali 
has been used in the manufacture of the preparation, the resin will be in 
the form of a brown, flocculent precipitate. To entirely set free the resin, 
acidify, after cooling, with dilute hydrochloric acid, and allow to stand 
till all the resin has settled out, leaving a clear supernatant liquid. The 
resin may be quantitatively determined, if desired, by filtering, wash- 

, * jour. Am. Chem. Soc, 21 (1899), p, 72.1, 



920 FOOD INSPECTION AND ANALYSIS. 

ing, diying, and weighing, but in this case should stand for a long time 
before filtering. 

The resin is collected on a filter, washed, and subjected to various 
tests. A piece of the filter with the attached resin is placed in a beaker, 
containing 'dilute potassium hydroxide. Pure vanilla resin dissolves 
to a deep-red color, and is reprecipitated on acidifying with hydrochloric 
acid. Dissolve another portion of the precipitate in alcohol, and divids 
the alcoholic solution into two portions, to one of which add a few drops 
of ferric chloride, and to the other hydrochloric acid. Pure vanilla resin 
shows no marked coloration in either case, but foreign resins nearly all 
give color reactions under these conditions. 

Tannin. — Test a portion of the filtrate from the resin for tannin by 
the addition of a few drops of a solution of gelatin. A small quantity 
of tannin only should be indicated, if the extract is pure, a large excess 
tending to show added tannin. 

Determination of Vanillin and Coumarin. — Modified Hess and Prescott 
Method. — This process, in its original form devised by Hess and Prescott,* 
has been modified by Winton, collaborating with Silverman, f Bailey,J 
Lott,§, and Berry, || in order to prevent loss of coumarin, detect the 
presence of acetanilide, and permit the determination of normal lead 
number in the same weighed portion. It depends on the principle that 
ammonia water, acting on the ether solution of vanillin and coumarin, 
forms with^ the aldehyde vanillin a compound soluble in water, but 
does not affect the coumarin, which remains in solution in the 
ether. 

"Weigh 50 grams of the extract directly into a tared 250-cc. beaker 
with marks showing volumes of 80 and 50 cc, dilute to 80 cc, and evapo- 
rate to 50 cc. in a water-bath kept at 70° C. Dilute again to 80 cc. with 
water and evaporate to 50 cc. Transfer to a loo-cc. flask, rinsing the 
beaker with hot water, add 25 cc. of standard lead acetate solution 
(80 grams of C. P. crystallized lead acetate, made up to one liter), make 
up to the mark with water, shake, and allow to stand eighteen hours at a 
temperature of from 37° to 40° C, in a bacteriological incubator, in- a 
water-bath provided with a thermostat, or in any other suitable apparatus. 

* Jour. Am. Chem. Soc, 21, 1899, p. 256. 

t Ibid., 24, 1902, p. 1128. 

X Ibid., 27, 1905, p. 719. 

§ A. O. A. C. Proc. 1909, U. S. Dept. of Agric, Bur. of Chem., Bui. 132, p. 109. 

II U. S. Dept. of Agric, Bur. of Chem., Circ. 66. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 921 

Filter through a small dry filter and pipette off 50 cc. of the filtrate into 
a separatory funnel. 

If a determination of normal lead number is desired, pipette off 10 cc. 
of the filtrate into a beaker, and proceed as described on page 925. In 
the latter case, the water used throughout the process should be boiled 
until free from carbon dioxide. If coloring with caramel is suspected 
determine the color value of the original extract and the filtrate (p. 926). 

To the 50 cc. of the filtrate in the separatory funnel, add 20 cc. of ether 
and shake. Draw off carefully the aqueous liquid, together with any 
ether emulsion and then remove the clear ether solution to another sepa- 
ratory funnel. Repeat the shaking of the aqueous liquid with ether 
three times, using 15 cc. each time. 

Shake the combined ether solutions four or five times with 2% ammo- 
nium hydroxide, using 10 cc. for the first shaking and 3 cc. for each 
subsequent shaking. In drawing off the ammoniacal solution, care should 
be taken not to allow any of the ether solution to pass through with it. 
Reserve the ammoniacal solution for the determination of vanillin. 

Transfer the ether solution to a weighed dish and allow the ether 
to evaporate at room temperature. Dry in a sulphuric acid desiccator 
and weigh. If the residue is pure coumarin, it should have a melting- 
point of 67° C, respond to the Leach test, and be completely soluble in 
three or four portions of petroleum ether (boiling-point 30° to 40° C), 
stirring with each portion fifteen minutes. 

If a residue remains in the dish after decanting off the last portion 
of the petroleum ether solution, acetanilide should be looked for (p. 925). 

Add to the ammoniacal solution 10% hydrochloric acid to slightly 
acid reaction. This should be done without delay, as the ammoniacal 
solution on standing grows slowly darker with a loss of vanillin. Cool, 
and shake out in a separatory funnel with four portions of ether, as 
described for the first ether extraction. Evaporate the ether solution at 
room temperature in a weighed dish, dry over sulphuric acid, and weigh. 
The residue should be pure vanillin free from any appreciable amount of 
color and with a melting-point of 80° C. 

If the percentage of vanillin is not desired, and coumarin only is to be 
separated for gravimetric determination, the author has found that good 
results are usually obtained by simply treating the dealcoholized original 
sample with ammonia, extracting it with 3 or 4 portions of chloroform in 
a separatory funnel, and evaporating the combined chloroform extract in 
a tared dish at a temperature not exceeding 60° in the oven. 



922 FOOD INSPECTION AND ANALYSIS. 

Many of the precautions employed in carrying out the above processes 
for vanilHn and coumarin determination may be dispensed with if these 
substances are simply to be tested for qualitatively. 

Determination of Vanillin. — Folin and Denis Method."^— This method 
is based on the fact that vanillin (as well as other mono-, di-, and tri- 
hydric phenol compounds), when treated in an acid solution with phos- 
photungstic-phosphomolybdic acid, gives on addition of an excess of sodium 
carbonate, a beautiful deep blue color. It yields accurate results, requires 
but 5 cc. of the material, and is exceedingly rapid. An analyst familiar 
with the process can make ten or twelve determinations in an hour, whereas, 
working under favorable conditions, he would not be able to make the same 
number of determinations by the Hess and Prescott method in less than 
three days. For inspection purposes the latter method has the advantage 
that the vanillin and coumarin are obtained in crystalline form for sub- 
sequent tests; furthermore coumarin, normal lead number, and color 
value of the lead filtrate are determined in one weighed portion. 

1. Reagents, (a) Standard Vanillin Solution. Dissolve o.i gram 
of pure vanillin in water and make up to i liter. 

(b) Phosphotungstic-phosphomolybdic Acid Reagent. To loo' grams 
of pure sodium tungstate and 20 grams of phosphomolybdic acid (free 
from nitrates and ammonium salts) add ico grams of syrupy phosphoric 
acid (containing 85 per cent H3PO4) and 700 cc. of water. Boil over a 
free flame for one and one-half to two hours, cool, filter, if necessary, and 
make up with water to i liter. An equivalent amount of pure molybdic 
acid may be substituted for the phosphomolybdic acid. 

(c) Sodium Carbonate Solution. Prepare a solution of the c.p. salt, 
saturated at room temperature. 

(d) Lead Solution. Dissolve 50 grams each of basic and neutral lead 
acetate in water and make up to i liter. 

2. Process. Pipette 5 cc. of the extract or substitute into a graduated 
loo-cc. flask, add about 75 cc. of cold tap water and 4 cc. of lead solution, 
make up to the mark with water and shake. Filter rapidly through a folded 
filter paper and pipette 5 cc. of the filtrate, corresponding to 0.25 cc. of the 
extract, into a 50-cc. graduated flask. Into another 50-cc. graduated flask 
pipette 5 cc. of the standard vanillin solution, which volume contains 0.0005 
gram of vanillin. To each flask add from a pipette 5 cc. of the phospho- 
tungstic-phosphomolybdic reagent, directing the stream against the neck 

* Jour. Ind. Eng. Chem., 4, 191 2, p. 670. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 923 

in such a manner as to wash down any adhering vanilHn. Shake the flasks 
by a rotary motion, allow to stand for five minutes, then fill to the mark 
with saturated sodium carbonate solution. Thoroughly mix the con- 
tents of the flask by inverting several times and allow to stand for ten 
minutes in order that the precipitation of sodium phosphate may be com- 
plete. Filter rapidly through folded filters and compare the color of the 
deep-blue solutions, which must be clear, in the colorimeter. 

In this, as in all colorimetric methods, a slight cloudiness of the solution 
of the unknown, by cutting off more light than the standard, gives a low 
reading and correspondingly high result. 

Calculate the grams of vanillin per loo cc. as follows: 

P = ^ = — 

o.2^r 5^ 

in which P is the grams of vanillin per loo cc, R is the reading of the 
standard solution and r is the reading of the unknown solution in the 
colorimeter. 

Estes Method."^— 1. Alcoholic Extracts.— To 5 cc. of the vanilla extract 
in a 50-cc. graduated flask, add 6 cc. of water and 1.5 cc. of acid mercuric 
nitrate reagent, prepared by dissolving metallic mercury in twice its weight 
of concentrated nitric acid (sp.gr. 1.42) and diluting with 25 times its weight 
of water. Make up at the same time a standard solution, using 5 cc. of 
1% aqueous vanillin solution, 6 cc. of water, and 0.5 cc. of the reagent. 
Heat the two flasks in boiling water for twenty minutes, cool rapidly, make 
up to the mark, filter, and compare the intensity of the violet to violet red 
colors formed. 

2. Non-alcoholic Extracts. — Proceed as above except that i.o cc. instead 
of 1.5 of acid mercuric nitrate reagent is used. 

Detection of Coumarin. — Leach Test. — The residue, believed to be 
coumarin, obtained by the Hess and Prescott method, is identified by the 
following test: Add a few drops of water, warm gently, and add to the 
solution a little iodine in potassium iodide. In presence of coumarin a 
brown precipitate will form, which, on stirring with the rod, will soon gather 
in dark-green flecks. The reaction is especially marked if done on a 
white plate or tile. 

Wichmann Test.-\— Dilute 25 cc. of the extract with 25 cc. of water, 
slightly acidify, if alkaline, with sulphuric acid, and distil to dryness. To 

* Jour. Ind. Eng. Chem., g, 191 7, p. 142. 
t U. S. Dept. of Agric, Bur. of Chem., Bui. 95, 1912. 



924 FOOD INSPECTION AND ANALYSIS. 

the distillate, containing the vanillin and coumarin, add 15 to 20 drops of 
I : I potassium hydroxide, hastily evaporate to 5 cc, transfer to a test- 
tube and heat over a free flame until the water completely evaporates and 
the residue fuses to a colorless, or nearly colorless mass. Cool the melt 
and dissolve in a few cubic centimeters of water, transfer to a 50-cc. 
Erlenmeyer flask and acidify slightly with 25% sulphuric acid. Finally 
distil the solution (which should not exceed 10 cc.) into a test-tube contain- 
ing 4 or 5 drops of neutral 0.5% ferric chloride. If coumarin is present 
in the original extract, a purple color will develop, the intensity being 
proportional to the amount of coumarin. 

The Dean Modification * eliminates saccharin and salicylic acid as 
interfering substances in the foregoing test. Dealcoholize 25 cc. of the sam- 
ple or use the residue from the alcohol determination, add 5 cc. of ammonia 
water, and shake with 15 cc. of ether in which vanillin, salicylic acid, and 
saccharin are insoluble in the presence of ammonia, while coumarin is 
readily soluble. Separate the ether layer, evaporate to dryness on a water- 
bath, add 5 drops of 50*^1 potassium hydroxide solution, dry carefully, 
fuse at the lowest possible temperature taking care to avoid blackening. 
Dissolve the mass in a few cc. of water, acidify with dilute sulphuric acid, 
and shake vigorously in a test-tube with 5 cc. of chloroform. Remove 
the chloroform with a small pipette, filter through a small plug of cotton, 
add I to 2 cc. of water containing i to 2 drops ferric chloride solution, 
and shake, noting whether or not a purple coloration is formed. 

Vanillin and Coumarin Crystals under the Microscope. — These sub- 
stances are best examined when crystallized from ether solution, and 
several crystallizations may be found necessary, before the best results 
are obtained. For examination, pour a few drops of the ether solution 
of the purified vanillin or coumarin directly on a slide, and allow to evapo- 
rate spontaneously. Under best conditions vanillin crystallizes from ether 
in long, slender needles, often radiating from central points, or forming 
star-shaped bundles. 

Coumarin crystals are shorter and thicker than vanillin. 

With polarized light pure vanillin crystals give a brilliant play of colors 
between crossed nicols, even without the selenite plate, while pure cou- 
marin ciystals without the selenite are almost lacking in varying colors, and 
show very little play, even when the selenite is employed. This sharp 
distinction is not true when crystallized from chloroform. 

* Jour. Ind. Eng. Chem., 7, 1915, p. 519. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 925 

Determination of Normal Lead NumheT.—Winion and Lott Method.^— 
Mix the lo-cc. aliquot of the filtrate from the lead acetate precipitate, 
obtained in the determination of vanillin and coumarin (p. 921), with 
25 cc. of water, boiled until free from carbon dioxide, and a moderate 
excess of sulphuric acid. Add 100 cc. of 95% alcohol, and mix again. 
Let stand overnight, filter on a Gooch crucible, wash with 95% alcohol, 
dry at a moderate heat, ignite at low redness for three minutes, taking 
care to avoid the reducing flame, and weigh. The normal lead number 
is calculated by the following formula : 

^_ . 00x0.683. (5 -IF) ^^^^^^^^_^^^ 
5 
in which P = normal lead number, 5 = grams of lead sulphate corre- 
sponding to 2.5 cc. of the standard lead acetate solution as determined 
in blank analyses, and W = grams of lead sulphate obtained in 10 cc. of the 
filtrate from the lead acetate precipitate, as above described. 

The standard of the lead acetate solution as determined by blank 
analyses does not change appreciably on standing; it should, however, 
be checked from time to time, especially if the bottle is opened frequently, 
thus permitting absorption of carbon dioxide. In all steps of the process 
only water free from carbon dioxide should be used. 

Pure vanilla extract of standard strength should have a normal lead 
number not less than 0.40. Dilution diminishes the number propor- 
tionately. For example, a mixture containing 50'^ of vanilla extract 
should have a normal lead number not less than 0.20 and so on. 

Determination of Acetanilide.— TFmto« and Bailey Method. — If in the 
determination of vanillin and coumarin (p. 921) a residue is found after 
thoroughly stirring the coumarin with three or four 15-cc. portions of 
petroleum ether and decanting off the liquid; allow this residue to stand 
at room temperature until apparently dry and finish drying in a sul- 
phuric acid desiccator. Weigh and deduct the weight from that previously 
obtained, thus obtaining the true amount of coumarin. 

The residue, if acetanilide, should melt at 112° C. and respond to 
Ritsert's tests as given below. 

If aeetanilide is found in the coumarin it will also be present in the 
vanillin, although in smaller amount. Dissolve the weighed residue of 
impure vanillin in 15 cc. of 10% ammonium hydroxide solution, shake 
twice with ether, evaporate the ether solution at room temperature, dry 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 132, 1910, p. 109; Circ. 66. 



926 FOOD INSPECTION AND ANALYSIS. 

in a sulphuric acid desiccator, and weigh. Deduct this weight from the 
weight of impure vanillin, thus correcting for the amount of acetanilide 
present. 

The total weight of acetanilide is found by adding the weight of the 
portion separated from the coumarin to that separated from the vanillin. 

Ritsert's Tests for Acetanilide.* — Boil the acetanilide, obtained as 
described above, in a small beaker for two or three minutes with 2 to 3 cc. 
of concentrated hydrochloric acid, cool, divide into three portions, and 
test in small tubes (4 to 5 mm. inside diameter), or by spotting on a porce- 
lain plate, as follows: 

(i) To one portion add carefully i to 3 drops of a solution of chlorinated 
lime (i : 200) in such a manner that the two solutions do not mix. A 
beautiful blue color formed at the juncture of the two liquids indicates 
acetanilide. 

(2) To another portion add a small drop of potassium permanganate 
solution. A clear green color is formed if any appreciable amount of 
acetanilide is present. 

(3) Mix the third portion with a small drop of 3% chromic acid solu- 
tion. Acetanilide gives a yellow-green solution, changing to dark green on 
standing five minutes, and forming a dark blue precipitate on addition of 
a drop of caustic potash solution. 

These tests are conclusive only when taken in conjunction with the 
melting-point. 

Determination of Glycerol. — The presence of any considerable quantity 
of glycerol is apparent by the character of the residue obtained on evapora- 
ting 5 grams to dryness, in the determination of total solids. The residue, 
if glycerol is present in notable amount, appears of a moist consistency, 
even when a practically constant weight has been attained at 100° C. 

To determine glycerol, proceed as with wines (page 734). 

Determination of Alcohol. — Measure out 25 cc. of the sample, dilute 
to 50 cc. with water, and distil off about 20 cc. into a 25-cc. graduated 
receiver. Make up to the mark with water, determine the specific gravity 
at 15.6°, and find from the alcohol table the per cent corresponding. 

Cane Sugar and Glucose are determined as in the case of preserves 
and jellies. 

Detection of Caramel. — Lead Acetate Method. — Dealcoholize, precipi- 
tate with lead acetate, and filter, as described for the determination of 
vanillin and coumarin (page 920). If the extract is pure, the filrate will 

* Pharm. Ztg., 2,2,, 188S, p. 383. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 927 

be light yellow; if colored with caramel, the filtrate will be yellow brown 
or deep brown, according to the amount present. 

More definite conclusions may be reached by determining the color 
values of the original extract and the lead acetate filtrate in terms of 
yellow and red of the Lovibond scale and calculating the ratio of the 
two colors, also the percentage of each color remaining in the filtrate. 
The reading of the extract is made in the i-inch cell after diluting 2 cc. to 
50 cc. with 50% alcohol, while that of the filtrate is made directly in a i-inch 
cell or, if very dark in i- or ^-inch cell. 

Color Insoluble in Amyl Alcohol. — Evaporate 25 cc. of the extract on 
a water-bath until no odor of alcohol is apparent and the liquid is reduced 
to a thick sirup, then proceed as described on page 785. 

Determination of Acidity. — Total. — Dilute 10 cc. of the extract to 200 cc. 
and titrate with N/io alkali, using phenolphthalein as indicator. Calcu- 
late to 100 cc. of extract. 

Vanillin Acidity. — Multiply the percentage of vanillin by C5.8. 

Determination of Ash. — Total. — Evaporate 10 cc. of the extract in a 
platinum dish and burn below redness. 

Solubility and Alkalinity of Ash. — See page 657. 

Coal-tar Colors are detected by the usual tests (pages 840 to 875). 

LEMON EXTRACT. 

Spirit or essence of lemon of the National Formulary and former 
editions of the Pharmacopoeia, is a 5% solution (by volume) of lemon 
oil in deodorized alcohol, colored with lemon peel. 

This preparation was dropped from the eighth revision of the Phar- 
macopoeia, and Tinctura limonis corticis or tincture of lemon peel added. 
The following are the directions for the preparation of the latter as given 
in the ninth revision : 

Lemon peel, grated from the fresh fruit 500 grams 

To make 1000 mils 

Prepare a tincture by type process ilf , macerating the drug in 1000 mils 
of alcohol and completing the preparation with alcohol. Use purified 
cotton as a filtering medium. 

U. S. Standards. — Lemon Extract is the flavoring extract prepared 
from oil of lemon, or from lemon peel, or both, and contains not less than 
5% by volume of oil of lemon. 



928 FOOD INSPECTION AND ANALYSIS. 

Oil of Lemon is the volatile oil obtained, by expression or alcoholic 
solution, from the fresh peel of the lemon {Citrus limonum L.), has an 
optical rotation (25° C.) of not less than +60° in a loo-mm. tube, and 
contains not less than 4% by weight of citral. 

Terpendess Extract of Lemon is the flavoring extract prepared by 
shaking oil of lemon with dilute alcohol, or by dissolving terpeneless oil 
of lemon in dilute alcohol, and contains not less than 0.2% by weight 
of citral derived from oil of lemon. 

Terpeneless Oil of Lemon is oil of lemon from which all or nearly 
all of the terpenes have been removed. 

The U. S. standard for lemon extract (5% of lemon oil by volume) 
is a fair one. In fact there are commercial extracts on the market 
containing as high as 12%. An extract of lemon to contain 5% of 
lemon oil must contain at least 80% by volume of alcohol, lemon oil 
being insoluble in dilute alcohol. Deodorized, or puriiied alcohol, com- 
monly known as cologne spirits or perfumers' alcohol, is used in the 
highest-grade preparations, since the odor of ordinary commercial alcohol 
produces a slightly deleterious effect. 

Adulteration of Lemon Extracts. — For making a cheap extract the 
cost of the lemon oil is not so important an item as that of the alcohol, 
and as little as possible of the latter is employed, though pure oil 
is doubtless used. These terpeneless extracts are made by rubbing 
the oil in carbonate of magnesia in a mortar, stirring in slowly a 
little strong alcohol, and allowing the mixture to soak for some 
time. A varying amount of water is added a little at a time, and 
the whole is shaken and again allowed to stand, sometimes for a week, 
before filtering. Finally the extract is filtered, and the coloring matter 
added, consisting sometimes of turmeric tincture and sometimes of coal- 
tar dyes. In these cheap extracts the per cent of alcohol often runs 
below 40, and as little as 4.5% by volume of alcohol has been found 
by the author in a commercial extract. With less than 45% of alcohol 
by volume, no appreciable amount of oil is dissolved, only a portion 
of citral, though such preparations are sometimes bottled as " pure 
extract of lemon." Time and again manufacturers have protested to 
the author that the purest oil was used by them, when notified that their 
brand contained no oil, or when prosecuted in court, and were with 
difficulty convinced that the trouble with their goods was that, on account 
of weak alcohol employed, the lemon oil used failed to get into the final 
product. It is true that a certain taste or odor of the lemon is present, 
even in cheap varieties wherein no oil is found, due to the fact that 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 929 

even dilute alcohol, when slowly percolating through the magnesia in 
which the oil is finely distributed, does abstract therefrom a certam 
amount of citral, which is, however, but a mere shadow of the sub- 
stance and body possessed by a strong alcoholic solution of oil of 
lemon. 

In many instances, where formulas appear stating the name and 
per cent of ingredients, these formulas are entirely deceptive and mis- 
leading, in that the statements are not borne out on analysis. 

The flavor of the cheap extracts is sometimes reinforced by the 
addition of such substances as citral, oil of citronella, and oil of lemon- 
grass, but minute quantities only of these pungent materials can be used, 
not exceeding /o.33% in the case of citral, ando.i% in the case of the 
two last mentioned oils. Cane sugar and glycerin are sometimes 
found. 

U. S. P. tincture of lemon peel owes its color to natural substances 
extracted by the alcohol. This color, however, readily fades on exposure 
to light. Other coloring matters employed are largely coal-tar dyes, 
and occasionally tincture of turmeric or saffron. 

During 1901 practically all the brands of lemon extract sold in Massa- 
chusetts were collected and analyzed. 167 samples were examined, 
representing about 100 brands, and 139 samples were classed as adul- 
terated, based on 5% lemon oil as a standard, and depending on whether 
or not the contents conformed to the labels on the bottles. 

The typical analyses, given in tables on page 930, are selected from the 
tabulated results of the above examination.* 

Forty-two samples contained no lemon oil, ranging in content of 
alcohol from 4% to 45%. 

METHODS OF ANALYSIS OF LEMON EXTRACT. 

A. S. Mitchell was the earliest among food chemists to systematically 
examine lemon extract, and to him are due the methods for determining 
oil of lemon, as well as various other tests now adopted provisionally by 
the A. O. A. Ct 

Detection of Lemon Oil in Alcoholic Lemon Extract. — If on adding 
a large excess of water to the extract no cloudiness occurs, the oil may 



*An. Rep. Mass. State Board of Health, 1901, p. 459; Food and Drug Reprint, p. 41. 
t Jour. Am. Chem. See, 21, 1899, p. 1132; U. S. Dept, of Agric, Bur. of Chera., Bui. 65, 
p. 73; Bui. 107 (rev.), p 159. 



930 



FOOD INSPECTION AND ANALYSIS. 



LEMON EXTRACTS OF STANDARD QUALITY. 



Polarization 


Lemon Oil, 


Specific 


Alcohol, 




in 2oo-mni. 


Per Cent by 


Gravity at 


Per Cent by 


Foreign Ingredients. 


Tube. 


Volume. 


15.6° C. 


Volume. 




30.8 


9.1 


0.8280 


84-39 


Turmeric 


26.0 


7.6 


0.8402 


80.49 




23-5 


6.9 


0.8352 


81.74 


Dinitrocresol 


21.8 


6.4 


0.8396 


82.88 




20.0 


5-9 


0.8335 


84.24 




18.0 


5-3 


0.8268 


86.82 




17.0 


5-0 


0.8496 


80.06 





INFERIOR OR ADULTERATED LEMON EXTRACTS. 



Polarization 


Lemon Oil, 


Specific 


Alcohol, 




in 200-mm. 


1 er Cent by 


Gravity at 


Per Cent by 


Foreign Ingredients. 


Tube. 


Volume. 


15.6° C. 


Volume. 




14.0 


4-1 


0.8592 


77.62 


Dinitrocresol 


12.2 


3-6 


0.8644 


76.08 


< ( 


II. 


3-1 


0.8620 


77-50 


A coal-tar dye 


9-9 


2-9 


0.8615 


77-90 




8.0 


2-3 


0.8531 


81.61 


Dinitrocresol 


6.8 


2.0 


0.8416 


87-55 


Tropffiolin 


5-0 


i-S 


0.8832 


71. 10 


< c 


3-5 


I.O 


0.8939 


67.68 




2.8 


0.8 


0.8995 


65-23 


Dinitrocresol 


2.2 


0.6 


0.8941 


67.69 


" 


1-4 


0.4 


0.9136 


59-40 


A nitro dye 


0-3 


O.I 


0.9408 


46.40 


Dinitrocresol 


0.0 


0.0 


0-9937 


4-49 


Tropseolin 


-8.0 


0.0 






Invert sugar 


27.0 


0.0 




27.49 


Cane sugar 


0.0 


0.0 




47-35 


Oil other than lemon 



fairly be inferred to be absent. The degree of cloudiness produced is 
proportional to the amount of lemon oil present. 

Determination of Lemon Oil in Alcoholic Lemon Extract. — Mitchell 
Polarization Method. — Polarize the undiluted extract in a 200-mm. tube at 
20° C. Divide the reading on the Ventzke scale by 3.4, and if cane sugar 
or other optically active substances are absent, the quotient expresses the 
per cent of lemon oil by volume. With instruments reading in circular 
degrees, divide the rotation in minutes at 20° C. by 62,5, If the Laurent 
instrument with sugar-scale is used, divide the sugar-scale reading by 4.8. 

Cane sugar, though rarely found in lemon extract, is occasionally 
used in small amount. It is said to aid in the solution of the oil. If it 
is present, wash the solid residue from 10 cc. of the sample (dried on 
a water-bath) with three portions of 5 cc. each of ether, to remove waxy 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 931 

and fatty matters, dry and weigh the residue of cane sugar, deducting 
0.38 from the reading for each o.i^c of sugar so found. 

Mitchell Precipitation Method. — Pipette 20 cc. of the extract into a 
Babcock milk-flask, add i cc. of dilute hydrochloric acid (i : i); add 
25 to 28 cc. of water previously warmed to 60° C; mix, and stand in 
water at 60° for five minutes; whirl in a centrifuge for five minutes; fill 
with warm water to bring the oil into the graduated neck of the flask, 
and repeat the whirling for two minutes; stand in water at 60° for a few 
minutes, and read the per cent of oil by volume. WTiere the oil of lemon is 
present in amounts over 2%, add to the percentage of oil found 0.4% 
to correct for the oil retained in solution. Where less than 2% and more 
than 1% is present, add 0.3% for correction. 

Save the precipitated oil for the determination of refraction. 

When the extract is made in accordance with the U. S. Pharma- 
copoeia, the results by the two methods just given should agree within 
0.2%. 

To obtain per cent by weight from per cent by volume, as found 
by either of the above methods, multiply the volume percentage by 
0.86, and divide the rei:ult by the specific gravity of the original ex- 
tract. 

Howard's Modification of MitchelVs Precipitation Method.^ — Pipette 
10 cc. of the extract in a Babcock milk bottle, and add in the following 
order, 25 cc. of cold water, i cc. hydrochloric acid (specific gravity 1.2), 
and 0.5 cc. chloroform. Close the mouth of the bottle with the thumb, 
and shake vigorously for not less than one minute. Whirl the bottle 
in a centrifuge for one and one-half to two minutes, thus forcing the chloro- 
form and oil to the bottom of the bottle, and remove all but 3 or 4 cc. cf 
the clear supernatant liquid by means of a glass tube of small bore 
connected with an aspirator. 

To the residue add i cc. of ether, agitate thoroughly, plunge the 
bottle to the neck in a boiling-water bath, holding at slight angle, and 
rotate in the bath for exactly one minute. This step is best carried out 
by removing one of the small rings from a water- or steam-bath and 
holding the bottle in the live steam. The ether serves the purpose 
of steadily and rapidly sweeping out every trace of chloroform with- 
out appreciable loss of oil. Finally, cool the bottle, fill nearly to 

* Jour. Am. Chem. Soc, 30, 1908, p. 608. 



932 FOOD INSPECTION AND ANALYSIS. 

the top of the neck with water at room temperature, centrifuge for one- 
half minute, read the column of separated oil to the top meniscus, and 
multiply the reading by two, thus obtaining the per cent of oil. 

This method may also be used for determining the oil in extracts of 
orange, peppermint, clove, cinnamon, and cassia, employing in the case of 
the heavier oils dilute sulphuric acid (i : 2), instead of water, in filling 
the bottles before the last centrifuging. 

Determination of Lemon Oil in Non-alcoholic Lemon Extract. — The 
following methods are applicable to extracts consisting of emulsions of 
lemon and other essential oils in mucilage of acacia, tragacanth, karaya, 
or other gums with or without glycerol. 

Boyles Precipitation Method.^ — Measure 10 cc. of the emulsion into 
a graduated cylinder, transfer as much as possible to a 50-cc. flask, rinse 
the cylinder with lo-cc. portions of 95% alcohol, and with the aid of a 
glass rod transfer all of the emulsion and precipitated gum to the flask. Fill 
to the mark, shake thoroughly, and let stand about thirty minutes. Filter 
through a folded filter and determine the oil in a 20-cc. portion of the 
filtrate as in alcoholic extracts. Multiply the per cent of oil found in the 
filtrate by five to obtain the per cent of oil in the original emulsion. The 
method is applicable also to orange, almond, anise, and nutmeg extracts of 
the non-alcoholic type. 

Boyles Distillation Method.^ — Measure 10 cc. of the extract into a 
graduated cylinder and transfer it by means of about 35 cc. of water to a 
side-neck distilling flask and distil with steam into a ico-cc. cassia flask. 
Since only 95% of the oil is recovered the amount found must be multiplied 
by 100 and divided by 95. 

The method is also applicable to non-alcoholic orange and peppermint 
extracts, in the latter case the amount recovered is divided by 90 instead 
of 95. 

Determination of Alcohol. -Mitchell has shown that the difference 
in specific gravity between oil of lemon and stronger alcohol is not so 
great, but that a very close approximation to the true percentage of alcohol 
in lemon extracts may be obtained from the specific gravity itself, assum- 
ing, of course, that foreign substances, such as sugar, glycerol, etc., are 
absent. In the absence of such foreign substances determine the specific 
gravity of the sample, ascertain from the alcohol tables on pages 690 to 
703 the per cent of alcohol by volume corresponding. This gross figure 

* Jour. Ind. Eng. Chem., 10, 1918, p. 537. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 933 

includes the lemon oil, the per cent of which should be deducted for the 
correct per cent of alcohol. 

In the absence of oil of lemon, a measured portion of the original 
sample may be distilled, and the percentage of alcohol determined from 
the distillate in the usual manner, but when lemon oil is present, this 
should first be removed by diluting 50 cc. of the extract with water to 
200 cc. exclusive of the oil In the sample, and shaking the mixture with 
5 grams of magnesium carbonate in a flask, filtering through a dry filter, 
and determining the alcohol by distillation in a portion of the filtrate. 
The result is multiplied by four to correct for the dilution. 

Determination of Total Aldehydes. — Chace's Method* — i. Reagents. 
■ — (a) Aldehyde-free Alcohol. — Allow alcohol (95% by vol.) containing 
5 grams of metaphenylene diamine hydrochloride per liter to stand for 
twenty-four hours with frequent shaking. Previous treatment with 
potassium hydroxide is unnecessary. Boil under a reflux cooler for at 
least eight hours, allow to stand overnight and distil, rejecting the 
first 10 and the last 5 per cent which come over. Store in a dark, 
cool place in well-filled bottles. Twenty-five cc. of this alcohol, on stand- 
ing for twenty minutes in the cooling bath with the fuchsin solution 
(20 cc), should develop only a faint pink coloration. If a stronger 
color is developed, treat again with metaphenylene diamine hydro- 
chloride. 

(b) Fuchsin Solution. — Dissolve 0.5 gram of fuchsin in 250 cc. of 
water, add an aqueous solution of sulphur dioxide containing 16 grams 
of the gas, and allow to stand until colorless, then make up to i hter 
with distilled water. This solution should stand twelve hours before 
using, and should be discarded after three days. 

(c) Standard Citral Solution. — Use i mg. of c. p. citral per cc. in 
50% by volume aldehyde-free alcohol. This solution deteriorates on 
standing, and should not be kept over three or four days, 

2. Apparatus. — {a) A Cooling Bath. — Keep at from 14 to 16° C. 
The aldehyde-free alcohol, fuchsin solution, and comparison tubes are 
to be kept in this bath. 

(6) Colorimeter. — Any form of colorimeter, using a large volume of 
solution and adapted to rapid manipulation, may be used. 

The comparison may also be made in Nessler or Hehner tubes. 

* Jour. Am. Chem. Soc, 28, 1906, p. 1472. U. S. Dept. of Agric, Bur. of Chem., Bui. 
122, p. 32. 



934 FOOD INSPECTION AND ANALYSIS. 

3. Manipulation. — Weigh in a stoppered weighing flask approxi- 
mately 25 grams of extract, transfer to a 50-cc. flask, and make up to 
the mark at room temperature with aldehyde-free alcohol. Measure at 
room temperature and transfer to a comparison tube 2 cc. of this solution. 
Add 25 cc. of the aldehyde-free alcohol (previously cooled in a bath), 
then 20 cc. of the fuchsin solution (also cooled), and finally make up to 
the 50-cc. mark with more aldehyde-free alcohol. Mix thoroughly, stopper, 
and place in the cooling bath for fifteen minutes. Prepare a standard 
for comparison at the same time and in the same manner, using 2 cc. of 
the standard citral solution. Remove and compare the colors developed. 
Calculate the amount of citral present and repeat the determination, 
using a quantity sufficient to give the sample approximately the strength 
of the standard. From this result calculate the amount of citral in the 
sample. If the comparisons are made in Nessler tubes, standards con- 
taining I, 1.5, 2, 2.5, 3, 3.5, and 4 mg. should be prepared, and the trial 
comparison made against these, the final comparison being made with 
standards between 1.5 and 2.5 mg., varying but 0.25 mg. 

It is absolutely essential to keep the reagents and comparison tubes 
at the required temperature. Comparisons should be made within one 
minute after removing the tubes from the bath. Where the comparisons 
are made in the bath (this being possible only where the bath is glass), 
the standards should be discarded within twenty-five minutes after 
adding the fuchsin solution. Give samples and standards identical 
treatment. 

Determination of Citral. — Hiltner's Method."^ — i. Reagents. — (a) 
Metaphenylene Diamine Hydrochloride Solution. — Prepare a 1% solution 
in 50% ethyl alcohol. Decolorize by shaking with fuller's earth or animal 
charcoal, and filter through a double filter. The solution should be 
bright and clear, free from suspended matter and practically colorless. 
It is well to prepare only enough solution for the day's work, as it darkens 
on standing. The color may be removed from old solutions by shaking 
again with fuller's earth. 

{b) Standard Citral Solution. — Dissolve 0.250 gram of c. p. citral 
in 50% ethyl alcohol and make up the solution to 250 cc. 

(c) Alcohol. — For the analysis of lemon extracts, 90 to 95 per cent 
alcohol should be used, but for terpeneless extracts alcohol of 40 to 50 
per cent strength is sufficient. Filter to remove any suspended mat- 

* Jour. Ind. Eng. Chem., i, 1909, p. 798. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 935 

ter. The alcohol need not be purified from aldehyde. If not prac- 
tically colorless, render slightly alkaline with sodium hydroxide and 
distil. 

2. Apparatus. — The Schreiner colorimeter (page 66) or Eggertz 
tubes may be used. With this latter apparatus, alcohol is added, small 
quantities at a time, to the stronger colored solution until after shaking 
and viewing transversely, the colors in the two tubes are exactly matched. 
Calculations are then made by estabhshing a proportion between the 
volumes of samples taken and the final dilutions. 

3. Manipulation. — All of the operations may be carried on at room 
temperature. Weigh into a 50-cc. graduated flask 25 grams of the 
extract, and make up to the mark with alcohol (90-95 per cent). Stopper 
the flask and mix the contents thoroughly. Pipette into the colorimeter 
tube 2 cc. of this solution, add 10 cc. of metaphenylene diamine hydro- 
chloride reagent, and complete the volume to 50 cc. (or other standard 
volume) with alcohol. Compare at once the color with that of the 
standard, which should be prepared at the same time, using 2 cc. of 
standard citral solution and 10 cc. of the metaphenylene diamine reagent, 
and making up to standard volume with alcohol. From the result of 
this first determination, calculate the amount of standard citral solution 
that should be used in order to give approximately the same citral 
strength of the sample under examination, then repeat the determination. 

Methyl Alcohol has been used by unscrupulous manufacturers in 
lemon extracts. It is detected and determined by the refractometer 
method of Leach and Lythgoe (page 781). 

As a confirmatory test for methyl alcohol the distillate, after testing 
by the Leach and Lythgoe method, may to advantage be subjected to 
the method of IMuUiken and Scudder,* which depends on the conversion 
of the methyl alcohol to formaldehyde. The latter method is also useful 
cs a rough prehminary test on the original extract without distillation, 
the extract, being, however, first diluted until the liquid contains approxi- 
mately 12% by weight of alcohol, shaking with magnesium carbonate, 
and filtering when lemon oil is present. 

Oxidize 10 cc. of the liquid in a test-tube as follows: Wind copper 
wire I mm. thick upon a rod or pencil 7 to 8 mm. thick, in such a manner 
as to inclose the fixed end of the wire, and to form a close coil 3 to 3.5 cm. 
long. Twist the two ends of the wire into a stem 20 cm. long, and bend 



*Amer. Chem. Jour., 23, 1899, p. 266. 



936 FOOD INSPECTION AND ANALYSIS. 

the stem at right angles about 6 cm. from the free end, or so that the 
coil may be plunged to the bottom of a test-tube, preferably about i6 mm. 
wide and i6 cm. long. Heat the coil in the upper or oxidizing flame of 
a Bunsen burner to a red heat throughout. Plunge the heated coil to 
the bottom of the test-tube containing the diluted alcohol. Withdraw 
the coil after a second's time and dip it in water. Repeat the operation 
from three to five times, or until the film of copper oxide ceases to be 
reduced. Cool the liquid in the test-tube meanwhile by immersion in 
cold water. 

Test for Formaldehyde. — Divide the oxidized liquid in the test-tube 
into two parts, testing one for formaldehyde with pure milk by the 
hydrochloric acid and ferric chloride test. Test the other portion by 
the resorcinol test for formaldehyde, page 882, avoiding an excess of the 
reagent.* 

Tests for Colors. — Evaporate a portion of the sample to dryness, 
dissolve the residue in water, and extract coal-tar colors if present by 
Arata's method, page 841, or with hydrochloric acid. 

Much information may often be gained by treatment of the original 
extract with strong hydrochloric acid. If the color employed be turmeric, 
no change in color will be evident on addition of the acid. If tropoeolin 
or methyl orange is present, the solution will turn pink, while partial 
decoloration of the solution indicates naphthol yellow S, and complete 
decoloration shows presence of dinitrocresols or naphthol yellow. 

Test for turmeric by boric acid, page 821. 

Detection of Lemon and Orange Peel Coloring Matter. — Alhrech 
Method.^ — Place a few cubic centimeters of the extract in a test-tube 
and add slowly 3 or 4 volumes of concentrated hydrochloric acid. Place 
a few cubic centimeters of the extract in a second tube and add several 
drops of concentrated ammonia. In the presence of lemon or orange 
peel color the yellow tint of the original extract will be materially deep- 
ened in both cases. 

Determination of Total Solids and Ash. — Total Solids are estimated 
by evaporating on the water-bath 10 grams of the sample in a tared dish, 
and drying at 100° to constant weight. If glycerol be present, it is dif- 
ficult if not impossible to get a constant weight. Cane sugar and glycerol, 
if present, will be apparent in the residue. If capsicin has been used, it 
will be noticed by the taste. 

* Amer. Chem. Jour., 24, 1900, p. 451. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 71. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 



937 



Burn to an ash the residue from the soHds in a muffle at a low red 
heat, cool in a desiccator, and weigh. 

Glycerol is determined as in wine, page 734. 

Detection of Tartaric or Citric Acid. — To a portion of the extract 
in a test-lube add an equal volume of water to precipitate the oil. Filter 
and add one or two drops of the filtrate to a test-tube half full of cold, 
clear lime water. If tartaric acid is present, a precipitate will come 
down, which is soluble in an excess of ammonium chloride or acetic acid. 

Filter off the precipitate, or, if no precipitate is visible, heat the con- 
tents of the tube. Citric acid will precipitate in a large excess of hot 
lime water. 

Examination of Lemon Oil. — The oil separated from the extract in 
the process of determining the lemon oil by precipitation (p. 931), is 
most readily examined for its purity, after drying with calcium chloride, 
by determination of its specific gravity, its index of refraction, or its 
refractometric reading with the Zeiss butyro-refractometer, and its polari- 
scopic reading. 

The specific gravity and refractometric readings are determined as 
with fixed oils, using with the butyro-refractometer a sodium flame or 
y^ellow bichromate color-screen, which gives perfectly sharp readings 
without dispersion. 

The table given below shows readings on the Zeiss butyro-refractometer 
of pure lemon oil at various temperatures, using the sodium light. 

For examination of high polarizing essential oils like oil of lemon, 
the author employs a 50-mm. tube, in order to get the readings on the 
undiluted oil well within the limits of the cane sugar scale on the polar- 
iscope. If such a tube is not available, dilute the oil with an equal 



READINGS ON 


ZEISS BUTYRO-REFRACTOMETER OF LEMON 


OIL. 


Tempera- 


Scale 


Tempera- 


Scale 


Tempera- 


Scale 


Tempera- 


Scale 


ture, 
Centigrade. 


Reading. 


ture, 
Centigrade. 


Reading. 


ture, 
Centigrade. 


Reading. 


ture, 
1 Centigrade. 


Reading. 


40.0 


59-4 


35-0 


62.8 


30.0 


66.3 


25.0 


69.7 


39-5 


59-7 


34.5 


63.1 


29-5 


66.6 


24-5 


70.0 


39-0 


60.1 


34-0 


63-5 


29.0 


67.0 


24.0 


70.4 


38-5 


60.4 


33-5 


63.8 


28.5 


67-3 


23-5 


70.7 


38.0 


60.8 


33-0 


64.2 


28.0 


67-7 


23.0 


71. 1 


37-5 


61.0 


32-5 


64-5 


27-5 


68.0 


22.5 


71.4 


37-0 


61.5 


32.0 


64.9 


27.0 


68.4 


22.0 


71.8 


36-5 


61.8 


3I-S 


65.1 


26.5 


68.7 


21.5 


72.1 


36.0 


62.1 


31.0 


65.6 


26.0 


69.0 


21,0 


72-5 


35-5 


62.4 


30-5 


65.9 


25-5 


69-3 


20.5 


72.8 


35-0 


62.8 


30.0 


66.3 


25.0 


69.7 


20.0 


73-2 



938 



FOOD INSPECTION AND ANALYSIS. 



volume of alcohol, and use the loo-mm, tube. The table given below 
expresses constants of pure lemon oils and of various commonly employed 
adulterants, as determined in the laboratory of the Massachusetts State 
Board of Health. 



CONSTANTS OF SOME ESSENTIAL OILS. 



Oil 



Butyro-refractometer 
(Sodium Light) at — 


Rotation 
in 100- 
Millimeter 

Tube, 
Ventzke 

Scale. 


Temp. 


Reading. 


25- 

25- 
22-5 


69-5 
71.2 
96.9 


173-0 

184.5 

-10.8 


22.5 


87.1 


— 10.2 


23- 


87.9 


— 22.0 


23- 


91.0 


-5-6 


22.5 


95-0 


-3-6 



Specific 

Gravity 

at 15.6° C. 



Oil of lemon (lowest) , 

'• " " (highest) , 

" " '• grass (A. Giese) , 

" " citronella (A. Giese) 

Terpeneless oil of lemon (Hansel's) 

" ti it (t grass (Hansel's). 
Citral (A. Giese) 



0.8580 
0.8610 
0.9309 

0-9437 
0.9463 
0.9232 
0.9296 



Oil of Lemon is a light-yellow liquid, having the pleasant odor of 
fresh lemons, and an aromatic, mild, somewhat bitter after taste. It 
is obtained from the grated rind of the lemon either by treatment with 
hot water, skimming off the oil which rises to the surface, or by pressure, 
or by distillation with water. It is rapidly changed by action of air and 
light, becoming "terpeney," and under these conditions its solubility 
in alcohol seems to increase. Its composition is somewhat uncertain, 
but according to Wallach * nearly 90% consists of hydrocarbons, mostly 
terpenes, the most important of -hich is the terpene limonene f of the 
dextro-gyrate variety, also known as citrene. 

Another important constituent of lemon oil is the aldehyde citral, 
present to the extent of from 4 to 5 per cent. To this the odor of the 
oil is largely due. A second aldehyde, citronellal, is also present. 

A frequent adulterant of lemon oil is turpentine oil, which lowers 
the rotation considerably, and is thus most easily rendered apparent. 

Chace J detects small quantities of turpentine by the difference in 
crystalline form of pinene nitroso-chloride from that of limonene nitroso- 
chloride. 

Citral (CioH,gO) is an aldehyde present in lemon oil and in oil of 
lemon-grass, and, while it may be separated from these oils, is prepared 



* Liebig's Annalen, 227, p. 290. 

t There are two limonenes, one of which is dextro- and the other laevo-rotary. 
two are completely alike in their behavior, differing only in their optical rotation. 
t Jour. Am. Chem. Soc, 30, 1908, p. 1475. 



The 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 939 

artificially by oxidizing geraniol with chromic acid.* It is a mobile oil, 
and when perfectly pure is optically inactive. The commercial citral is, 
however, slightly laevo-rotary, due no doubt to impurities. 

Oil of Lemon-grass is distilled from lemon-grass, Andropogon citratus 
(D. C), cultivated in India. It is reddish yellow in color, and has an 
intense lemon-Uke odor and taste. Very little is known of its composi- 
tion, but it seems to contain several aldehydes, one of which is citro- 
nellal, and another citral. The latter, however, is its chief constituent, 
being present to the extent of 70 to 75 per cent. 

Citronellal (CioHigO) is an aldehyde found in various oils, especially 
in citronella oil, from which it is readily separated. It is made artificially 
by the oxidation of the primary alcohol citronellol (QoHjoO). It is 
quite strongly dextro-rotary. 

Oil of Citronella is distilled from the grass Andropogon nardus (L.j, 
growing chiefly in Ceylon, India, and tropical East Africa. It is a yel- 
lowish-brown liquid with a pleasant and lasting odor. Citronellal is 
present in this oil to the extent of from 10 to 20 per cent, and the oil 
contains also from 10 to 15 per cent of terpenes, among which are 
camphene. 

Tests for Citral, Citronellal, and Limonene.t— Shake 2 cc. of the 
sample to be examined in a corked test-tube with 5 cc. of a solution of 
10 grams of mercuric sulphate in sufficient 25% sulphuric acid to make 
100 cc. Citral yields a bright-red color, which rapidly disappears, leav- 
ing a whitish compound, which floats on top. Citronellal forms a bright- 
yellow color, remaining for some time. Limonene forms an evanescent, 
faint flesh color, and leaves a white compound. 

METHODS OF ANALYSIS OF LEMON OIL. 

The following are the methods of the A. O. A. C.J They apply to 
orange as well as lemon oil. 

Determination of Specific Gravity. — Determine the specific gravity 
by means of a pycnometer or a Sprengel tube at 15.6° C. 

Determination of Index of Refraction. — Determine the index of refrac- 
tion with any standard instrument, making the reading at 20° C. 

Determination of Rotation. — Determine the rotation at 20° C. with 
any standard instrument using a 50-mm. tube and sodium light. The 

* Tiemann, Berichte, 31, p. 331 1. 

t Burgess, Chem. and Drugg., 57, p. 732. 

X U. S. Dept. of Agric, Bui. 137, 191 1, p. 72. 



940 FOOD INSPECTION AND ANALYSIS. 

results should be stated in angular degrees on a loo-mm. basis. If 
instruments having the sugar scale are used, the reading on orange oils 
is above the range of the scale, but readings may be obtained by the use 
of standard laevo reading quartz plates. 

Determination of Citral. — Kleher Method. — i. Reagents. — (a) Phenyl 
Hydrazin. — A io% solution of the purified chemical in absolute alcohol. 
A sufficiently pure product can be obtained by rectification of the com- 
mercial article, rejecting the first portions coming over which contain 
ammonia. 

ih) Hydrochloric Acid. — A half normal solution. 

2. Manipulation. — Weigh 15 grams of the sample into a small glass- 
stoppered flask; add 10 cc. of the phenyl hydrazin solution. After allow- 
ing to stand for half an hour at room temperature, titrate with half 
normal hydrochloric acid, using either methyl or ethyl orange as indicator. 
Titrate 10 cc. of the phenyl hydrazin reagent in the same manner. The 
difference in cubic centimeters of half normal acids between this titra- 
tion and that of the sample, multiplied by the factor 0.076, gives the 
weight of citral in the sample. 

If difficulty is experienced in detecting the end point of the reaction, 
carry out the titration until the solution is distinctly acid, transfer to 
a separatory funnel, and draw off the alcoholic portion. Wash the oil 
with water, adding the washings to the alcoholic solution, and titrate 
back with half normal alkali, making the necessary corrections. 

Hiltner Method. — Proceed as under lemon extract (p. 934) weighing 
2 grams of the oil, diluting to 100 cc, and using 2 cc. of this solution for 
the comparison. 

Determination of Total Aldehydes. — Proceed as under lemon extract 
(p. 875), using from 2 to 5 grams of the sample in 100 cc. of aldehyde- 
free alcohol. This method should be used on orange oils the aldehydes 
of which are not determined by the other metliods, although valuable 
information as to the content of added citral in the oil can be obtained by 
use of the Hiltner method. 

Determination of Physical Constants of the Ten Per Cent Distillate. 
Schtmmel 6* Co. Method. — Place 50 cc. of the sample in a 3-bulb Laden- 
burg flask in which the main bulb has a diameter of 6 cm, and is of 
200 cc. capacity and which has the condensing bulbs of the following 
dimensions: 5.5 cm., 5 cm., 2.5 cm., and in which the distance from 
the bottom of the flask to the opening of the side arm is 20 cm. Distil 
the oil at the rate of 2 cc. per minute until 5 cc. have been distilled. 

* U. S. Dept. of Agric, BuJ. 137, 191 1, p. 72. 




FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 941 

Determine the refractive index and rotation of this distillate as directed 
above. 

Detection of Pmene.—Chace Method.— ^Mix the io% distillate as 
obtained above with 5 cc. of glacial acetic acid, cool the mixture thoroughly 
in a freezing bath, and add lo cc. of ethyl nitrite; then add slowly, with 
constant shaking, 2 cc. of a mixture of 2 parts concentrated hydrochloric 
acid and i part water which has been previously cooled. Keep this 
mixture in the freezing bath during this operation and allow it to remain 
therein for 15 minutes. Filter off the crystals formed, using vacuum and 
washing with strong alcohol. Return the filtrate and washings to the 
freezing bath and allow them to remain for 15 minutes. Filter off the 
crystals formed, using the original filter-paper. Wash the two crops of 
crystals thoroughly with alcohol. Dry at room temperature and dis- 
solve in the least possible amount of chloroform. Reprecipitate the nitroso- 
chloride crystals with methyl alcohol and mount for examination under 
the microscope with olive oil. Pinene nitroso-chloride crystals have 
irregular pyramidal ends while limonene nitroso-chloride crystallizes in 
needle forms. 

Determination of Alcohol.— The amount of alcohol present in oils 
which have been used for the manufacture of terpeneless extracts may 
be approximately determined by washing repeatedly with small portions 
of saturated sodium chloride solution and determining the alcohol in 
these washings in the usual way. 

ORANGE EXTRACT. 

Orange Oil is a yellowish liquid, having the characteristic odor of 
orange, and a mild aromatic taste. It is prepared from orange peel in 
an analogous manner to that of lemon oil, which it somewhat resembles 
in chemical composition. At least 90% of orange oil, according to 
Walach, consists of dextro-limonene (citrene). It has a much higher 
specific rotatory power than lemon oil. 

U. S. Standards. — Oil of Orange is the volatile oil obtained, by 
expression or alcoholic solution, from the fresh peel of the orange (Citrus 
aurantium L.) and has an optical rotation at 25° C. of not less than 
+ gS° ^^ ^ loo-mm. tube. 

Terpeneless Oil of Orange is oil of orange from which all or nearly 
all of the terpenes have been removed. 

Orange Extract is the flavoring extract prepared from oil of orange, 



942 FOOD INSPECTION AND ANALYSIS. 

or from orange peel, or both, and contains not less than 5% by volume 
of oil of orange. 

Terpeneless Extract of Orange is the flavoring extract prepared by 
shaking oil of orange with dilute alcohol, or by dissolving terpeneless 
oil of orange in dilute alcohol, and corresponds in flavoring strength 
to orange extract. 

Method of Analysis, — Orange oil and orange extract are analyzed by 
the same methods as lemon oil (p. 940) and lemon extract (page 929). 

In the determination of orange oil by Mitchell's polariscopic method 
divide the direct reading on the Ventzke scale, calculated for the 200- mm. 
tube, by 5.3 to obtain the per cent of orange oil by volume. To obtain 
the per cent by weight, multiply the per cent by volume by 0.85 and 
divide by the specific gravity of the extract. 

ALMOND EXTRACT. 

Oil of Bitter Almonds is obtained by distilling crushed bitter almonds, 
peach seeds, or apricot seeds with water. It should be remembered that 
both sweet and bitter almonds yield a bland fixed oil on pressure, which is 
not to be confounded with the volatile oil yielded on distillation of the bitter 
almonds after the fixed oil has been pressed out. Bitter almonds contain 
a glucoside, amygdalin, together with a ferment known as emulsin or 
synaptase, which, acting on the amygdahn in the distillation, produces 
benzaldehyde and hydrocyanic acid as follows: 

C20H27NO11 + 2H2O = C^HgO + HCN 4- aCeHiaOg. 

Amygdalin Benzalde- Hydro- Glucose 

hyde cyanic acid 

The unpurified oil of bitter almonds consists largely of benzaldehyde, 
with a small amount of the poisonous hydrocyanic acid. Nearly all 
of the commerical oil is made from the cheaper apricot and peach seeds 
rather than those of the bitter almond, but the product is practically 
identical. The oil is freed from hydrocyanic acid by agitating with 
calcium hydrate and a solution of ferrous chloride, distilling the mixture, 
and drying the oil which comes over with calcium chloride. 

Benzaldehyde constitutes 90 to 95 per cent of oil of bitter almonds, 
having a bitter, acrid, burning taste, and a marked almond odor. The 
specific gravity of the crude oil varies from 1.052 to 1.082, while that 
of the purified oil (benzaldehyde) at 20° is 1.0455. Its boihng-point is 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 943 

1 80° C. On standing it becomes readily oxidizable to benzoic acid. It 
is readily soluble in alcohol and ether. Its solubility in water is slight, 
1:300. Its index of refraction at 20° C. is 1.5446. It should be noted 
that the refractive indices of almond oil, whether wdth or without hydro- 
cyanic acid, and of artificial benzaldehyde are nearly the same. 

Benzaldehyde is produced artificially in a variety of ways, but is 
chiefly prepared by the action of chlorine on hot toluene. The result- 
ing benzyl chloride is distilled with lead nitrate and water in an atmos- 
phere of carbon dioxide, which forms benzoic aldehyde. Synthetic 
benzaldehyde has the same properties as the purified oil of bitter almonds, 
and has largely displaced it in the market, not the least of its advantages 
being its freedom from hydrocyanic acid. 

Almond Extract. — Essence of bitter almonds, or Spiritus amygdala 
amarcd, is thus prepared according to the U. S. Pharmacopoeia: 

Oil of bitter almonds 10 cc. 

Alcohol 800 cc. 

Distilled water sufficient to make 1000 cc. 

Thus 1% of almond oil is present in the product. 

U. S. Standards. — Oil of Bitter Almonds, commercial, is the volatile 
oil obtained from the seed of the bitter almond {Amygdalus communis 
L.), the apricot {Prunus armeniaca L.), or the peach (Amygdalus persica 
L.). 

Almond Extract is the flavoring extract prepared from oil of bitter 
almonds, free from hydrocyanic acid, and contains not less than 1% 
by volume of oil of bitter almonds. 

Adulteration of Almond Oil. — The official essence of the Pharma- 
copoeia does not specify that the almond oil used be perfectly free from 
hydrocyanic acid, in spite of the fact that its highly poisonous nature is 
well known, and that it exists in the crude oil to the extent of from 4 to 
6 per cent. True, but httle of it is found in the extract, but in these days, 
when the unannounced presence in foods of such substances as antiseptics 
and coloring matters is regarded as questionable from a sanitary stand- 
point, in spite of the fact that their toxic effects on man are still matters 
of controversy, there thould be httle hesitancy in pronouncing the presence 
of prussic acid objectionable, especially when a pure almond oil entirely 
free from it is readily obtainable. 

The presence of nitrobenzol or oil of mirbane as a substitute of 



944 FOOD INSPECTION AND ANALYSIS. 

almond oil is to be looked for. This substance is sometimes, though 
incorrectly, called artificial oil of bitter almonds. It is a heavy, yellow 
liquid of the composition C6H5NO2, readily soluble in water. Its specific 
gravity at 20° C. is 1.2039. Its boiling-point is 205° C. It is formed 
by the action of nitric acid on benzol. It possesses a highly pungent 
odor, somewhat like that of oil of bitter almonds, though more penetra- 
ting and less refined. Its index of refraction at 20° C. is 1.5 5 17. 

METHODS OF ANALYSIS OF ALMOND EXTRACT. 

Determination of Benzaldehyde. — The following methods are appli- 
cable to alcoholic extracts. In the case of non-alcoholic extracts convert 
first into alcoholic extracts as described for lemon extract, page 932. 

Denis and Dunbar Method.^ — i. Reagent. — Mix 30 cc. of glacial 
acetic acid with 40 cc. of water, then pour in 2 cc. of phenyl hydrazine. The 
reagent should be made up immediately before use and discarded when 
more than an hour old. 

2. Method. — Measure out two portions of 10 cc. each of the extract 
into 300-cc. Erlenmeyer flasks and add 10 cc. of the reagent to one flask 
and 15 cc. to the other. Shake, stopper tightly, and allow to stand in a 
dark place overnight. Add 200 cc. of distilled water and filter the pre- 
cipitate of hydrazone on a tared Gooch crucible provided with a thin 
coat of asbestos. Wash first with cold water, finally with 10 cc. of 10% 
alcohol, and dry for three hours in a vacuum-oven at 70° C, or to con- 
stant weight over sulphuric acid. The weight of the precipitate multi- 
plied by the factor 5.408, will give the weight of benzaldehyde in 100 cc. 
of the sample. If duplicate determinations do not agree, repeat the 
operations, using a larger quantity of the reagent. 

Hortvet and West Method.-^ — Measure 10 cc. of the extract into a 
loo-cc. flask, add 10 cc. of a 10% sodium hydroxide solution, and 20 cc. 
of a 3% hydrogen peroxide solution, cover with a watch-glass and place 
on a water-oven. Oxidation of the aldehyde to benzoic acid begins 
almost immediately and should be continued from five to ten minutes 
after all odor of benzaldehyde has disappeared, which usually requires 
from twenty to thirty minutes. If nitrobenzol be present, it will be 
indicated at this point by its odor. When the oxidation of the aldehyde 
is complete, remove the flask from the water-oven, transfer the contents 



* Jour. Ind. Eng. Chem., i, 1909, p. 256. 
t Ibid., p. 86. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 945 

to a separatory funnel, rinsing off the watch-glass, add lo cc. of a 20% 
sulphuric acid solution, and cool the contents of the funnel to room 
temperature under the water tap. Extract the benzoic acid with three 
portions of 50, 30, and 20 cc. of ether, respectively, wash the combined 
extracts in another separatory funnel with two portions of from 25 to 
30 cc. of distilled water, or until all the sulphuric acid is removed. Filter 
into a tared dish, wash with ether, allow to evaporate at room tempera- 
ture, and finally dry over night in a desiccator, and weigh. The per 
cent of benzaldehyde (B) is obtained from the weight of the acid {W) 
by the following forniula: 

_ 0.869X10XTF 

£> = . 

1.045 

If desired the benzoic acid may be titrated, and the benzaldehyde 
calculated from the amount of standard alkali required for neutraliza- 
tion. The process is as follows: Dissolve the benzoic acid obtained as 
above described, except that it need not be dried in a desiccator, in 95% 
alcohol made neutral to phenolphthalein with tenth-normal sodium 
hydroxide, dilute with an equal volume of water, and titrate with tenth- 
normal sodium hydroxide, using phenolphthalein as indicator. The 
per cent of benzaldehyde (B) is calculated from the cc. of tenth-normal 
alkali (F) by the following formula: 

FX0.01061XT0 

B — . 

1.045 

Detection of Nitrobenzol.* — Boil 15 cc. of the extract in a test-tube 
with a few drops of a strong solution of potassium hydroxide. Nitro- 
benzol produces a blood-red coloration. 

Distinction between Benzaldehyde and Nitrobenzol. — Treat 20 cc. 
of the extract with 5 to 10 cc. of a cold, saturated aqueous solution of 
sodium bisulphite in a test-tube, and shake vigorously. Transfer to 
an evaporating-dish, and heat on the water-bath till the alcohol is driven 
off. At this stage benzaldehyde remains in the hot solution as a crystal- 
line salt, and the solution gives off no almond odor. 

Nitrobenzol, on the contrary, does not combine with the bisulphite 
and is insoluble, forming globules of oil on the surface of the hot liquid, 
and in addition giving off the pungent odor so characteristic of the sub- 
stance. 

* Holde, Jour. Soc. Chem. Ind., 13, 1893, p. 906. 



946 FOOD INSPECTION AND ANALYSIS. 

Separation of Nitrobenzol and Benzaldehyde. — If by the qualitative 
test nitrobenzol is found, shake vigorously as before 50 cc. of the extract 
with ID cc. of the saturated sodium bisulphite solution in a corked flask, 
and transfer with 100 cc. of vi^ater to a large separatory funnel. Shake 
out the nitrobenzol from the solution with four successive portions of 
petroleum ether of 15 to 20 cc. each, and after washing with water the 
combined petroleum ether, transfer it to a tared dish, in which it is allowed 
to evaporate spontaneously. 

It is extremely difficult to avoid loss- of some of the nitrobenzol by 
this process, but even if the weighed residue fails to show the full amount 
originally used, enough will usually be extracted to admit of testing on 
the refractometer, and of otherwise verifying its character. 

After removal of the nitrobenzol, make the residual solution in the 
separatory funnel strongly alkaline with sodium hydroxide, and shake 
out the benzaldehyde, if present, with petroleum ether as previously 
described. If after making the solution alkaline no odor of benzalde- 
hyde is apparent, the absence of benzaldehyde may be inferred. 

Distinction between Artificial Benzaldehyde and Pure Almond Oil. — 
Test the final residue from the ether extract by shaking with an equal 
volume of concentrated sulphuric acid in a test-tube. With natural 
oil of almonds a clear, brilliant, but dark currant-red color is produced, 
while with artificial benzaldehyde^ the acid produces a dirty brown color 
with the formation of a precipitate. 

Determination of Alcohol. — In the absence of other flavoring sub- 
stances than nitrobenzol and benzaldehyde, which are rarely present 
to an extent exceeding 1%, a sufficiently close approximation for most 
purposes can be gained by estimating the alcohol from the direct specific 
gravity of the extract. 

Detection of Hydrocyanic Acid, — To a few cubic centimeters of 
extract in a test-tube add a few drops of a mixture of solutions of ferrous 
sulphate and ferric chloride, the ferrous salt being in excess. Make 
alkaline with sodium hydroxide, and add enough dilute hydrochloric 
acid to dissolve the precipitate formed by the alkali. Presence of a blue 
coloration or precipitate, due to the formation of Prussian blue, indicates 
hydrocyanic acid. The reaction is very delicate. 

Determination of Hydrocyanic Acid.*^ — Hydrocyanic acid may be 
determined by titration with tenth-normal silver nitrate solution. 25 cc. 

* Vielhaber, Arch. Pharm. (3), 13, p. 408. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 947 

of the extract are measured into a flask, and 5 cc. of freshly prepared 
magnesium hydroxide suspended in water are added, or enough to 
make the reaction alkaline. 

A few drops of a solution of potassium chromate are then introduced, 
and the tenth-normal silver nitrate solution added till, with shaking, the 
formation of the red silver chromate indicates the end-point, i cc. of 
silver solution equals 0.0027 gram of hydrocyanic acid. 

WINTERGREEN EXTRACT. 

Wintergreen Oil. — True oil of wintergreen is obtained by distillation 
from the leaves of the wintergreen plant {GauUheria procumbens L.). 
Gildermeister and Hoffmann* state that the specific gravity at 15° is 
1. 180 to 1.187, the boiling-point 218 to 221° C. It is slightly lasvo- 
rotatory (a^=— o.o°25' to —1°). 

Oil of betula or sweet birch is distilled from the bark of the black 
birch (Betula lenta L.). It has the same specific gravity and boiling- 
point as oil of wintergreen, but unhke the latter is optically inactive. 
It differs somewhat from oil of wintergreen in taste and odor, but is 
hardly distinguishable in these respects from synthetic methyl salicylate. 

Both oil of wintergreen and oil of sweet birch consist almost entirely 
of methyl salicylate, the former containing, according to Power and 
Kleber,t as much as 99.8% of this substance, 

U. S. Standards. — Oil of Wintergreen is the volatile oil distilled from 
the leaves of the GauUheria procumbens L. 

Wintergreen Extract is the flavoring extract prepared from oil of 
wintergreen, and contains not less than 3% by volume of oil of winter- 
green. 

Spirit of Gautheria of the U. S. P. is a mixture of 50 cc. of oil of 
wintergreen and 950 cc. of alcohol. It accordingly contains 5% by volume 
of the essential oil. 

Adulteration of Wintergreen Extract. — Synthetic methyl salicylate 
is very commonly substituted for both wintergreen and sweet birch oil, 
and sweet birch oil in turn for wintergreen oil. The production of true 
wintergreen oil is smafl, the so-called natural wintergreen oil of com- 
merce being usuaUy sweet birch oil. The sense of smell is the best 

*The Volatile Oils. Translated by Kremers, Milwaukee, 1900, p. 588. 
t Pharm. Rund., 13, p. 228. 



948 



FOOD INSPECTION AND ANALYSIS. 



means of distinguishing the two oils ; polarization is of rather uncertain 
value, owing to low rotatory power of the wintergreen oil. 

Determination of Wintergreen Oil. — Hortvet and Wesfs Method.^ 
— Measure lo cc. of the extract into a loo-cc. beaker, add lo cc. of io% 
potassium hydroxide solution, and heat the mixture over a boiling water- 
bath until the odor of oil of wintergreen has disappeared and the hquid 
is reduced to about one-half its original volume. By this treatment 
the methyl salicylate is converted into the potassium salt. Liberate the 
salicylic acid by the addition of an exciess of io% hydrochloric acid, 
cool, and extract in a separatory funnel with three portions of 40, 30, 
and 20 cc. of ether respectively. Pour the combined ether extracts 
through a dry filter into a weighed dish, wash the filter with 10 cc. of 
ether, evaporate filtrate and washings slowly at 50° C, dry one hour 
in a desiccator, and weigh. The per cent of wintergreen oil by volume 
(M) is obtained from the weight of salicylic acid (6) by the following 
formula: 

i.ioiXioX5 



M= 



i.i{ 



Howard^ s Method. — Proceed as described on page 931, except that 
the heavy oil is brought into the graduated portion of the Babcock bottle 
by addition of dilute sulphuric acid (1:2), taking care that the acid is 
not over 25° C. and avoiding agitation. 



PEPPERMINT EXTRACT 



Peppermint Oil is obtained from various plants of the genus Mentha, 
which are commonly classed as sub-species or varieties of M. piperita. 
Owing in large part to the botanical differences in the plants from which 



American 0.905(00.920 

English 0.900 to 0.910 

Japanese 0.895 to 0.900 

Saxon 0.900 to 0.915 

German 0.899 to 0.930 

French I 0.918 to 0.920 

Russian | 0.905 to 0.910 



specific Gravity. 



Rotation, arj. 



-18° to -T,T,° 
• 22° to — ^^1° 
-30° to -42° 
-25° to -33° 
-27° to -33° 
- 5° to - 9° 
-17° to -22° 



Total Menthol, 
Per Cent. 



48 to 60 
56 to 66 
70 to 91 
54 to 68 

43 to 46 
50.2 



* Jour. Ind. Eng. Chem., i, 1909, p. 90. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 949 

it is made, peppermint oil from different regions differs greatly in its 
chemical and physical constants as shown by the table on bottom of page 
948, compiled from figures given by Gildermeister and Hoffmann.* 

U. S. Standards. — Peppermint is the leaves and flowering tops of 
Mentha piperita L. 

Oil of Peppermint is the volatile oil obtained from peppermint, and 
contains not less than 50% by weight of menthol. 

Peppermint Extract is the flavoring extract prepared from oil of pepper- 
mint, or from peppermint, or both, and contains not less than 3% by 
volume of oil of peppermint. 

Analysis of Peppermint Extract. — Owing to the wide variation in the 
rotatory power of peppermint oil, only a roughly approximate idea of 
the oil content of peppermint extract can be gained by polarization. 
The variation in the percentage of menthol in the oil is also too great 
to perm.it of a method based on the amount of this constituent. Mitchell's 
precipitation method, as originally described (page 931), does not effect 
a complete separation of the oil, but Howard's modification (page 931) 
gives satisfactory results, and is well adapted for purposes of inspection. 

Boyles' distillation method (page 932) may also be used. 

SPEARMINT EXTRACT. 

U. S. Standards. — Spearmint is the leaves and flowering tops of 
Mentha spicala L. 

Oil of Spearmint is the volatile oil obtained from spearmint. 

Spearmint Extract is the flavoring extract prepared from oil of spear- 
mint, or from spearmint, or both, and contains not less than 3% by volume 
of oil of spearmint. 

SPICE EXTRACTS. 

Alcoholic solutions of the essential oils of spices are used to some 
extent instead of the spices themselves. The following are the definitions 
of these extracts and the oils from which they are prepared, as adopted 
by the joint committee on standards and the U. S. Secretary of Agri- 
culture : 

U. S. Standards. — Anise Extract is the flavoring extract prepared 
from oil of anise, and contains not less than 3% by volume of oil of 
anise. 



* The Volatile Oils. Translated by Edward Kremers, Milwaukee, 1900. 



950 FOOD INSPECTION AND ANALYSIS. 

Oil of Anise is the volatile oil obtained from the anise seed. 

Celery Seed Extract is the flavoring extract prepared from celery seed 
or the oil of celery seed, or both, and contains not less than 0.3% by 
volume of oil of celery seed. 

Oil of Celery Seed is the volatile oil obtained from celery seed. 

Cassia Extract is the flavoring extract prepared from oil of cassia, 
and contains not less than 2% by volume of oil of cassia. 

Oil of Cassia is the lead-free volatile oil obtained from the leaves 
or bark of Cinnamomum cassia BL, and contains not less than 75% by 
weight of cinnamic aldehyde. 

Cinnamon Extract is the flavoring extract prepared from oil of cinna- 
mon, and contains not less than 2% by volume of oil of cinnamon. 

Oil of Cinnamon is the lead-free volatile oil obtained from the bark 
of the Ceylon cinnamon {Cinnamomum zeylanicum Breyne), and contains 
not less than 65% by weight of cinnamic aldehyde and not more than 
10% by weight of eugenol. 

Clove Extract is the flavoring extract prepared from oil of cloves, and 
contains not less than 2% by volume of oil of cloves. 

Oil of Cloves is the lead-free, volatile oil obtained from cloves. 

Ginger Extract is the flavoring extract prepared from ginger, and 
contains in each 100 cc. the alcohol-soluble matters from not less than 
20 grams of ginger. 

Nutmeg Extract is the flavoring extract prepared from oil of nutmeg, 
and contains not less than 2% by volume of oil of nutmeg. 

Oil of Nutmeg is the volatile oil obtained from nutmegs. 

Savory Extract is the flavoring extract prepared from oil of savory, 
or from savory, or both, and contains not less than 0.35% by volume of 
oil of savory. 

Oil of Savory is the volatile oil obtained from savory. 

Star Anise Extract is the flavoring extract prepared from oil of star 
anise, and contains not less than 3% by volume of oil of star anise. 

Oil of Star Anise is the volatile oil distilled from the fruit of the star 
anise (Jllicium verum Hook). 

Sweet Basil Extract is the flavoring extract prepared from oil of 
sweet basil; or from sweet basil, or both, and contains not less than 0.1% 
by volume of oil of sweet basil. 

Sweet Basil, Basil, is the leaves and tops of Ocymum hasilicum L. 

Oil of Sweet Basil is the volatile oil obtained from basil. 

Sweet Marjoram Extract, Marjoram Extract, is the flavoring extract 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 951 

prepared from the oil of marjoram, or from marjoram, or both, and con- 
tains not less than i% by volume of oil of marjoram. 

Oil of Marjoram is the volatile oil obtained from marjoram. 

Thyme Extract is the flavoring extract prepared from oil of thyme, or from 
thyme, or both, and contains not less than 0.2% by volume of oil of thyme. 

Oil of Thyme is the volatile oil obtained from thyme. 

Determination of Essential Oil in Alcoholic Cinnamon, Cassia, and 
Clove Extracts. — Howard's Method. — Proceed as with wintergreen extract, 
page 948. 

Hortvet and Wesfs Method.'^ — Place 10 cc. of the extract and 50 cc. 
of water in a separatory funnel, and extract with three portions of ether 
measuring respectively 50, 30, and 20 cc. Wash the combined extracts 
successively with 25 and 30 cc. of distilled water, and filter through a 
dry funnel into a wide-mouth flask, washing out the funnel and filter 
with a little ether. In the case of cinnamon extract, transfer the ether 
extract before filtering to a 150-cc. flask, shake for a few minutes with 
some granulated calcium chloride, then filter in the manner described. 
Evaporate off the ether as rapidly as possible on a boiling water-bath 
until only a few drops remain. At this point remove the flask from the 
bath, and rotate rapidly for a- few minutes, spreading the residue over 
the sides of the flask. The rapid evaporation of the remaining ether cools 
the flask to near room temperature. When the odor of ether has dis- 
appeared, stopper the flask and weigh. 

In the case of cassia and clove oils, where the ether extract is not 
first dried with calcium chloride, a slight cloudiness gathers on the flask 
as the last traces of ether disappear, due to the presence of a little moisture. 
In such case allow the flask to stand on the balance-pan until the film dis- 
appears, requiring not longer than two or three minutes, then stopper, 
and weigh. 

The per cent of oil by volume (F) is calculated from the weight of 
oil (W) by the following formula: 

looXW 



V- 



10 X 1.050 



The oil thus extracted may be used for determination of the refractive 
index. After dissolving in a little alcohol it may be tested with ferric 
chloride solution. By this test cinnamon oil gives a green, cassia oil a 
brown, and clove oil a deep blue, coloration. 

* Jour. Ind. Eng Chem., i, 1909, p. 88. 



952 FOOD INSPECTION AND ANALYSIS. 

Determination of Essential Oil in Non-alcoholic Cinnamon, Cassia, 
and Clove Extracts.— ^o^'/e^ Modification of the Howard Method.'^— 
Dilute lo cc. of the sample with 95% alcohol to 50 cc, as in the case of 
lemon, and filter. Place 10 cc. of the filtrate in a separatory funnel con- 
taining 50 cc. of water, add i cc. of hydrochloric acid (i : i), and shake 
out four times with 25-cc. portions of ether. Wash the combined ether 
extracts twice with water and then shake for a few minutes with about 
5 grams of granular calcium chloride. Place a small piece of cotton 
in the outlet of the separatory funnel and draw the ether into a tared 
beaker. Evaporate the ether on a boiling water-bath, place in a desiccator 
for three minutes, and weigh. Divide the weight found by the specific 
gravity of the oil to obtain the per cent of oil by volume. 

Determination of Essential Oil in Nutmeg Extract.— Follow Mitchell's 
precipitation method (page 931). In the case of non-alcoholic nutmeg 
extracts convert first into an alcoholic extract as described for non-alcoholic 
lemon extract (page 931). 

Determination of Solids in Ginger ^Extract. f— Evaporate 10 cc. on 
a boiling water-bath to dryness, dry for two hours in a boiling water oven 
and weigh. 

Determination of Alcohol in Ginger Extract. f— Proceed as with vanilla 
extract (page 926). 

Detection of Ginger in Ginger ExtTact.-\— Seeker Method.— Dilute 
10 cc. of the extract to 30 cc, evaporate off 20 cc, decant into a separatory 
funnel and extract with an equal volume of ether. Evaporate the ether 
spontaneously in a porcelain dish and to the residue add 5 cc. of 75% 
sulphuric acid and 5 mg. of vanillin. Allow to stand for fifteen minutes 
and add an equal volume of water. In the presence of ginger extract an 
azure blue color develops. 

Detection of Capsicum in Ginger ExtrsiCt—Nelso7i-La Wall-Doyle 
Method.^ — To 10 cc of the extract cautiously add dilute sodium hydroxide 
until the solution reacts very slightly alkaline with litmus paper. Evapo- 
rate at about 70° C. to about one-quarter of the original volume, render 
slightly acid with dilute sulphuric acid, testing with litmus paper. Trans- 
fer to a separatory funnel, rinsing the evaporating dish with water, and 
extract with an equal volume of ether, avoiding emulsilication by shak- 

* Jour. Ind. Eng. Chem., 10, 1918, p. 537. 
t U. S. Dept. of Agric, Bur. of Chem., Bui. 137, 1911, p. 75. 

t Jour. Ind. Eng. Chem., 2, 1910, p. 419; U. S. Dept. of Agric, Bur. of Chem., Bui. 137, 
1911, p. 75; Bui. 152, 1912, p. 137. 



1 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 953 

ing the funnel gently for a minute or two. Draw off the lower layer and 
wash the ether extract once with about lo cc. of water. Transfer the 
washed ether extract to a small evaporating dish, render decidedly alkaline 
with alcoholic potassium hydroxide, and evaporate at about 70° until 
the residue is pasty; then add about 20 cc. more of half-normal alcoholic 
potash and allow to stand on a steam bath until the gingerol is com- 
pletely saponified, which usually requires about one-half hour. Dis- 
solve the residue in a little water and transfer with water to a small sepa- 
ratory funnel.- The volume should not exceed 50 cc. Extract the alkaline 
solution with an equal volume of ether. Wash the ether extract repeatedly 
with small amounts of water until no longer alkaline to litmus. Transfer 
the washed extract to a small evaporating dish, allow the ether to evaporate 
spontaneously, and finally, ^ast the residue for capsicum by moistening 
the tip of the finger, rubbing it around on the bottom and sides of the 
dish, and then applying the finger to the end of the tongue. A hot, stinging, 
or prickly sensation, which persists for several minutes, indicates capsicum 
or other foreign pungent substances. 

ROSE EXTRACT. 

U. S. Standards. — Rose Extract is the flavoring extract prepared from 
otto of roses, with or without red rose petals, and contains not less than 
0.4% by volume of otto of roses. 

Otto of Roses is the volatile oil obtained from the petals of Rosa 
damascena Mill., R. centifolia L., or R. moschata L. 

Determination of Rose Oil.— Hortvet and West's Method."^ — Measure 
25 cc. of the extract into a separatory funnel, add 50 cc. of water, mix 
thoroughly, acidify with i cc. of hydrochloric acid (1:1), and extract 
with three portions of 20 cc. each of ether. Transfer the combined 
ether extracts to a 150-cc. flask, shake for a few minutes with some 
granulated calcium chloride, allow to settle until clear, then decant 
through a dry filter into a flat bottom glass dish previously weighed 
together with a cover-glass. Wash the calcium chloride and filter twice 
with 10 cc. of ether, and add the washings to the glass dish. Cover 
the dish, place in a vacuum desiccator over sulphuric acid, allow to 
remain until all traces of ether and alcohol are removed, and weigh. 
Repeat the drying in the desiccator, for one hour periods, until the weight 
is practically constant. The final weight, divided by 0.86 and multiplied 
by 5, gives the per cent of oil of rose by volume. 

* Jour. Ind. Eng. Chem., r, 1909, p. 89. 



^ 



954 FOOD INSPECTION AND ANALYSIS. 

IMITATION FRUIT FLAVORS. 

Nearly all the fruits possess distinctive flavors, which are desirable 
in food preparations, and which may be made to impart their ilavor to 
such substances as confections, ice cream, dessert mixtures, jellies, etc., 
by simply mixing with these foods the fresh or preserved fruit or fruit 
juice in sufficient quantity. In many cases, however, it is not found 
possible or practicable to prepare from the frui.s themselves an extract 
sufficiency concentrated to give the distinctive fruit flavor, when used 
in moderate quantity, and hence the use of artificial fruit essences made 
up of compound ethers, mixed in varying combinations and proportions 
to imitate more or less closely various fruit flavors. 

These ethers are usually much more pungent and penetrating than 
the fruits which they imitate, and, while lacking the delicacy and refine- 
ment of the original frui.s, serve to impart a certain semblance of the 
genuine flavor in a convenient and highly concentrated form. 

Some of the single compound ethers possess a remarkable resemblance 
to particular fruits, while to imitate other fruits a mixture of various 
ethers and flavoring materials, such as lemon and other volatile oils, 
vanilla, organic acids, chloroform, etc., is necessary. These artificial 
essences should in all cases be sold as such, and not as "pure fruit 
flavors." 

Imitation Pineapple Essence is made up by dissolving in alcohol butyric 
ether, C4H7(C2H5)02, which possesses a distinct pineapple flavor, and 
is prepared by mixing loo par^s of buyric acid (C^HgOj), loo parts of 
alcohol, and 50 parts of sulphuric acid, and shaking. Butyric ether is 
sparingly soluble in water, and boils at 121° C. 

Imitation Quince Essence depends as a basis on ethyl pelargonate, 
sometimes called pelargonic or oenanthic ether, CjHsjCgHiyOj, dissolved 
in alcohol. Pelargonic ether is formed by digestion with the aid of heat 
of pelargonic acid and alcohol. Pelargonic acid, C<jHjg02, is first obtained 
by the action of nitric acid on oil of rue. Pelargonic ether is a colorless 
liquid, having a specific gravi y of 0.8635 ^-t 17.5° C. Its boiling-point 
is 227° to 228° C. It is insoluble in water. 

Imitation Jargonelle Pear Essence consists of an alcoholic solution 
of amyl or pentyl acetate, CsHnjCzHgOj. This is prepared by distilling 
a mixture of one part of amyl alcohol, two parts of potassium acetate, 
and one part of concentrated sulphuric acid. It is a colorless liquid, 
insoluble in water, and having a boiling-point of 137° C. 



FLAVORING EXTRACTS AND THEIR SUBSTITUTES. 



955 



Imitation Banana Essence is made up of a mixture of amyl acetate 
and butyric ether. 

Imitation Apple Essence is composed of an alcoholic solution of amyl 
valerianate, sometimes called apple oil, C5Hii,C5H902, prepared by mix- 
ing four parts of amyl alcohol with four of sulphuric acid, and adding 

COMPOSITION OF IMITATION ESSENCES. 



- 


j 

o 
2 
u 


3s 


■a 

aj 
< 




oW 




o 

S . 


D 


C « 


Oil of Persi- | 
cot. 




o 


Pineapple 

Melon 


I 




I 
2 

I 

I 
2 
2 
2 






5 
4 

5 

I 


5 








lO 




5 
5 
5 

I 
5 
5 

lO 
ID 

5 
5 


I 

I 
I 




Strawberry 




I 
I 


1 






Raspberry 






I 

I 


I 
I 

lO 




I 




Gooseberry 






Grape 


2 

I 
2 


I 


2 










I 




I 

5 

5 








Orange 


I 


Pear 


I 


2 

4 

5 


I 




I^emon 

Black cherry. . . . 


I 


I 


2 




Cherry 
















Plum 






5 


I 


2 
lO 

5 






Apricot 


I 




5 
5 




I 




Peach 




2 

I 


5 
5 


5 




Currant 






I 


I 





















o 
.c 
o 
o 

< 
< 




o 
>. 

J. <u 

Em 
< 


o 

'c 
.2 

_aj 


d 

o 

i 
►J 



O 


IP 

M 

o 

"o 
O 


Saturated Alcholic 
Solutions of 






rt-d 




o 

So 


o 
■g-d 

pa 


d 

3 








ID 
















3 
3 


Melon .............. 




















Strawberry. 




3 
I 


2 

I 
















Raspberry. .......... 










5 
5 
5 


I 


I 
I 

3 


I 


4 


Gooseberry. 










Grape 
















Apple 








lO 






4 


Orange 




I 

2 






lO 


I 






Pear 


















Lemon 








lO 




lO 


I 


I 


2 

I 


5 


Black cherry 










Cherry 
















3 
8 


Plum 




















Apricot 






I 








I 








4 
5 


Peach 














Currant 












5 




I 


I 



















956 FOOD INSPECTION AND ANALYSIS. 

the mixture when cold to five parts of valerianic acid. The specific 
gravity of amyl valerianate is 0.879 ^^ 0° C. and its boiling-point is 
188° C. 

The table on p. 955, prepared by Kletzinsky, show^s the composition 
of a large variety of these artificial essences. The numerals in the various 
columns indicate the parts by volume to be added to 100 parts of deodor- 
ized alcohol. 

Determination of Esters. — Add to 25 grams of the extract 2 cc. of 
sodium hydroxide solution (100 grams in 100 cc. of water), 100 cc. of 
water and heat under a reflux condenser one half-hour. Acidify with 
5 cc. of dilute sulphuric acid (1:4), add a few pieces of pumice stone, 
distil in a current of steam and titrate the distillate with tenth-normal 
alkali, using phenophthalein as indicator. The number of cc. required 
represents the total volatile acids free and combined. Determine 
free volatile acids, if present by direct distillation and titration of the 
distillate. The difference between the two titrations is calculated as 
ethyl acetate. 



CHAPTER XXI. 
VEGETABLE AND FRUIT PRODUCTS. 

CANNED VEGETABLES AND FRUITS. 

Strictly speaking all varieties of canned foods found in the market, 
whether meats, fruits, or vegetables, in order to be entirely beyond criti- 
cism, should not differ from the corresponding freshly cooked varieties 
which they are intended to replace, excepting that they are free from 
bacteria. Such a degree of perfection is, however, difficult, even if pos- 
sible, to attain, and nearly all commercial canned products, even if made 
from the best materials, are liable to contain either antiseptic substances 
or coloring-matter intentionally added by the manufacturer, or metallic 
impurities accidentally derived from the vessels in which they are pre- 
pared, or from the containers in which they are sealed. In spite of these 
objections, canned foods form a convenient, and in some cases indispensa- 
ble means of furnishing both necessities and luxuries for the table. The 
canning of foods is especially useful for preserving them during long 
periods of time, for enabling certain fruits and vegetables to be enjoyed 
out of season, and for furnishing supplies in a convenient manner to inac- 
cessible places where fresh foods are not readily obtainable, as in the 
case of armies in the field, of vessels at sea, of campers in the woods, etc* 
Canned goods in great variety are used in nearly every household. 

When it is considered that in the United States alone several hundred 
million cans of tomatoes, corn, and peas are packed in a single year, to 
say nothing of an ever-increasing variety of other foods, some idea may 
be gained of the enormous proportions to which the canning industry 
has grown. It is comforting to know that, in view of their wide-spread 
consumption, the greater portion of such foods found on the market are 
comparatively harmless, as is evidenced by the fact that few cases of injury 
to health have been directly traceable to their use. 

Method of Canning Food. — Various modifications as to details exist 
with different products and in different localities, but in general the prin- 
ciple of canning in tin is the same in all cases. The fresh product is 

957 



958 FOOD INSPECTION AND ANALYSIS. 

cleaned carefully, the refuse removed by shelling, paring, or other treat- 
ment, in most cases " blanched " (immersed in hot water for a period of 
time), and packed into cans. A weak brine to which has been added a 
little sugar in the case of corn, peas, etc., is added to vegetables and a 
syrup of various strengths to fruits. If the soldered can is used the cap is 
attached at this stage of the process, if the sanitary can, it is left open and 
" exhausted " at a temperature slightly below the boiling-point of water. 
In either case the process of sterilization is then carried out by heating in a 
saline solution or a dry retort at a suitable temperature above ioo° C. 
The soldered can at this point is punctured to allow the escape of the com- 
pressed air, then closed with a drop of solder, while the sanitary can is 
sealed by double seaming on the cover using a special cement to insure 
tightness. 

The canning of peas is fully described by Bitting * and of other vege- 
tables and fruits by Za valla. t 

Cooked vegetables and fruit products put up in glass jars or bottles 
are tightly sealed when hot, either with screw-caps or with some form of 
cover held by a clamp, or with metal or hard-rubber caps fitting over a 
flanged mouth. Commonly a soft-rubber ring is inserted between the 
cover and the mouth of the jar or bottle. The material of the cover is 
generally either glass, porcelain, or metal. Cork stoppers are, however, 
sometimes pressed into the mouths of the bottles, and made extra tight 
therein with sealing-wax. These stoppers are occasionally soaked in 
paraffin. Thus the contents of the jar may be exposed to porcelain, 
glass, metal, rubber, or cork, according to the material of the cover and 
the method of sealing. 

The preservation of food by canning was long thought to be due to 
the perfect exclusion of air, but is now known to depend on the perfect 
sterilization, or destruction of bacteria, and it has been proved that as 
far as keeping qualities are concerned, it makes no difference whether 
or not air is present in the can, if the contents are sterile, though for pur- 
poses of inspection the vacuum, in the case of tin cans, is of great use, 
in that as a natural consequence of the vacuum, when the goods are sound, 
the ends of the cans are usually concave. The highest aim of the canner 
should be to retain in his product as far as possible the appearance, palata- 
bility, and nutritive value of the freshly cooked food. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 125, 1909. 
t Canning of Fruits and Vegetables, New York, 1916. 



VEGETABLE AND FRUIT PRODUCTS. 



959 



Proximate Analyses of canned vegetables and fruits, as found on the 
market, have been made by various authors, and are useful in showing the 
food value of the products. The results in the table as given below are 
from Atwater and Bryant's compilations. There is a lack of data on 
samples of known origin on which suitable standards may be based. 

PROXIMATE COMPOSITION OF CANNED VEGETABLES AND FRUITS.* 



CANNED VEGETABLES. 

Artichokes. 

Asparapug 

Beans, baked 

' ' string 

" Lima 

Brussels sprouts 

Corn, green 

Peas, green 

Pumpkin 

Squash 

Succotash 

Tomatoes 

CANNED FRUITS. 

Apples, crab 

Apple sauce 

Apricots 

Blackberries 

Blueberries 

Cherries 

Peaches 

Pears 

Pineapples 

Strawberries 



0) 








>> 






o'c3 


u 


.S 




m iH nj 


13^ 
















^< 


^ 


fx, 


U^ 


^0-0 


i^ 


< 


3 


92.5 


.8 




5-0 


.6 


1-7 


14 


94-4 


t-5 


.1 


2.8 


•5 


1.2 


21 


68.9 


6.9 


2-5 


19.6 


2-5 


2.1 


29 


93-7 


I.I 


.1 


3-8 


-5 


1-3 


16 


79-5 


4.0 


•3 


14.6 


1.2 


1.6 


I 


93-7 


1-5 


.1 


3-4 


-5 


1-3 


52 


76.1 


2.8 


1.2 


19.0 


.8 


•9 


88 


85-3 


3-^ 


.2 


9.8 


1.2 


I.I 


7 


91.6 


.8 


.2 


6-7 


I.I 


•7 


5 


87.6 


■9 


•5 


10.5 


•7 


.5 


12 


75-9 


3-^ 


I.O 


18.6 


.9 


.9 


19 


94.0 


1.2 


.2 


4.0 


•5 


.6 


I 


42.4 


•3 


2.4 


54-4 




• 5 


I 


61. 1 


.2 


.8 


37-2 




• 7 


I 


81.4 


.9 




17-3 




.4 


I 


40.0 


.8 


2.1 


56.4 




.7 


3 


85.6 


.6 


.6 


12.8 




.4 


I 


77.2 


I.I 


.1 


21. 1 




-5 


3 


88.1 


•7 


.1 


10.8 




•3 


4 


81. 1 


• 3 


•3 


18.0 




•3 


I 


61.8 


.4 


-7 


36-4 




•7 


I 


74-8 


•7 




24.0 




-5 



> c 
<u S o 



IIO 

85 

600 

95 
360 

95 
455 
255 
150 
235 
455 
105 



1,120 

730 
340 
1. 150 
275 
415 
220 

355 
715 
460 



•U. S. Dept. of Agric, Exp. Sta. Bui. 28, p. 70. 

The determination of the drained solids is often made with the view 
of detecting, especially in tomatoes, an excess of water added as such or 
as drainage from a better grade, but there are various unavoidable influ- 
ences which affect the results. In addition to natural variations of canned 
tomatoes Bigelow * has shown that freezing, agitation during shipment, and 
other factors exert no little influence, while McGill f found as great vari- 
ation in the different cans of the same brand as between the average of 
different brands. Obviously this determination is not applicable to canned 
vegetables such as pumpkin, which have little or no liquor. 

* Jour. Assn. Off. Agr. Chem., 3, 1917, p. i. 
fLab. Int. Rev. Dept. Canada, Bui. 357, 1916. 



960 FOOD INSPECTION AND ANALYSIS. 

Decomposition. — " Swells." — In the case of canned vegetables and 
fruit products, decomposition rarely results in the formation of ptomaines 
even after the can has long been open, though these toxins are sometimes 
formed in canned meat and fish. Spoilage is readily apparent after open- 
ing a can, from a cursory examination of its contents. The appearance, 
taste, and odor will not fail to indicate the unfitness of the contents for 
food, if decomposition is at all advanced. It is, however, often of great 
advantage to detect spoiled cans without opening. As a rule, when a can 
is spoiled, it is usually in the condition termed " blown," i.e., with its 
ends convex, instead of normal or concave. 

Doremus * has shown that when the cans have become putrid carbon 
dioxide and hydrogen are the chief gases to be found. 

According to Prescott and Underwood, f although nearly all forms of 
bacterial decomposition are accompanied by bulging of the ends of the cans, 
there are some exceptions. In the souring of canned sweet corn, which 
they trace to at least twelve varieties of bacteria, it is exceptional that 
swelling occurs. These "flat sours" are detected as follows: Boil 
the cans for an hour, causing the ends of all to swell, then cool, and set 
aside for eight hours, during which the sound cans will snap back, while 
the unsound will continue convex, by reason of the fact that the swell- 
ing in this case is due to the generation of gas by the bacteria present. 

Ordinarily, in the factory inspection of canned goods before shipping, 
not only are the bulged cans or " swells," as they are termed, sifted out, 
but the condition of the cans is tested by sounding or striking the cans. 
If the contents are sweet, a peculiar note is produced when the can is struck, 
readily distinguishable from the dull tone of the unsound can by anyone 
familiar with the work. 

** Springers" are cans which may appear normal in ordinary weather 
but have bulged ends on hot days. Baker, J who has made a special study 
of springers, has found that the gas present consists chiefly of carbon dioxide 
formed during processing, nitrogen from the air remaining after oxygen 
has combined with the tin or iron or else contents of the can, and usually 
hydrogen. He concludes that this abnormality may be largely obviated 
by avoiding over filling, closing the can while hot, thus producing a vacuum, 
avoiding delay in the process of canning, and using enameled cans for 
foods with high acidity. 

* Jour. Amer. Chem. Soc, 19, 1897, p. 733. 
fTech. Quart., 10, 1897, p. 183; 11, 1898, p. 6. 
X 8th Int. Cong. App. Chem., 18, 191 2, pp. 39, 45. 



VEGETABLE AND FRUIT PRODUCTS. 961 

Bigelow * believes the hydrogen is formed by organic acids acting on 
the iron of the can, hence non-acid foods rarely form springers due to 
hydrogen. He further states that the three staples, tomatoes, peas, and 
corn, neither attack the metal considerably nor form springers from this 
cause. When the bulging is pronounced he advocates condemning the 
product because of the iron taste and the difficulty of distinguishing such 
springers from swells due to biological decomposition. 

Metallic Impurities. — Salts of Lead and Tin are commonly met 
with in varying amounts in nearly all classes of products put up in tin. The 
quantity dissolved depends largely on the character of the tin plate used in 
the manufacture of the can, as well as on how the solder is applied. Much 
depends also on the nature of the food product and its acidity. Formerly 
much danger was apprehended from the use of the so-called terne plate 
as a material for cans. This consists of an alloy of lead and tin, coated 
on iron plate and intended for use as roofing. Sometimes two parts of 
lead to one part of tin are found in terne plate. Only the better grades 
of bright tin plate should be used in canning. There is reason to believe 
that no terne plate is at [^present used in cans. In 1892 the plating alloy 
of 47 samples of tin cans in which peas had been put up were examined 
in the Bureau of Chemistry of the U. S. Department of Agriculture,! and 
the amount of lead found varied from 0% to 13%. Only 4 samples were 
found to exceed 5%, and 24 contained less than 1%. 

The construction of the can should be such that practically no soldered 
surface is exposed to the contents, the joints being lapped and soldered 
on the outside. In spite of this, however, it is not unusual to find cans 
soldered on the inside, or lumps of solder in the can from the sealing of 
the tapped hole. From 51% to 65% of lead was found in the solder taken 
from the interior of twenty-four of the cans mentioned in the preceding 
paragraph. { 

Cans lacquered on the inside to prevent contact of the metal with the 
food are coming into use but as yet are not an unqualified success. Some 
of the lacquers which have proved most efficient are objectionable because 
of their lead content. 

Action of Fruits and Vegetables on Tin Plate. — A large variety of 
canned products have been examined in the laboratory of the Massachu- 



* Nat. Can. Assn. Res. Lab., Bui. 2, 1914. 
t Bui. 13, p. 1036. 
J Ibid., p. 1038. 



962 



FOOD INSPECTION AND ANALYSIS. 



setts State Board of Health, with a view to determining the quantity of 
tin contained in solution. The results have shown that though notable 
traces of tin were found in acid fruits and rhubarb, and large traces in 
some green vegetables, canned blueberries were found to contain, as a 
rule, much more tin in solution than any other canned goods examined. It 
is assumed that the tin was, at least in considerable part, still held in 
solution by the fruit acids, inasmuch as the metal was found in the filtered 
juice. In every instance the inner tin lining was found to be exten- 
sively corroded, and in some cases it had been almost entirely dissolved 




H 



Fig. 119. — Interior of Blueberry Cans, Cut Open to Show the Corrosion by Acid of the 

Fruit Juice. 

o£f, leaving the underlying iron bare. Fig. 119 shows the appearance 
of two of these cans, split open to show the inner surfaces. The corro- 
sion is apparent. Eleven samples of canned blueberries, representing 
seven brands, were examined in 1894 by Worcester, showing an amount 
of tin solution (calculated as Sn02) varying from 0.066 to 0.27 gram per 
can of 615-CC. capacity. 

In 1899 samples of various canned products were examined for lead 
and tin in the author's laboratory, the results of which are thus sum- 
marized :* 



An. Rep. Mass. State Board of Health, 1890, p. 623. 



VEGETABLE AND FRUIT PRODUCTS. 



963 



Strawberries. 

Highest. . . 

Lowest. . . . 
Raspberries. . 

Highest. . . 

Lowest. . . . 
Blueberries. . 

Highest. . . 

Lowest. 

Tomatoes . . . . 

Highest. . . 

Lowest. . . . , 
String beans. . 

Highest. . . , 

Lowest. . . . , 
Peas 

Highest. . . , 

Lowest. 

Corn 

' Highest. . . . 

Lowest. . . . , 
Lima beans. .. 
Succotash. . . . 
Squash 

Highest. . . . 

Lowest 

Pumpkin 

Rhubarb 

Asparagus . . . . 
Mutton broth. 
Tomato soup . 

Sahnon 

Lobster 



Tin, Grams. 



-0393 
.0124 

.0848 
.0725 

.2226 

.0056 

■0515 
.0146 

-0499 
.0065 

.0046 

.0024 

.0101 
.0045 
.0064 
.0039 

■1793 
■1577 
.1844 

•3506 
.1249 
.0114 
.0023 
.0319 
.0411 



Lead, Grams. 



.0004 
.0000 



.0002 
.0001 



.0021 
.0004 



.0004 
.0001 



. 0003 
.0008 



.0000 
.0001 

.0011 
.0001 
.0004 
.0001 

.0087 
. 0003 
.0019 
.0002 
.COO I 

.0001 
.0002 
.0001 

.0001 



Capacity of 
Can, cc. 



615 

615 
615 
950 
650 

615 
615 



650 
650 
950 



950 
615 
930 
950 

37«^ 
470 

430 



A wide range of variation exists in the amount of tin dissolved. 
Pumpkin and squash, for example, dissolve surprisingly large quantities, 
considering the supposed inert nature of these vegetables. 

In samples of canned sardines put up in mustard, vinegar, and oil, 
the Massachusetts Board has found as high as 0.376 gram of tin in a 
half-pound can. In these cases the corrosion of the interior of the cans 
was very marked.* 

Effect of Time on Amount of Tin Dissolved. — A series of experi- 
ments was conducted by the author in 1899 f on the action of various 
fruit acids on tin, with a view to ascertaining, among other facts, whether 
or not the element of time exerts an appreciable difference in the results. 

Samples of various canned fruits and vegetables were titrated for 

* The U. S. Government, pending further investigation, permits 300 mg. of tin per kilo 
in canned goods. F. L D. No. 126. 

t An. Rep. Mass. State Board of Health, 1899, p. 624. 



964 



FOOD INSPECTION AND ANALYSIS. 



I 



their acidity. It was found that certain samples of canned blueberries, 
for instance, had an -^cidity of about one-twentieth normal. In the case 
of strawberries, the acidity was about one-sixth normal. Canned rasp- 
berries were found to be about one-tenth normal in acidity, while the 
acidity of canned tomatoes varied from one-tenth to one-fourteenth normal. 
Solutions of one-fifth, one-tenth, and one-fifteenth-normal malx acid, 
one-tenth and one-fifteenth-normal tartaric acid, one-tenth and one- 
fifteenth-normal citric acid, and one-tenth-normal acetic acid were 
prepared and sealed in pint glass jars, having about the same capacity 
as the ordinary-sized tin fruit cans, each jar containing an amount of 
tin plate equivalent to the interior exposed surface of a can. Solutions 
thus sealed were kept for three months, six months, and a year, and 
examined at the end of these respective periods for tin. The results 
showing the amount of tin found at the end of three months in each 
case are given in the following list: 



ACTION OF FRUIT ACIDS ON TIN IN THREE MONTHS. 



Acid. 


Grams of Tin 

in One Pint of 

Solution. 


Acid. 


Grams of Tin 
in One Pint of 

Solution. 


N/5 malic... 

N/io " 


0.0578 
0.0201 
0.0197 
0.0382 


N/15 tartaric 


0.0246 
0.0374 
O.C236 
0.0019 


N/io citric 


N/i!; " 


N/i? " 


N/ib tartaric ■. 


N/io acetic 







It was found that, as a rule, the amount dissolved in three months was 
the same as in six months or even a year. 

Tenth-normal acetic acid sealed in jars with tin plate, as in the case 
of the fruit acids, dissolved in three months 0.0019 gram, and in six months 
0.0083 gram of tin, which is much less than was obtained with fruit acids 
of the same strength, and with the samples of sardines referred to on 
page 263. 

Bigelow and Bacon find that shrimps contain monomethylamin, which 
corrodes the cans in which they are packed. Their experiments with 
volatile alkalis and amino acids present in vegetables of low acidity indicate 
that the corrosive action of certain vegetables is due to substances of this 
group. 

Influence of Different Weights of Tin Coating.— A committee of the 
National Canners Association, the American Sheet and Tin Plate Company, 
and the American Can Company has reported results of extensive experi- 



VEGETABLE AND FRUIT PRODUCTS. 



965 



ments on the action of various canned foods on cans with tin plate coatings 
of from 0.9 to 3.0 pound of tin per base box. Determinations of tin and 
iron were made at intervals. The figures in the following table show the 
extreme amounts of tin dissolved from the lowest and highest weights of 
plate and during short and long periods. The amounts of iron dissolved 
were more nearly uniform, the maximum being 90 mg. per kilo. 

TIN IN CANNED VEGETABLES AND FRUIT 
Mg. per Kilo 





StringBeans. 


Corn. 


Peas. 


Pumpkin. 


Tomatoes. 


Apples. 




Max. 


Min. 


Max. 


Min. 


Max. 


Min. 


Max. 


Min. 


Max. 


Min. 


Max. 


Min. 


Packed 1^-5 mo. 


























0.9-lb. plate. . . 


97 


75 


13 


3 


32 


9 


82 


31 


175 


42 


166 


34 


3-lb. plate. . . . 


161 


126 


14 


3 


27 


IS 


194 


37 


61 


36 


189 


29 ' 


Packed 105-13 mo. 


























0.9-lb. plate. . . 


220 


154 






26 


12 


476 


44 


148 


S8 


203 


27 


3.0-lb. plate. . . 


338 


174 


... 




26 


14 


824 


174 


ISO 


36 


228 


35 



The committee in its conclusion states: "The lustre and the resist- 
ance to rusting increase somewhat with increased weight of coating. In 
other respects, with the exception of some instances in those classes of 
foods that have a tendency to perforate, the conclusion from this work 
is that the value of different weights of tin coating on food containers 
is for all practical purposes the same with average weights of from i to 3 
pounds of tin per base box." 

Salts of Lead. — ^While it is a fact that the material of the tin plating 
usually found in cans is comparatively low in lead, the same is not always 
true of the metal caps u.sed to cover some of the bottled goods. The 
French "haricots verts "are usually sold in wide-mouthed bottles, closed 
by a disk of very soft metal. In one instance this metal cap, which came 
in contact with the liquid contents of the bottle, was found to contain 
93i% of lead. Of the various kinds of bottles in which are sold cheap 
carbonated drinks known as "pop," one style has a stopper consisting of 
a metallic button surrounded by a rubber ring. These metallic buttons 
consist of tin and lead in varying proportions. Inasmuch as the inclosed 
liquor was usually found to be quite acid in reaction, the danger of pro- 
longed contact with the metallic portion of the stopper is evident. 

The following table gives the percentage of lead found in the stoppers 



966 



FOOD INSPECTION AND ANALYSIS. 



of this character, together with the amount of lead contained in the 
Hquor.* 



Character of Sample. 


Per Cent of 
Lead in Stopper. 


Amount of Lead 
in Contents of 
Bottle in Milli- 
grams. t 


Blood orange 


50-7 
35-0 
32.2 
8.8 
6-5 
8-5 
3-5 
7-5 

50-3 
3-8 


0.31 
Large trace 
0.40 
C.20 
0.30 
0.19 
0.17 
0.27 

1.05 

O.OI 


Birch beer 


Ginger 


Strawberry A 


Strawberry B 




Sarsaparilla B 


Lemon 


Miscellaneous (20 samples) 
Maximum 


Minimum 





t Capacity of bottle about i pint. 

Besides the above tabulated samples, twenty were found with stoppers 
containing less than 3% of lead. While the amount of lead found in the 
contents of the bottles was in no case very large, it was enough to con- 
demn the use of lead in the manufacture of such stoppers. That the 
amounts of lead found in the contents of the bottles vary quite irrespective 
of the percentage of lead in their stoppers, may be ascribed to various 
causes, such as the difference in the acidity of the liquors, and the length 
of time that the liquor has been in contact with the stopper. Furthermore, 
the more soluble metal of an alloy is attacked by an acid with an energy 
which is not proportional to the percentage of that metal in the alloy. 

Salts of Zinc. — The presence of zinc salts in canned foods is largely 
accidental, and is generally due either to the contact of the acid fruits 
and vegetables with galvanized iron in the canneries, to the occasional 
use of brass vessels, or to the zinc chloride used as a soldering fluid. Hil- 
gard and Colby f have examined empty tin cans fresh from the manu- 
facturer, and found zinc chloride in notable quantity in the seams, and 
especially in the empty space of the lap at the bottom of the can, where 
it could easily be acted on by the contents. The average amount of soluble 
zinc chloride found in the " lap " alone amounted to three-fourths of a 
grain per can. It was furthermore ascertained that it was not the practice 
of canners to wash the cans before packing, so that zinc present in canned 
goods may thus readily be accounted for. 

* An. Rep. Mass. State Board of Health, 1897, p. 571. 
t Rep. Cal. Agric. Exp. Sta., 1897-8, p. 159. 



VEGETABLE AND FRUIT PRODUCTS. 967 

Zinc chloride is commonly used in machine soldering, but should be 
displaced by rosin. 

Holgard and Colby found in some spoiled cans of asparagus, where 
the acidity was unusually high, an average of 6.3 grains of zinc chloride 
per large can. 

Zinc salts are said to have been used for greening peas, but their use 
for this purpose is not common. Zinc chloride is the salt used, and a 
natural yellowish-green tint is imparted when properly applied. The 
process has been kept secret. 

Salts of Copper. — While copper in canned goods is sometimes acci- 
dental, its presence being due to the use of copper or brass vessels in the 
canneries, its chief interest to the food analyst lies in the use of copper 
sulphate for greening peas and other vegetables. The artificial greening 
of vegetables is much more commonly practiced in France than in the 
United States. 

French canners of peas, beans, Brussels sprouts, etc., are frequently 
so lavish in the use of sulphate of copper that the goods as found on our 
markets can in some cases hardly be said to resemble the freshly cooked 
products in color. Oftentimes, indeed, they possess such a deep green 
as to be positively distasteful to the average American palate, though 
evidently this unnatural hue is craved in Europe. The use of copper 
in such foods is often rendered apparent by the most cursory examination. 

In this country the use of copper was commonly in smaller amounts 
than in France even before regulations prohibiting its use were adopted. 

Complaint in court for this form of adulteration under the general 
food law as it exists in most states would naturally be brought under one 
of two clauses : 

I St. As being colored, whereby the product appears of greater value 
than it really is, or 

2d. As containing an ingredient injurious to health. 

An ingenious claim is sometimes advanced by the defendant in oppo- 
sition to clause i, to the effect that copper sulphate is added, not to give 
an artificial green color, but to preserve the original green of the chloro- 
phyl or natural color of the fresh peas,* so that it will not be destroyed 
by subsequent boiling. 

This point was argued in a strongly contested court case brought in 
Massachusetts for copper in French peas.f 

* The term used by the French to describe this process is reverdissage or "regreening." 
t An. Rep. Mass. State Board of Health, 1892, p. 605. 



968 FOOD INSPECTION AND ANALYSIS. 

As Worcester * has shown, the fallacy of this argument can be easily 
demonstrated. If it were true that the copper acts as a preservative of 
the chlorophyl, a pure extract of chlorophyl should, by the addition of 
copper sulphate, be prevented from destruction on boiling, and again, 
on once destroying the color of the chlorophyl by boiling, it would be 
impossible to restore it by further boiling it with copper sulphate. 

As a matter of fact, if an extract of chlorophyl is boiled with a dilute 
solution of copper sulphate, its color is at once destroyed, and a brown 
precipitate is thrown down. On the other hand, if yellow or white peas 
or beans devoid of chlorophyl are boiled with copper sulphate, they are 
colored green, the depth of color depending on the strength of the copper 
solution. When peas or other vegetables are thus colored, very little 
copper is found, as a rule, in the liquid contents of the can, but the copper 
is chiefly confined to the solid portions. Green compounds are produced 
by boiling albumins with copper salts, due to the formation of albuminate, 
or in the case of peas, leguminate of copper. Harrington t states that it is 
possible to color eggs an intense green by boiling with copper sulphate. 

Examination of a large number of brands of canned vegetables greened 
by copper, as bought in Massachusetts, showed that the amount used 
varied from a trace to 2.75 grams per can, calculated as copper sulphate. 
In justice to the consumer, who may be cautious about taking into his 
system copper salts, as well as to those who are indifferent to their use, 
it is no more than fair that all cans should have a label, plainly stating 
the quantity present. In the Massachusetts market, labels like the fol- 
lowing are not uncommon: "This package of French Vegetables con- 
tains an equivalent of Metallic Copper not exceeding three-quarters of 
a gram." 

Copper as a coloring matter has been most commonly found in peas, 
beans, and Brussels sprouts. Copper salts in minute quantity have been 
found in Massachusetts in canned tomatoes, clams, and squash, as well 
as in pickles. 

Salts of Nickel. — Sulphate of nickel has been employed instead of 
sulphate of copper for greening vegetables. According to Harrington J 
0.25 gram of nickelous sulphate per kilogram of peas is used. The peas 
or other vegetables are boiled in a solution of the salt, made slightly alka- 
line with ammonia. 

* Loc. cit., p. 641. 

t Practical Hygiene, p. 203. 

t Ibid., p. 205. 



VEGETABLE AND FRUIT PRODUCTS. 969 

Toxic Effects of Metallic Salts. — Divergence of opinion is so great 
as to the toxic effects of salts of the heavy metals on the Jiuman system, 
when present in the small amounts commonly found in food products, 
that it is extremely difhcult to maintain a complaint in court based entirely 
on the harmful effects of these salts. Since the question is one for the 
toxicologist or physiological chemist rather than the analyst to settle, it 
will not be discussed here at length. 

The toxic action of lead salts is too generally recognized to need dis- 
cussion. 

Authorities were not agreed on the toxic action of copper as present 
in coppered vegetable, hence the desirability of experiments such as were 
conducted by the Referee Board of Consulting Scientists.* Their results 
indicate that while as much as 150 mg. of copper may be contained in the 
coppered beans or peas eaten in a day as little as 10 mg. under certain con- 
ditions may have a deleterious action and must be considered injurious to 
health. Accordingly foods greened with copper are considered adulterated 
by the federal authorities. f 

The case of tin is quite different from that of lead and copper, since 
it is an accidental impurity which it is not practicable to eliminate with 
our present knowledge ; furthermore its toxicity is less. Investigations by 
Bigelow X and Goss § show that the tin in canned goods exists usually in 
greater amount as insoluble than as soluble compounds. 

Preservatives. — No class of food products stands so little in need of 
these added substances to arrest fermentation as canned foods, if properly 
prepared and, as a matter of fact, the use of antiseptics has been almost 
entirely discontinued. 

The Bleaching of Com by artificial means before canning is usually 
accomplished by boiling the corn with sodium sulphite, thus giving to 
the product an unnaturally white color. The practice seems to have been 
more in vogue some years ago than at present, the popular taste now appar- 
ently preferring the natural rich yellow of fresh corn. 

Saccharin is claimed to possess antiseptic powers and is used in canned 
goods, but its primary purpose is as a sweetener. 

Salicylic Acid, Sodium Benzoate, and Beta-naphthol, although formerly 
used, are now seldom found in canned goods. 

* U. S. Dept. of Agric, Rep. 97, 1913. 
t Food Inspection Decision 148. 
J Jour. Ind. Eng. Chem., 8, 1916, p. 813. 
§ Ibid., 9, 191 7, p. 144. 



970 FOOD INSPECTION AND ANALYSIS. 

" Soaked Goods."— It has become quite common, especially in the case 
of peas, beans, -and corn, to utilize for canning purposes those that have 
grown old and dried, after soaking them for a long time. The presence of 
soaked peas in the market is generally more common in years when there 
is a scarcity in the pea crop. By the process of soaking, dried and matured 
field corn may be softened to such an extent as to be substituted for green 
or sweet corn in the canned product. These goods, frequently sold at a 
very low price, under some such tempting name as " Choice Early June 
Peas," are entirely devoid of that succulent property so highly prized in 
the fresh goods, and are altogether so inferior in quality that their sale may 
justly be considered as fraudulent, unless their character is specified. 
In some states the law provides that such a product, to be legally sold, shall 
have plainly marked on the label of the can the words " Soaked Goods " 
in letters of prescribed size. 

Detection. — Methods of detecting soaked goods are distinctly physical 
rather than chemical. While chemical analysis may not be decisive, the 
appearance and taste of the goods furnish in most cases an unmistakable 
clue to their nature. Soaked goods are entirely lacking in juiciness, and in 
the flavors so characteristic of the various vegetables, when gathered and 
canned before becoming dry. The process of soaking is also said to 
develop the growth of the rudimentary stem of the embryo in the dried 
pea and bean. Peas and beans of the soaked variety are almost entirely 
lacking in the green color of the fresh vegetables, unless the color has been 
artificially supplied. The lic[uid is commonly milky. 

In all cases it will be found that the solid grains or kernels of the 
peas, beans, and corn that have once been dried, though softened by 
the process of soaking, have much less water than the grains of the cor- 
responding vegetables that were gathered while still soft and succulent. 

METHODS OF ANALYSIS. 

Methods of Proximate Analysis.— These are essentially the same as 
for cereal products with such Nariation in the preparation of the sample as 
is necessitated by the moist condition and lack of uniformity. 

Examination of Gases from Spoiled Cans. — Fig. ii8 shows the 
Doremus apparatus for puncturing the can with a hollow needle and con- 
ducting the gases into a eudiometer, where they are examined by the usual 
methods for gas analysis. Baker in his investigations used in conjunction 
with this apparatus a frame with another puncturing needle through which 



VEGETABLE AND FRUIT PRODUCTS. 



971 



water was introduced under pressure, thus forcing out all the gases through 
the Doremus needle. 

Determination of Drained Solids.— Scarcely two workers have followed 
the same method. The results obtained depend on whether a sieve or 
cheese cloth is used for straining, the size of the mesh, the time allowed 
for draining, and whether or not any pressure is applied. 

Magruder * uses a sieve with i mm. round holes and allows to stand for 
about five minutes, stirring gently with a spatula at the begmning and end. 

McGill t turns out the contents of the can upon a piece of cheese cloth 
of known weight spread upon a sieve 6 inches in diameter and drains for 




Fig. 1 1 8. — Apparatus for Collecting Gases from Spoiled Cans. (After Doremus.) 

approximately two hours without pressure or until drops fall at intervals 
of more than live seconds. 

Ladd,J in addition to a |-inch mesh sieve adopted by the Canners' 
Associations of three states some years since, employs a cheese cloth to 
retain the finely divided matter, a method which, according to Bige- 
low's experiments,! gives 3% to 6% more drained solids than the sieve 
alone. 



* Jour. Assn. Off. Agr. Chem., i, 1915, p. 199. 
t Lab. Inl. Rev. Dept. Canada, Bui. 357, 1916. 
t Jour. Assn. Off. Agr. Chem., 3, 191 7, p. 1. 



972 FOOD INSPECTION AND ANALYSIS. 

Determination of Tin on Tin Plate. — Baker Method.^ — Cut 4 square 
inches of the plate, loosely fold, introduce into a 300-cc. Erlenmeyer flask 
with from 50 to 100 cc. of concentrated hydrochloric acid, and determine 
the tin by the method as described for contents (p. 875), using, however, 
an iodine solution of such strength that, with the size of sample employed, 
10 cc. is equivalent to i pound of tin per base box. 

For the preparation of the iodine solution, dissolve 45 grams of iodine 
and 65 grams of potassium iodide in a small amount of water, dilute to 
4 liters, allow to stand overnight, check against solutions containing a 
known amount of tin and an amount of iron equivalent to that used in a 
sample, and dilute until i cc. = 0.005 786 gram tin. 

Hiltner Method. ■\ — This is a rapid method for the determination of lead 
as well as tin in both tin and terne plate. 

Determination of 'Lead in Tin Alloy. — Method of Paris Municipal 
Lahoratory.X — The material, if soft, is hammered into a thin plate, and 
2\ grams are weighed out, transferred to a 250-cc. flask, and dissolved 
in 7 to 8 cc. of concentrated nitric acid. Evaporate to dryness on the 
sand-bath, add 10 drops of nitric acid and 50 cc. of boiling water, cool, 
and make up to 250 cc. with water. Let the residue settle and pour off 
through a filter 100 cc. of the clear, supernatant liquid, corresponding 
to I gram of the material. This contains the lead, while the tin is left 
behind in the residue, together with antimony if present. 

Add 10 cc. of a standard solution of potassium bichromate (7.13 grams 
to the liter) and shake. Each cubic centimeter of this standard solution 
is sufficient to precipitate 0.0 1 gram of lead. Allow the lead chromate 
formed to settle, and, if the solution is colorless, add 10 cc. more of the 
bichromate, or sufficient to be present in excess, as indicated by the yellow 
color. Filter, wash, and titrate the excess of bichromate with a standard 
iron solution, containing 57 grams of the double sulphate of iron and 
ammonia and 125 grams of sulphuric acid per liter. This iron solution 
should be kept under a layer of petroleum, and standardized against 
the potassium bichromate before use. 

Add, drop by drop, the iron solution to that containing the excess of 
bichromate. The color of the latter passes from pale green to bright 
green, when the chromate is completely reduced. Determine the end- 

* Relative Value of Different Weights of Tin Coating on Canned Food Containers, Nat. 
Can. Assn., Washington, 1917, p. 31. 

t Western Chem. Metal., 4, 1908, p. 262. 

X Girard, Analyse des Matieres Alimentaires, Paris, 1904, p. 829. 



VEGETABLE AND FRUIT PRODUCTS. 973 

point with a freshly prepared dilute solution of potassium ferricyanide, 
a drop of which is placed on a porcelain plate or tile in contact with a 
little of the solution titrated. A blue color is produced when the iron 
is present in excess. If the standard iron and bichromate solutions exactly 
correspond, i cc. of the iron solution is equivalent to i% of lead, but 
the latter solution is usually a little weak. 

If w = number of cubic centimeters of iron solution necessary to reduce 
lo cc. of the standard bichromate, 

I cc. of the iron solution = — . 

n 

If, now, f= number of cubic centimeters of iron solution necessary 
to reduce the excess of bichromate in the determination, and 5= number 
of cubic centimeters of bichromate used, 

s r = per cent of lead in the alloy. 

n 

Separation and Determination of Tin, Copper, Lead, and Zinc in 
Canned Ooo&s.—Mimson's Method/^ — The contents of the can are 
first evaporated to dryness, and from lo to 15 cc. of concentrated sul- 
phuric acid or enough to carbonize are added to the dry residue contained 
in a porcelain evaporating-dish, which is very gently heated over the flame 
till foaming ceases. Then ignite to an ash in a muffle, or carefully over 
the free flame, using a little nitric acid, if necessary, for oxidation of the 
organic matter. Add 20 cc. of dilute hydrochloric acid, and evaporate 
over the water-bath to dryness. Wash the residue into a beaker, slightly 
acidify with hydrochloric acid, and saturate with hydrogen sulphide 
without previous filtration. Heat the beaker on the water-bath, and 
pass the contents through a filter. Wash the precipitate, which contains 
sulphides of tin, lead, and copper, if these metals are present, while if there 
is zinc, it is contained in the filtrate. The precipitate is fused with sodium 
hydroxide in a silver crucible for half an hour, to increase the solubility 
of the tin, which would otherwise be dissolved with difficulty. The 
fusion is boiled up with hot water, acidulated with hydrochloric acid, and 
transferred without filtering to a beaker, in which hydrogen sulphide 
is added to saturation. This precipitates the sulphides of tin, lead, and 
copper (if these metals are present). The sulphide precipitate is collected 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 107 rev., p. 62. 



974 FOOD INSPECTION AND ANALYSIS. 

on a filter, and thoroughly washed with hot water, the washings being 
rejected. Pass through the filter several portions of boiling ammonium 
sulphide, using about 50 cc. in all, or till all the tin is dissolved. Precipi- 
tate the tin from the combined filtrate with hydrochloric acid, filter, 
wash, ignite, and weigh as stannic oxide. 

The residue left on the filter, after dissolving out the tin sulphide, is 
then dissolved by treatment with nitric acid, which is filtered, and to 
the filtrate and washings ammonia is added nearly to the point of neutrali- 
zation. Then add ammonium acetate. Filter off any precipitate of 
iron that may be formed. The filtrate is divided into two portions for 
determination of copper and lead. If lead is absent, determine the 
copper by titration with potassium cyanide * or electrolytically (p. 634). 
Copper is rarely present in sufficient amount to be determined, unless 
used for greening the vegetables. If notable quantities of lead are present, 
the solution is made acid with acetic, and the lead precipitated therefrom 
with potassium chromate, collected on a tared filter, washed with water 
acidified with acetic acid, dried at 100° C, and weighed as lead chromate. 
Or determine the lead by color-tests, as on page 362. 

For the determination of zinc, the filtrate from the first hydrogen- 
sulphide residue is evaporated to a volume of about 60 cc, and treated 
with bromine water to oxidize the iron, as well as any excess of hydrogen 
sulphide remaining, the excegs of bromine is then boiled off, and a few 
drops of concentrated ferric chloride added, to make the solution distinctly 
yellow, if not already so. Nearly neutralize with ammonia, and precipi- 
tate the iron with ammonium acetate. Filter, wash, acidify the filtrate 
with acetic acid, and precipitate the zinc with hydrogen sulphide. Filter, 
wash, ignite, and weigh as zinc oxide. 

The metals may be determined separately, as follows: 

Determination of Tin.f — Evaporate the contents of the can to dry- 
ness, and ignite in porcelain. Fuse the ash with sodium hydroxide in a 
silver crucible, boil the fusion with several portions of water acidulated 
with hydrochloric acid, filter, and precipitate the tin from the acid solu- 
tion with hydrogen sulphide. Dissolve the washed precipitate in ammo- 
nium sulphide, filter, and deposit the tin directly from this solution by 
electrolysis in the platinum dish which contains it, using a current of 
0.5 ampere and the electrolytic apparatus described on page 634. 

* Sutton, Volumetric Analysis, 8th ed., p. 204. 

t Hilger u. Leband, Zeits. Unters. Nahr. Genussm., 2, 1899, p. 795; An. Rep Mass. 
State Board of Health, 1899, p. 625. 



VEGETABLE AND FRUIT PRODUCTS. 975 

Smith and Bartlett * employ the following method of solution : Weigh 
50 grams of fish or 100 grams of vegetables in a porcelain dish and dry- 
overnight. Heat from 75 to 100 cg. of concentrated sulphuric acid in a 
Kjeldahl flask until acid fumes are visible, then add gradually small por- 
tions of the food product, heating the acid between additions until frothing 
ceases. Allow to cool, then add gradually to the charred mixture 25 cc. 
of concentrated nitric acid, which causes the e\olution of red fumes and the 
generation of heat. Cool, add 25 cc. of nitric acid and heat gently until 
all nitric fumes are expelled and the charred material is dissolved to a 
homogeneous solution. Boil this solution about forty-five minutes, then 
add from 10 to 15 grams of potassium sulphate and continue boiling from 
three to five hours until decolorized. Wash the digest into an 8co-cc. 
beaker, dilute to about 600 cc. and bring to a boil. Almost all of the tin 
separates as stannic oxide, partially hydrated, some of which adheres to the 
sides of the flask, and cannot be removed by washing. Filter the contents 
of the beaker, thus separating the hydrated stannous oxide from all other 
compounds. Place the filter in the flask, to which 20 cc. of saturated 
sodium hydroxide and an equal volume of water have been added, boil 
for several minutes, then wash the sodium stannate into a beaker. Acidify 
with hydrochloric acid, precipitate with hydrogen sulphide, and proceed 
as above described. 

Hanson and Johnson j heat a quantity of the material, containing 
about 25 grams of solids, with a mixture of 2co cc. of water, 100 cc. of 
concentrated nitric acid and 50 cc. of concentrated sulphuric acid, adding 
additional nitric acid from time to time and finally 25 grams of potassium 
sulphate. 

Baker Method.X — Treat 100 grams of the material with nitric and 
sulphuric acid as described in the preceding sections. Dilute the sulphuric 
acid residue, neutralize with ammonia, add hydrochloric acid until the 
solution contains about 2*^, and thoroughly saturate with hydrogen 
sulphide gas. Filter the impure lead sulphide on a Gooch crucible with 
a false bottom, wash three or four times with water, then transfer precipitate 
and asbestos to a 300-cc. Erlenmeyer flask, washing with a little water, 
and boil with strong hydrochloric acid, adding potassium chlorate from 
time to time to insure complete solution of the tin sulphide as well as the 
elimination of the sulphur. Add a few strips of pure aluminum foil, 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 134. 
t U. S. Dept. of Agric, Bur. of Chem., Bui. 152, p. 117. 
t 8th Intern. Cong. Appl. Chem., 18, p. 35. 



976 FOOD INSPECTION AND ANALYSIS 

free from tin, until all the chlorine is eliminated, then dilute to from 30% 
to 40% acid strength and attach to a carbon dioxide generator provided 
with a scrubber and charged with pure marble and hydrochloric acid. 

A bulb tube passing through one opening of a double-bore stopper 
serves to deliver the gas near the surface of the liquid and another bulb 
tube provides an exit, the latter being connected with a glass tube immersed 
in water to the depth of 20 cm., forming a water seal. When the flask is 
first attached to the carbon dioxide apparatus, lift the exit tube out of the 
water so as to reduce the pressure and thus force a large amount of gas 
through the system, expelling all air. Then raise the stopper of the flask 
and introduce about i gram of aluminum foil, which quickly reduces the 
tin to the metallic form with evolution of hydrogen. 

Heat to boiling on a hot plate and boil for a few minutes, which causes 
the aluminum to disappear and changes the tin into stannous chloride, 
then cool in ice-water, still passing carbon dioxide through the system. 
Remove the stopper together with the tubes, washing the same and the 
sides of the flask with air-free water, prepared by boiling distilled water, 
adding a small amount of sodium bicarbonate and then a slight excess of 
hydrochloric acid. 

Add starch paste and titrate directly and quickly with hundredth- 
normal iodine solution until a faint blue color is obtained. The iodine 
solution is standardized against pure tin solution or a food mixture, such 
as apple butter, containing an added amount of tin salt. 

An alternate procedure is to add an excess of iodine solution to the 
flask after lifting the stopper, but while the carbon dioxide is still issuing 
from the neck, and titrate the excess with standard sodium thiosulphate 
solution. 

By means of a Y-tube the current from one generator may be divided 
for two flasks so that duplicates may be conducted at the same time. 

Determination of Lead, especially applicable if lead is present in small 
amounts only. Boil the sulphated ash of the contents of the can (obtained 
as on page 973) with a solution of ammonium acetate, having an excess of 
ammonia. The tin, zinc, and iron remain insoluble, while the copper 
and lead are dissolved. Filter, wash, and add a few drops of potassium 
cyanide to the filtrate, to prevent precipitation of copper when hydrogen 
sulphide is subsequently added. If the solution exceeds 40 cc, concen- 
trate to that amount by evaporation, and transfer to a 50-cc. Nessler 
tube. Add hydrogen sulphide water, and make up to the mark. Com- 
pare the brown color imparted by the lead sulphide, with the colors obtained 



VEGETABLE AND FRUIT PRODUCTS. 977 

by treating with hydrogen sulphide water in Nessler tubes various measured 
amounts of a standard solution of lead acetate, made alkaline with ammonia. 
See also page 362. 

Determination of Copper.— (i) Electrolytically.— Ash. the contents of 
the can as on page 973. Wet the ash with concentrated nitric acid, add 
water, and boil. Then make strongly alkaline with ammonia and filter. 
Unless the filtrate is colored blue, copper is absent. Transfer the filtrate 
to a bright tared platinum dish of loo-cc. capacity, neutralize with con- 
centrated nitric acid, and add about 2 cc. in excess. Nearly fill the dish 
with water, and electrolyze with the apparatus described on page 634, 
using a current of about 0.3 of an ampere. 

(2) Colorimetrically. — This method is especially applicable for small 
amounts of copper. The blue-colored ammoniacal solution of the ash, 
filtered as in (i), is transferred to a Nessler tube, and its color matched 
against the colors of a series of measured amounts of an ammoniacal 
standard solution of copper sulphate. 

Determination of Nickel.— Boil the ash with water slightly acidified 
with hydrochloric acid, and without filtering, saturate with hydrogen 
sulphide, thus precipitating out any copper, tin, or lead. Filter and wash. 
Zinc and nickel, if present, are in the filtrate. Boil the filtrate to expel 
the hydrogen sulphide, and add sodium carbonate till slightly alkaline. 
Add acetic acid without filtering till the precipitate produced by the 
alkaline carbonate is dissolved, and then add a considerable excess of 
acetic acid. The zinc is precipitated by passing hydrogen sulphide 
through the cold dilute solution, while the nickel is held in solution by 
the large excess of acetic acid. Filter, and wash with hydrogen sulphide 
water, to which a little ammonium acetate has been added. 

Make the filtrate alkaline with ammonia, precipitate the nickel with 
ammonium sulphide, filter, wash, ignite, and weigh as nickelous oxide. 

KETCHUP. 

Standards. — The following are the United States standards: 
Catchup [Ketchup, Catsup) is the clean, sound product made from the 
properly prepared pulp of clean, sound, fresh, ripe tomatoes, with spices 
and with or without sugar and vinegar; Mushroom Catchup, Walnut 
Catchup, etc., are catchups made as above described, and conform in 
name to the substances used in their preparation. 

No standard is given for Chili Sauce, a product made from tomatoes, 



978 FOOD INSPECTION AND ANALYSIS. 

peppers, onions, vinegar, sugar, and spices, differing from ketchup in that 
it is not strained. 

Process of Manufacture.^When made in the household ripe tomatoes, 
with or without paring and coring, are cut in pieces and boiled down to 
a thick pulp, strained to remove seeds and other coarse tissues and finally 
heated for a time with \inegar, spices, salt, and sugar. The product is 
bottled while hot. 

Factory-made ketchup, of good quality, is prepared by practically 
the same process, using special apparatus for washing, pulping and con- 
centrating. In many factories considerable time elapses before the finish- 
ing processes are carried out, the pulp being stored in barrels or better 
in lacquered tin receptacles until needed. Manufacturers of ketchup 
often purchase the barrelled or canned pulp from canning factories, con- 
fining their attention to the final processes and bottling. 

In the so-called gravity process the pulped material is allowed to stand 
until fermentation sets in and the cellular matter rises to the surface. 
The clear liquid is then removed from below. In Italy it is a common 
practice in the manufacture of tomato paste to allow the pulp to ferment 
for a time, after which the fermentation is checked by the addition of salt.* 

The Composition of Tomato Catsup varies within wide limits due chiefly 
to variations in the composition of the tomatoes, the amount of fibrous 
material removed in screening, the degree of concentration, and the amount 
and composition of the substances added, particularly the vinegar. This 
is shown by the maximum and minimum results for total solids and acidity 
reported in commercial catsups by Winton and Ogden,t Street,J and 
McGill § as given in the following table: 



Winton and Ogden. 

Street 

McGill 



Total Solids. 



42.64-6.03 
32.49-7.27 
38.63-6.66 



Acidity Calc. 
as Acetic. 



2 . 20-0 . 60 
1.98-0.54 
2.85-0.45 



Tomato Catsup from Trimmings. — If instead of the pulp of the whole 
tomato the pulp of trimmings (skins, cores, etc.) from tomato canneries is 

* Daily Consular and Trade Reports, 14, 1911, p. 74. 

t Conn. Agr. Exp. Sta. Rep., 1901, p. 135. 

X Ibid., Rep., 1910, p. 521. 

§ Lab. Inl. Rev. Dept. Canada, Bui. 368, 191 7. 



VEGETABLE AND FRUIT PRODUCTS. 



979 



used another complication is introduced. The presence of trimmings pulp 
obviously cannot be detected by mere determination of solids, even if no 
salt, sugar, or other additions were made, since the percentage of solids 
is dependent in large part on the degree of concentration. Bigelow and 
Fitzgerald* calculated the ratio of pulp solids to filtrate solids and the 
percentage of insoluble solids in the total solids, in the case of whole tomato 
pulp and of trimmings pulp with the following results: 



Ratio of pulp solids to filtrate solids: Maximum 

Minimum 

Per cent of insoluble solids in total solids: Maximum , 

Minimum. , 



Whole Tomato 
Pulp. 




Trimmings 
Pulp. 



I.24it 
i.iogt 
i4-7§ 
"•4§ 



* 30 samples. 



t 18 samples. 



t 24 samples. 



§ 7 samples. 



These results do not sharply differentiate the two products and after 
the addition of the other constituents proper to tomato catsup the dis- 
tinction would be still less marked or entirely absent. 

The use of tomato trimmings for cheap catsup appears unobjectionable 
provided they are from sound tomatoes and have not been allowed to spoil. 
Too often the material is objectionable. This is especially the case when 
the product is improperly stored and too long a time elapses before its 
manufacture into catsup. 

Decayed Material. — According to Bacon and Dunbar f fresh tomatoes 
contain on the average 6.5% total solids, of which 3.5% is invert sugar, 
0.5% citric acid, 0.6% ash, 0.9% protein (NX6.25), 0.85% crude fiber 
and 0.05% fat. During spoilage the sugars rapidly disappear, forming 
alcohol, carbon dioxide, acetic and lactic acids, the amounts of each 
formed depending on the organisms present. Usually the citric acid is 
also decomposed. A good ketchup is accordingly characterized by a 
high citric acid content and little lactic acid, while one made from decom- 
posed material will usually contain little or no citric acid, but a high per- 
cent of lactic acid. 

Bitting and Bitting J state: " The procedure in determining wholesome- 
ness is different from that for sterility, as in ihe former one must deal with 

* Jour. Ind. Eng. Chem., 7, 1915, p. 602. 

t U. S. Dept. of Agric, Bur. of Chem., Circ. 78. 

t Natl. Can. Assn. Res. Lab. Bui. 14, 191 7. 



980 FOOD INSPECTION AND ANALYSIS. 

the dead organisms, and is limited almost wholly to what may be seen under 
the microscope. It is most unfortunate that no satisfactory method has 
been developed to determine the presence of unfit material, as the pur- 
chaser has no means of judging from looks, taste, or smell what may have 
entered into these comminuted products. In the whole or large piece 
stock, he can judge by the gross appearance with a fair degree of accuracy. 
We are lacking in the fundamentals necessary for a proper examination: 
that is what constitutes the normal flora upon fully matured products, the 
abundance to which they attain under varying conditions, and what organ- 
isms cause the changes which are generally recognized as decomposition." 

Howard in the examination of catsup under the federal law counts 
(i) rod-shaped bacteria (but ignores micrococci), (2) yeast cells and yeast 
and mold spores together (radically different bodies), and (3) number of 
fields containing mold filaments exceeding one-sixth the diameter of the 
field (i.e., determines the subdivision and distribution, rather than the 
amount of filaments). Details are described in government publications; * 
criticisms are given by Bitting and Bitting, | Prescott, Burrage, and Phil- 
brick,! and Tanner. § 

Foreign Pulp. — Pumpkin pulp and apple sauce, the latter made often 
from unsound material or even pomace, have been extensively used in 
cheap ketchups. At the present time such compound sauces are usually 
labelled to show the constituents present. 

Preservatives. — Salicylic acid, formerly used in most commercial 
ketchup, more recently has given place to benzoate of soda. Bitting || 
has shown that by using sound tomatoes and exercising proper care in 
the process of manufacture, ketchup can be kept without a preservative. 
Manufacturers themselves have corroborated this, many of the standard 
brands being entirely free from any antiseptic material other than spices 
and vinegar. 

Artificial Colors. — Of ninety-four samples of ketchup examined in 
1 90 1 in Connecticut all but fifteen contained coal-tar colors.^ This 
practice, however, is now decreasing and is indeed quite unnecessary if 

* Howard and Stephenson, U. S. Dept. of Agric, Bui. 581, 1917; Howard, Bur. of Chem., 
Circ, 68, 1911. 

t Natl. Can. Assoc. Res. Lab. Bui. 14, 1917. 

X Abs. Bact., I, 1917, p 51. 

§ Bacteriology and Mycology of Foods, New York, 1919, pp. 515, 519. 

|| U. S. Dept. of Agric, Bur. of Chem., Bui. 119, 1909. 

\ Conn. Agr. Exp. Sta. Rep., 1901, p. 135. 



VEGETABLE AND FRUIT PRODUCTS. 981 

fresh ripe tomatoes are used, dark-colored spices are avoided, and sugar 
is not added until the end of the process. 

METHODS OF ANALYSIS. 

The methods described under this head, except those for solids by 
calculation, may be used for tomato catsup, chili sauce, tomato pulp, 
fresh tomatoes, and canned tomatoes, provided the material is suitably 
sampled. 

Determination of Specific Gravity. — Bigelow and Fitzgerald * in order 
to remove air bubbles unavoidably mtroduced in pouring into the picrom- 
eter, centrifuge at looo revolutions per minute, add more of the material 
to volume, and repeat the centrifuging until there is no more contraction. 

Ash, Alkalinity of Ash, and Sodium Chloride are determined by the 
methods described for jams and jellies (page 996) . Volatile Acids, as acetic, 
is determined by the method described for vinegar (page 797). Tests for 
Preservatives and Colors are carried out as described in Chapters XV 
and XVI. 

Determination of Solids. — Weigh 10 grams of the sample into a flat- 
bottomed metal dish 6 cm. in diameter, add water to distribute the mate- 
rial, evaporate to dryness, dry four hours at the temperature of boiling 
water, and weigh. 

Determination of Insoluble Solids.f — Shake 20 grams of the material 
with hot water in a narrow cylinder, centrifuge and decant the clear liquid 
on a tared filter-paper and filter with the aid of suction. Repeat the 
operation several times, finally transferring the material to the paper. 
Finish the washing on the paper and dry at 100° C. to constant weight. 

The filtering may be carried on to advantage on a Buchner funnel, 
using two or more tared filters, as the suction is liable to break a single 
layer. 

Determination of Sand.f — Weigh 100 grams of the well-mixed sample 
into a 2- or 3 -liter beaker, nearly fill the beaker with water, and mix the 
contents thoroughly. Allow to stand five minutes and decant the super- 
natant liquid into a second beaker. Refill the first with water and again 
mix the contents. After five minutes more decant the second beaker into 
a third, the first into the second, refill and again mix the first. Continue 
this operation, decanting from the third beaker into the sink until the 

* Jour. Ind. Eng. Chem., 1915, 7, p. 602. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 152, 191 2. 



982 FOOD INSPECTION AND ANALYSIS J 

lighter material is washed out from the ketchup. Then collect the sand 
from the three beakers into a tared Gooch crucible, dry, ignite, and weigh. 

The method for the determination of ash insoluble in hydrochloric 
acid is not applicable to the determination of sand in tomato products, 
owing to the small amount and uneven distribution. Even when loo 
grams are used the results are far from concordant. 

Determination of Soluble Solids. — Subtract the percentage of insoluble 
solids from the percentage of total solids. 

Determination of Reducing Sugars. — Direct. — Place lo grams of the 
ketchup in a loo-cc. flask, add an excess of normal lead acetate, make 
up to the mark and filter. To the filtrate add powdered sodium sulphate 
or carbonate sufficient to precipitate the excess of lead and again filter. 
Determine the reducing powder of the filtrate by the Munson and Walker 
method (p. 622) and calculate as invert sugar. 

After Inversion. — Mix 50 cc. of the solution, after clarifying and removal 
of the lead, as described in last paragraph, with 5 cc. of concentrated hydro- 
chloric acid, invert in the usual manner (p. 611), nearly neutralize with 
sodium hydroxide and determine the reducing power as before inversion. 

Determination of Acidity. — Bigelow and Fitzgerald Method.^ — Dilute 
20 grams of the material with at least 200 cc. of water, add 0.5 cc. of 1% 
phenolphthalein solution in alcohol, and titrate with N/io sodium 
hydroxide solution. Add i cc. of N/io hydrochloric acid, heat quickly 
to boiling, boil one minute to expel carbon dioxide, cool, and titrate back 
with the standard alkali. 

One cc. of N/io alkali is equivalent to 0.0064 gram of citric acid. 

Determination of Citric Acid. — Bacon and Dunbar Method.* — Weigh 
25 grams into a 250-cc. beaker, make up to approximately 200 cc. with 
95 per cent alcohol, allow to stand with frequent stirring for four hours, 
filter through a folded filter and wash with 50 cc. of 80% alcohol. To 
the filtrate add sufficient water to dilute the alcohol to 50% or 60% and 
then add 10 cc. of 20% barium acetate solution, stir well with a glass rod, 
and allow to stand overnight. In the morning filter on a Gooch crucible, 
washing with 50% alcohol, dry for from three to four hours in an oven 
at 100° C. and weigh. Weight of precipitate times 0.51 equals anhydrous 
citric acid. This method is not applicable in the presence of malic acid, 
hence if apple pulp is a constituent of the ketchup, the Pratt method 
(page T009), should be employed. 

* Loc. cit. 



VEGETABLE AND FRUIT PRODUCTS. 



983 




© 



E:,3J 



/ 



"^ 



Determination of Lactic Acid. — Bacon and Dunbar Method* — To 
loo grams of ketchup add lo cc. of 20% normal lead acetate solution, 
make up to 500 cc, shake well and centrifuge. To 400 cc. of the clear 
portion add a moderate excess of sulphuric acid, 
filter, wash the precipitate with a small amount of 
water, and evaporate the filtrate on the steam bath 
to about 100 cc. Extract for from eighteen to twenty 
hours in a liquid extractor (Fig, 120) with washed 
ether. In case the quantity of lactic acid present 
is greater than 0.5 gram it is usually necessary to 
extract for a longer period. In any case it is well 
to re-extract for from eight to ten hours to make 
sure that the extraction is complete. Ether suf- 
ficiently pure for this purpose may be prepared by 
shaking out ordinary ether once with a sodium hy- 
droxide solution and then ten times with small quan- 
tities of water. Evaporate on a steam bath until the 
ether is no longer evident, and take up the residue at 
once in water and filter, thus removing a small 
amount of coloring matter and substances other 
than lactic acid, which may be extracted from ketchup 
by ether, but which are insoluble in water. Heat the 
filtrate on the steam bath for some time to remove 
all traces of ether or alcohol. Add approximately 
3 grams of sodium hydroxide and 50 cc. of a 1.5% 
solution of potassium permanganate from a pipette. 
Heat on a water-bath at 100° C. for one-half hour. 
At the end of that time, or before, if the color is 
not a decided blue-black or purple, but is green or 
colorless above the layer of brown precipitate, add 
more standard permanganate until, after heating 
one-half hour on a boiling water-bath, the color is 
a blue-black or purple. The oxidation is then 
complete. Make the hot solution strongly acid 
with 10% sulphuric acid (about 50 cc.) and run in 5% standard oxalic 
acid from a burette until the solution is decolorized. Titrate back any 
slight excess of oxalic acid with the standard permanganate solution. 



\ 



Fig, 120. — Bacon and 
Dunbar Extractor for 
Liquids. A, jacket- 
flash; B, extract-tube; 
C, funnel-tube; D, 
condenser. 



*Loc cit. 



984 FOOD INSPECTION AND ANALYSIS. 

(Any standard permanganate and oxalic acid solution may be used within 
reasonable limits of strength.) 

In alkaline solution the permanganate oxidizes the lactic acid quan- 
titatively to oxalic acid according to the equation : 

2C3H603 + ioKMn04=2(COOH)2+4H20+2C02+5Mn02+5K2Mn04. 

Then in acid solution, the oxalic acid is further oxidized by the per- 
manganate to carbon dioxide and water according to the equation : 

5(COOH)2 + 2KMn04+3H2S04=ioC02+8H20+K2S04 + 2MnS04. 

To determine the total weight of permanganate used in the oxidation 
of the lactic acid subtract the permanganate equivalent of the oxalic 
acid used from the total amount used. The weight of permanganate 
times 0.237 equals the weight of lactic acid. 

Microscopic Examination for Foreign Pulp. — Apple is identified by 
the window-like cells of the skin, the pitted vessels of the bundles, quite 
unlike the vessels of the tomato, and the tissues of the core. Pumpkin 
may be detected by the yellow skin of the fruit with colorless stomata, 
somewhat obscure latex tubes and the peculiar cactus-like parenchyma 
of the seeds. Although only the fruit pulp is used, fragments of the skin 
and seeds of sufficient size to be of diagnostic importance often find their 
way into the product. 

PICKLES. 

A large variety of vegetables and fruits are preserved in the form of 
pickles in vinegar, either with or without spices, and kept in wooden 
pails, stoneware pots, kegs, or sealed wide-mouthed bottles. The con- 
tainers are not of necessity air-tight. The commoner vegetables are 
usually pickled without cooking, while fruits such as peaches, pears, 
gooseberries, etc., are usually cooked, or at least heated. Analyses of 
pickles and relishes appear in the table, page 985. 

Cucumber Pickles are the most common, and are prepared by soaking 
the fresh cucumbers in strong salt brine. They are then dried on frames, 
and afterwards treated with boiling vinegar, to which spices may or may 
not be added. Other vegetables pickled in similar manner, either sepa- 
rately or in mixture with cucumbers or " gherkins " to form " mixed 
pickles," are cauliflower, bean pods, white cabbage, young walnuts, and 
onions. 



VEGETABLE AND FRUITS PRODUCT. 



985 



Such soft vegetables as young podded beans and beets are not treated 
with brine, but, after soaking in water, are directly treated with vinegar. 
The vinegar used for the finest pickling is of the cider, wine, or malt 
variety. Cheaper varieties of pickles are put up in " white wine " or 
spirit vinegar. 

Mustard Pickles. — These differ from plain vinegar pickles in the char- 
acter of the preserving medium, which in this case consists of a mixture of 
mustard and spices with the vinegar to form a thin paste. 

Piccalilli consists of a mixture in vinegar of various chopped vege- 
tables, such as cucumbers, cauliflower, onions, green tomatoes, and various 
spices. 

Olives for pickling are picked before they have fully ripened, and 
the inherent bitter taste is removed by soaking in a solution of potash 
and lime. This is replaced by cold water, and finally the olives are 
transferred to the medium in which they are bottled, which con- 
sists of salt brine, either with or without flavoring. The flavoring 
materials employed consist of such substances as fennel, coriander, 
laurel leaves, and occasionally vinegar. Ripe olives in brine are also 
highly esteemed. 

Capers.— TYiQ^Q are the flower buds of the shrub Capparis spinosa, 
which are pickled in vinegar. Nasturtium seeds, when similarly pickled, 
possess a flavor much resembling capers, but their substitution for 
capers could readily be detected by their distinctive appearance, even if 
colored. 

Composition of Pickles and Relishes. — The following table is derived 
from Atwater and Bryant's compilation: 



CHEMICAL COMPOSITION OF KETCHUP, PICKLES, 


AND RELISHES.* 




Number 

of 
Analyses 


Refuse. 


Water. 


Protein. 


Fat. 


Total 
Carbo- 
hydrates 


Ash. 


Fuel 

Value 

per 

Pound. 


Tomato ketchup 


2 
2 


27.0 
19.0 


82.8 
86.4 

58.0 
42-3 

64-7 
52-4 
92-9 
93-8 
77-1 


1-5 
1.4 

i-i 
.8 

1-7 
1.4 

-5 
I.I 

•4 


.2 

.2 

27.6 
20.2 

25-9 
21.0 

-3 
-4 
.1 


12-3 

II. 6 
8-5 

4-3 
3-5 
2.7 
4.0 
20.7 


3-2 
1-5 

1-7 
1.2 

3-4 

2-7 

3-6 

■7 

1-7 


265 
230 


Olives, green: 

Edible portion 

As purchased 

Olives, ripe: 

Edible portion 

As purchased 

Cucumber pickles 

Mixed pick ;S 


1,400 
I)025 

1,205 

975 

70 

no 


Spiced pickles 


395 



* U. S. Dept. of Agric, Office of Exp. Sta., Bui. 28, p. 70. 



986 FOOD INSPECTION .\XD AN.\LYSIS. 

Adulteration. — Pickles were formerly greened in the household by the 
use of copper kettles and in the factor}- by the addition of copper sulphate. 

For methods of detection and estimation of copper, see page 634. 
Pickles may be greened by boiling with much less harmful substances 
than copper salts, such, for example, as grape leaves, spinach, or parsley. 

Free Sulphuric Acid has been found in a number of cases in the \ine- 
gar of pickles bought on the [Massachusetts market. A pronounced 
test for chloride with nitrate of silver should not be attributed to free 
hydrochloric acid, since it may be due to the salt from the brine in which 
the pickles have been treated. 

Alum is sometimes added to the salt solution to produce hardness 
and crispness in pickles. A number of samples of cucumber pickles 
have been found by the author to contain alum. For its detection, fuse 
the ash of the pickles, if free from copper, in a platinum dish with sodium 
carbonate, extract with boiling water, filter, and add ammonium chlo- 
ride. A flocculent precipitate shows alimi. 

Sodium Benzoate and Saccharin have been frequently detected in sweet 
pickles. 

Horseradish. — This condiment is prepared by grating the root of 
the perennial herb Nasturtium armoricia, and preserving in vinegar. 
It is xery pungent and aromatic when first prepared, but by exposure to 
light and air quickly loses strength. Turnip pulp is used as an adulterant. 

PRESERVES. 

Under this head are included various fruit products prepared \vith 
sugar syrup and often also with spices and vinegar. Some of these prod- 
ucts differ little from canned fruits white others are really sweet pickles. 
Mince meat, although not strictly a fruit product, and fruits in cordials 
are classified for convenience as preserves. Jams are considered with 
jelHes in the next section, as are also methods of analysis. 

Fruit Butter.— According to the U. S. Standard, " fruit butter is the 
sound product made from fruit juice and clean, sound, properly matured 
and prepared fruit, evaporated to a semi-solid mass of homogeneous 
consistence, with or without the addition of sugar and spices or vinegar, 
and conforms in name to the fruit used in its preparation."' 

Apple Butter is the best-known product of this class. Unfortunately 
it is sometimes made from decayed fruit or even from apple pomace. 
Glucose is frequently substituted wholly or in part for sugar, in which 
case its presence should be declared on the label. 



VEGETABLE AND FRUIT PRODUCTS. 987 

Mince Meat. — As prepared in the household, mince meat, the fiUing 
for mince pies, contains from lo to 20% of lean meat and about twice 
as much apple. Other constituents appear in the following typical for- 
mula with statement of quantities in parts by weight: 2 parts each of 
meat, raisins, dried currants, and sugar, 4 parts of apples, i part each of 
suet and candied citron, 2 parts of sweet cider, wine or brandy, i to 2 
parts of seasoning including salt, spices, and lemons or oranges. 

Standard Mince Meat of the A.O.A.C. and the Association of State and 
National Dairy and Food Departments, " :*s a mixture of not less than 10% 
of cooked comminuted meat, with chopped suet, apple and other fruit, salt, 
and spices, and with sugar, syrup, or molasses, and with or without vinegar, 
fresh, concentrated, or fermented fruit juices, or spirituous Hquors." 

Adulteration. — There has been some conflict between food officials 
and certain manufacturers as to the proportion of meat in commercial, 
mince meat, the manufacturers clauning that 10% is too much for the 
proper keeping of the product, the food officials, on the other hand, con- 
tending that the manufacturer has no right to lower the recognized standard 
of the housewife. 

As a matter of fact the greater part of the mince meat on the market 
contains considerably less than 10% of meat and much of it none what- 
ever. Glucose is a common substitute for part of the sugar, wormy or 
other inferior fruit is sometunes used, and benzoate of soda is added as 
a preservative. 

Condensed Mince Meat is made in a commercial way from dried 
apples and other desiccated materials and is sold in compressed cakes 
with instructions for preparing from the cakes moist pie filling. As in 
the case of wet mince meat, glucose, wormy fruit and benzoate of soda 
are frequent admixtures and true meat is often omitted entirely. Wheat 
or rye flour is a common adulterant. 

Examination of Mince Mga/.— Meat and cereal flour may be identified 
by microscopic exammation. Care should be taken not to confuse apple 
starch, which is always present m the immature fruit, with cereal starches. 
Meat fibers are recognized by their yellow brown color, the delicate trans- 
verse striations and their occurrence in bundles. 

Determinations of nitrogen are of service in estimating the amount 
of meat present. Glucose and sugar are calculated from the polarization 

readings. 

Pie Filling. Bakers and hotel cooks are supphed by manufacturers with 
filling prepared ready for use in pies. This material is shipped in pails or 



988 FOOD INSPECTION AND ANALYSIS. 

tubs preserved with benzoate of soda, and may contain fruit of questionable 
quality as well as admixtures such as starch, glucose, and artificial colors. 

Maraschino Cherries. — This name has been applied indiscriminately 
to the vivid red preserved cherries used in cocktails, punches, ice cream 
and confectionery. Investigation by the Board of Food and Drug 
Inspection has led to the decision * that only marasca cherries, preserved 
in true maraschino cordial prepared by fermentation and distillation 
from marasca cherries, are entitled to the name maraschino cherries, 
although cherries of other types preserved in pure maraschino cordial 
may be labelled : "Cherries in Maraschino." Ordinary cherries preserved 
in syrup flavored with maraschino may be so labelled, but if the flavoring 
is oil of bitter almonds or benzaldehyde the product should be labelled 
as an imitation if the word maraschino is used. 

Enormous quantities of white cherries of the Bigarreau or Royal 
Anne type, preserved in a mixture of sulphurous acid and brine, are 
brought into the United States from Europe and transformed into red 
" Maraschino cherries " or green " Creme de menthe cherries." After 
removal of the sulphurous acid and brine the cherries are put through a 
dye bath and then, being quite without taste, are flavored with oil of bitter 
almond or benzaldehyde, or else peppermint, and packed in syrup. 
Scarcely more than the cellular structure of the original cherry remains, 
the fruit juice with its sugars, acids, and true cherry flavor being replaced 
by the syrup with its sickening flavor and aroma. Even if flavored with 
true maraschino the metamorphoses through which the fruit passes leave 
it a sorry substitute for the natural cherry. 

Woodman and Davis f have shown that true maraschino contains 
very little benzaldehyde and that cherries flavored with maraschino 
should not contain more than two or three times as many milhgrams of 
benzaldehyde per loo cc. as there are grams of alcohol in that volume, 
and those containing over 20 mg. of benzaldehyde but no alcohol are 
evidently entirely artificial. 

Artificial colors, sulphurous acid and other preservatives are detected 
by the methods given in the chapters on colors and perservatives, benzalde- 
hyde by the following method : 

Determination of Benzaldehyde in Maraschino Cherries. — Woodman 
and Davis Method.f — Reagent. — Mix 3 cc. of glacial acetic acid with 

* Food Inspection Decision 141. 

t Jour. Ind. Eng. Chem., 4, 191 2, p. 588. 



VEGETABLE AND FRUIT PRODUCTS. 989 

40 cc. of water, add 2 cc. of C.P. phenyl hydrazine, as near colorless as 
possible, shake thoroughly, and filter the emulsion through several thick- 
nesses of filter-paper. The clear filtrate should be used immediately 
as a turbidity appears on standing longer than five minutes. 

Process. — Dilute 100 cc. of the liquor from maraschino cherries (or 
50 cc. of maraschino liqueur) to 140 cc. and distill off iiocc. Determine 
approximately the alcohol in the distillate by the pycnometer or immersion 
refractometer, then without delay transfer 100 cc. to a 300 cc. Erlenmeyer 
flask and add alcohol or water so that the solution shall contain approx- 
imately 10% of alcohol. Add 10 cc. of the reagent, stopper tightly with a 
rubber stopper, and shake vigorously for ten minutes. Collect the precipi- 
tate in a tared Gooch crucible, wash with cold water and finally with about 
10 cc. of 10% alcohol. Dry in a vacuum desiccator for 20-24 hours at 
about 20 cm. pressure, or in a vacuum oven at 70-80° C. for 3 hours. 
Throughout the process avoid exposure of the precipitate to strong light. 

Run a blank determination at the same time and deduct the weight 
obtained from that found in the actual analysis. Multiply the corrected 
weight of the precipitate by 0.541 1, thus obtaining the weight of benzalde- 
hyde. 

JAMS AND JELLIES. 

Jams or marmalades are prepared from the pulp of fmits, and jellies 
from the fruit juices. Both jams and jellies, to be considered of the highest 
degree of purity, should contain nothing but the fruit pulp or juice named 
on the label, mixed with pure cane sugar, and, in the case of jams, the 
further addition of spices and flavoring materials is permissible. 

For the manufacture of jam, apples, quinces, and pears are peeled, 
freed from cores, and sliced; berries are simply stemmed; and stone fruits, 
such as peaches and apricots, are peeled, and freed from stones. The 
material, properly prepared, is cooked with as much water as is necessary 
for boiling, and with the addition of an amount of sugar varying with 
different manufacturers. Some prefer to use equal parts of sugar and 
fruit, others one part sugar to two parts fruit. 

In the case of jelly, the fruit is cooked in a small amount of water 
till soft, transferred to a bag or press, and the juice allowed to flow out 
spontaneously, or is squeezed out under pressure, according to the grade 
of jelly desired, the clearest and finest varieties being made from the 
juice that flows out naturally. This juice is then evaporated down with 
the addition of sugar to a density of from 30° to 32° Be., which is of the 



990 FOOD INSPECTION AND ANALYSIS. 

proper consistency to form a perfect jelly product after cooling, and, while 
still hot, is poured into the tumblers in which it is to be kept. Here, as 
in the case of jams, the amount of sugar varies, some using pound for 
pound, and others only half as much sugar as fruit. Some manufacturers 
clarify their jellies by mixing with the juice, while boiling, elutriated 
chalk, using a teaspoonful to each quart of juice. The impurities come 
to the surface with the chalk as a scum, and are skimmed off. This 
clarifying process is somewhat analogous to the defecation of sugar juhes 
with lime, and is commonly carried out with apple jelly. 

The "jellying" or gelatinizing of the final product is due to the presence 
in the fruit juice of pectin, or so-called vegetable jelly (C32H40O284H2O), 
formed by the hydrolysis of pectose. 

The high content of added sugar in jelly, once thought to be essential 
for keeping it, is now no longer considered necessary, and much less sugar 
is at present added than formerly. The finest grade of apple jelly, for 
instance, is made without any added sugar whatever. 

In making the better grades of apple jelly, apple juice fresh from the 
press is run directly into the boiler or evaporator before any fermentation 
has ensued, and gelatinized by concentration. If boiled cider is wanted 
instead of jelly, it is drawn off at an earlier stage than in the case of apple 

jelly- 
Composition of Known-purity Jellies and Jams. — In the tables on 
pages 992 and 993, due to Tolman, Munson, and Bigelow,* are given results 
reached in the examination of the pure finished products, as well as of pure 
fruit juices and pulp used in their manufacture. 

Imitation Jams and Jellies. — Only a small percentage of the products 
sold in the United States belong in the same class with home-made jams 
and jellies consisting exclusively of the fruits in mixture with cane sugar. 
The cheap substitutes are made up largely of apple juice and commercial 
glucose, sometimes containing no fruit whatever of the kind specified on the 
label. Sometimes an attempt is made to imitate the flavor by the addition 
of artificial fruit essences, but more often the same apple-glucose stock 
mixture of jelly, put out under a particular brand, serves to masquerade 
as damson, strawberry, raspberry, currant, grape, etc., differing from each 
other only in color, but not as a rule in flavor. A variety of artificial 
colors are employed, mostly coal-tar dyes. To compensate for the lack 

of sweetness of the glucose, a minute quantity of one of the concentrated 
, 

* Jour. Amer. Chem. Soc, 23, 1901, p. 349. 



VEGETABLE AND FRUIT PRODUCTS. 991 

sweeteners, such as saccharin or dulcin, is sometimes added. Besides arti- 
ficial colors, antiseptic substances are occasionally used, especially sodium 
benzoate. 

All grades of apple stock are found in these preparations. A large 
source of supply is furnished by the parings and cores of canning estab- 
lishments, to say nothing of the refuse of these factories, such materials 
being boiled with water, and the extract, variously colored to imitate the 
different fruits, being evaporated with commercial glucose. 

Imitation Jellies. — While it is easy to make an excellent apple jelly 
by simple evaporation of the pure apple Juice, even without the addition 
of sugar, it is impossible, or at least difhcuU, to obtain the proper degree 
of stiffness wi.h a mixture of apple stock and commercial glucose. It is 
customary, in the manufac.ure of cheap jellies, therefore, to employ 
what is technically termed a " coagulator." Formerly sulphuric acid, 
sometimes with addition of alum was used, but at present phosphoric 
acid is preferred. Citric or tartaric acid is also used for this purpose, 
as well as to increase the acidity. Less than i% of acid will cause the 
mass to gelatmize satisfactorily. 

The lowest grade of apple jelly is made from the exhausted pomace, 
left as a residue after pressing out the juice for cider. Such stock is com- 
monly mixed with water, and boiled down with glucose. Having been 
exhausted of its malic acid, pectose, and other soluble constituents, it 
lacks much of the flavor inherent in pure apple jelly. Various foreign 
gelatinizing agents are found in cheap jellies and preserves, such as 
starch, gelatin, and agar-agar. In the low-priced goods, starch paste 
has been employed. It should be remembered that starch exists in unripe 
apples, but hardly at all in the mature fruit, so that while mere traces of 
starch in jelly may be due to the use of green apples, its presence in large 
amounts is undoubted evidence of the admixture of starch paste. 

Imitation Jams. — Most of the cheap jams and bottled preserves 
sold on the market, though reinforced wi.h apple stock, do in reality 
contain masses of fruit and berries of the kind stipulated on the label, as 
even a casual megascopic examination will show. That such low-priced 
preparations really contain genuine fruit pulp is not to be wondered atj 
when it is considered that much of the virtue of this fruit has sometimes 
been previously extracted by boiling, to produce fruit juices for higher- 
priced goods. Or, as in the case of jams containing strawberries, rasp- 
berries, and other small fruits with seeds, the juice is apt to have been 
previously expressed for pure jellies, while the residues are afterwards 



992 



FOOD INSPECTION AND ANALYSIS. 



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994 FOOD INSPECTION AND ANALYSIS. 

worked up with apple stock for low-priced jams. Hence the presence of 
pure fruit stock, or genuine berry seeds and pulp in jams, is in itself no 
criterion of purity, and furthermore, it is unnecessary to use hay seed and 
other alleged foreign seeds as adulterants of cheap jam. 

Compound Goods. — Many states have a law legalizing the sale of 
"compound" goods, providing they are distinctly so labeled. In other 
states, as, for instance, Massachusetts, the label must plainly state the name 
and percentage of the ingredients. In either case the analyst must 
discriminate, in classifying the inferior or low-grade preparations, between 
those that are labeled in accordance with the law, and those that are not. 
Only those not properly labeled can in such cases be classed as adulter- 
ated within the meaning of the law. Where such a law prevails, probably 
no class of food-producls is so extensively affected by it as the low-grade 
jams, preserves, and jellies. 

The restrictions as to labeling do not in all cases eliminate the element 
of deception. It is hardly justifiable, for example, to boldly label an 
alleged "currant jelly" which contains no currant, in the following man- 
ner: 

Fruit juice 25% 

Cane sugar 14% 

Corn syrup 61% 

100% 

The use of the term "fruit juice" surely implies to the unsuspecting 
purchaser that so much pure currant juice has entered into the jelly, else- 
where labeled in large letters " Currant," whereas all the juice is apple, 
and no currant juice has been used. 

The following label is a type of those which discriminate between pure 
fruit and apple juice: 

Fruit 30% 

Corn syrup 35% 

Granulated sugar 15% 

Apple juice 20% 

100% 

Composition of Cheaper Grades. — Out of 66 samples of jellies, jams, 
and preserves analyzed by Winton, Langley, and Ogden in Connecticut, 
the samples being purchased in that state,* 17 samples contained starch 

* An. Rep. Conn. Exp. Sta., 1901, p. 130. 



VEGETABLE AND FRUIT PRODUCTS. 



995 



paste, 35 were artificially colored with coal-tar dyes, and 19 contained 
salicylic or benzoic acid. 

The following table has been compiled, showing the sugar content of 
some of the typical commercial jellies and jams analyzed in the laboratory 
of the Massachusetts State Board of Health. Nearly all of these were 
artificially colored, and found to contain little if any fruit, other than apple. 



JELLY. 

Apple 

Currant A 

B 

Grape 

Peach 

Pineapple 

Raspberry 

JAM. 

Damson A 

B 

Apricot 

Quince 

Raspberry A 

B 

C 

Pineapple 

Strawberry A 

B 



Direct 
Polariza- 
tion. 



+ 64.0 

+ 29.2 

+ 41-6 

+ 62.0 

+ 119. 8 

+ 114. o 

+ 112.0 



+ 107.0 
+ 95-2 
+ 99.0 

+ 49-6 
-f 123.6 
+ 77-6 
+ 66.0 
+ 119. 8 
+ 41-8 
+ 83.6 



Invert Polarization. 



At 20° C. 



+ 28.0 
+ 20.0 
+ 33-9 
+ 34-4 
+ 108.8 
-f 107.6 
-1-92.0 



+ 94-4 
+ 90.9 

+ 93-5 

+ 43-6 

+ 119. 2 

+ 65 . 1 

+ 29-5 
4-108.8 

+ 21-3 
+ 72.0 



At 87° C. 



+ 36.0 
+ 36.4 
+ 40.8 
+ 46.0 
-f- IIO.O 
+ IIO.O 

+ 93-6 

+ S8.i 
+ 83.6 
+ 85.6 
+ 42.0 
+ 102-5 
+ 46.9 
+ 37-2 

-f- IIO.O 

+ 32-6 

+ 78.8 



Per Cent 
Sucrose. 



26.8 
6.9 

5-7 

20.6 

8.2 

4.9 

14.9 



15 



Per Cent 

Commer- 
cial 
Glucose. 



22.1 
22.3 
25.0 
28.2 
67.4 
67.4 
57-4 

35-6 
51.2 
52-4 
25-7 
62.8 
28.7 
22.8 
67.4 
20.0 
48.3 



METHODS OF ANALYSIS. 

As in the case of canned goods, but little information is to be derived 
as to adulteration of jams, jellies, and preserves by the ordinary deter- 
minations of moisture, ash, and nitrogen, and these are rarely made by 
the public analyst. 

Of considerable importance in this regard, however, are the sugar 
determinations, made with a view to ascertaining the varieties of sugar 
employed, as well as their approximate proportion in the products examined. 
Still more important are the results of tests for preservatives, dyes, for- 
eign gelatinous substances, and mineral acids used as coagulators. 

Preparation of the Sample. — In the case of jams, marmalades, and 
preserves, separate and weigh the stones, if present, then thoroughly pulp 
the sample. In the case of jellies rub the sample through a sieve. Stir 
well before weighing out the portions for analysis. 



99G FOOD INSPECTION AND ANALYSIS. 

Determination of Total Solids. — Weigh 4 to 5 grams of the sample 
into a large flat-bottomed dish (preferably of platinum) containing from 
4 to 5 grams of ignited asbestos and add enough water to uniformly 
distribute the material. Evaporate to dryness and dry for from twenty 
to twenty-four hours in a boiling water-oven. 

The results by this method are not strictly accurate owing to the 
dehydration of levulose, but for practical purposes they are sufhciently 
close. If extreme accuracy is required dry in vacuo at 70° or in a McGill 
oven (page 609). 

The solids in a jelly may also be calculated from the specific gravity. 

Determination of Ash. — Burn the residue from the determination of 
solids, or else a new portion, in a platinum dish at dull redness. 

Alkalinity of ash is determined as described for insoluble ash in maple 
products (page 657). 

Chlorides and Sulphates are detected in the ash by the usual tests. 
If the portion used for determination of alkalinity is also to be used for 
the chlorine test the titration must be made with fifth-normal nitric acid. 

The presence of chlorides is an indication of glucose, as pure fruit 
products do not contain appreciable amounts of chlorine compounds. 

Determination of Insoluble Solids. — Kremla Method* — Thoroughly 
macerate 50 grams of the sample in a mortar with warm water, then 
transfer to a filter and wash thoroughly with warm water, stirring well 
after each addition. Wash up to 500 cc, or in extreme cases up to 1000 cc, 
remove the insoluble solids to a dish, dry in a boiling water-oven, and 
weigh. Kremla employed a coarse filter paper for collecting the insoluble 
solids ; Munson and Tolman f found muslin more satisfactory. 

Reserve the filtrate for determinations of soluble constituents. 

German Official Method.^ — Transfer a weighed portion of the sample 
to a graduated flask, add water, shake thoroughly and make up to volume. 
Allow to settle and either filter or decant off the supernatant liquid. Deter- 
mine the soluble solids by evaporating and drying an aliquot. The insoluble 
solids are obtained by subtracting the soluble from the total solids. 

Determination of Acidity. — Dilute an aliquot of the solution from 
the insoluble solids of a jam or of a solution of a jelly and titrate with 
standard alkali. Use phenolphthalein as indicator if the color of the 



*Zeits. Nahr. Hyg. Waar., 6, 1892, p. 483. 

t U. S Dept. of Agric, Bur. of Chem., Bui. 65, 1902, p. 76; Bui. 66 rev., p. 13. 

t Vereinb. Unters. Beurt. Nahr. Genussm. deutsch. Reich., 2, p. 105. 



VEGETABLE AND FRUIT PRODUCTS. 997 

solution will permit, otherwise use litmus paper. Calculate the result 
as sulphuric acid or as the organic acid known to predominate (see page 
1008). 

Some of the methods for the determination of individual acids in fruit 
juices (pages 1008 and 1009) ^.re applicable to jams and jellies, but the 
analyst will do well to test their accuracy on mixtures of known composi- 
tion, especially if substances other than fruit and sugar are present. 

Determination of Protein. — Determine nitrogen in 5 grams of the 
material by the Kjeldahl or Gunning method and calculate protein, using 
the factor 6.25. 

Determination of Sugars. — In products of the highest grade, wherein 
only cane sugar is employed, a large portion of the cane sugar is inverted 
in the process of boiling the jam or jelly, so that when the analyst exam- 
ines it, he finds, as a rule, only a small amount of sucrose, and considerable 
invert sugar. The amount of cane sugar equivalent to the invert sugar 
may be calculated if this is thought desirable. It is further of interest to 
calculate, at least approximately, the percentage of commercial glucose, 
when present, especially in cases where the package contains a formula 
setting forth the amount of the various ingredients used. In such cases the 
analyst is naturally called upon to verify the formula, since a wide varia- 
tion in percentage composition from the statement on the label would 
constitute an offense under same state laws. 

Polarization. — Use half the normal weight of the preserve or jelly for 
the Schmidt and Haensch instrument, namely 13 grams in 100 cc. If 
fresh fruit or fruit juice is to be examined, use the full normal weight, 
26 grams. Clarify, before making up to the mark, with subacetate of 
lead and alumina cream (using 2 to 3 cc. of each clarifier), filter, and 
obtain the direct reading; then invert in the usual manner, and obtain 
the invert readings at 20° C, and in the water-jacketed tube at 87° C, 
proceeding in detail as directed under honey, page 671. 

Calculation of Sugars. — Sucrose is determined by using the Clerget- 
Herzfeld formula: 

„ (a — b) 100 



142.60 — 

2 



(I) 



This represents the sucrose actually present as such in the preserve 
or jelly, and not the amount originally used. If the latter (6"') is desired, 
it may be roughly calculated by the following formula: 



998 FOOD INSPECTION AND ANALYSIS. 

5' = -^22*_, (,) 

42.66 

2 

The results by this formula are too high, since part of the invert sugar 
was a natural constituent of the fruit. 

If, after inversion, the correct reading at 20° is found to be 12 or more 
to the left of the zero, it can be safely inferred that no appreciable amount 
of commercial glucose is present, and it is unnecessary to make a third 
reading at 87°, unless to confirm the fact. In such a case, v^ith cane sugar 
alone present, the reading at 87° will not, of course, vary much from zero. 

Invert Sugar. — In the absence of commercial glucose, the invert sugar 

is calculated as follows : 

T , (Sucrose— direct reading) iQi;.^ ,. 

Invert sugar = -^^ — — ^^-^, • • • (3) 

42.66—- 
2 

or it may be determined directly from the copper reducing power. 

Any decided reading above zero at 87° is due to the presence of com- 
mercial glucose, and when the latter is present, it is impossible to deter- 
mine the invert sugar from the copper reduction or by formula No. 3. 
The following formula is proposed for calculating approximately the 
invert sugar from the polarization, in the presence of commercial glucose. 
While theoretically correct, the method is subject to practical limitations, 
which admit of only roughly approximate results in such mixtures as jelly 
or jam. It is perfectly accurate only in mixtures of sucrose, glucose, and 
invert sugar. 

/Reading due to glucose and\ /Invert readingX 

, , \ inverted sucrose at /° / \ at /° / , , 

Invert sugar = ^ '-^ ^105.3 (4) 

±(42.66-- 

These formulas, (3) and (4), serve at best to indicate the approximate 
amount of invert sugar present in the sample, resulting from the inversion 
of a portion of the original sucrose in the natural process of manufacture 
of the jam or jelly, and not the total invert sugar resulting from the inver- 
sion by the analyst of all the sucrose. 

The factor 105.3 is used, since, in the natural process of inversion, 100 
parts of sucrose become 105.3 parts of invert sugar. 

Example. — The invert sugar in the sample of apple jelly first on the 
list in the table on page 995 is calculated as follows : 



VEGETABLE AND FRUIT PRODUCTS. 999 

Invert reading at /° (20°) = 28.0. 

Reading due to glucose at 20° =.221 X 175 = 38.68. 

Reading due to inverted sucrose at 20° = . 268 X —34= — 9.11. 

T , (38.68 -O.Il) -28 

Invert sugar =^^:^ — loc;.^ 

^ 28.66 ^ ^ 

-576%. 

Determination of Reducing Sugar. — Proceed as described on page 982. 

Commercial Glucose.— While it is impossible to determine the exact 
percentage of this substance in preserves and jellies, by reason of the 
varying composition of its component parts, it is quite feasible to approx- 
imate very closely to the amount present. Indeed, this approximate 
method of calculation, wherein glucose is treated as a chemical entity, 
has been found in practice to be much more close to the actual truth 
than results gained by methods wherein the copper-reducing power enters 
as a factor, or methods for determining separately dextrin, maltose, and 
dextrose. Calculate the commercial glucose in jellies and jams exactly 
as in the case of honey, page 673. 

Detection of Dextrin.* — Add alcohol to a somewhat thick solution of the 
fruit product. A white turbidity is at once apparent, followed by the for- 
mation of a thick gummy precipitate if dextrin is present. In the absence 
of dextrin there is no turbidity, but a light flocculent precipitate. 

Determination of Dextrin. — Bigelow and McElroy Method.] — Dissolve 
10 grams of the sample in a loo-cc. graduated flask, add 20 mg. of potas- 
sium fluoride, and then about one-quarter of a cake of compressed yeast. 
Allow the fermentation to proceed below 25° C. for two or three hours to 
prevent excessive foaming, and then place in an incubator at a temperature 
of from 27° to 30° C. for five days. At the end of that time clarify with 
lead subacetate and alumina cream; make up to 100 cc. and polarize in a 
200-mm. tube. A pure fruit jelly will show a rotation of not more than a 
few tenths of a degree either to the right or to the left. If a Schmidt and 
Haensch polariscope be used, and a 10% solution be polarized in a 
200-mm. tube, the number of degrees read on the sugar scale of the instru- 
ment, multiplied by 0.8755, will give the percentage of dextrin, or the fol- 
lowing formula may be used : 

C X 1000 X V 



Percentage of dextrin = 



198X^x1^' 



* U S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 78. 
t Jour. Amer. Chem. Soc, 15, 1893, p. 668. 



1000 FOOD INSPECTION AND ANALYSIS. 

in which 

C= degrees of circular rotation; 

F = volume in cubic centimeters of solution polarized; 

Z = length of tube in centimeters; 

W = weight of sample in solution in grams. 

Determination of Crude Pectin (Alcohol Precipitate). — Munson and 
Tolman Method.'^ — Evaporate loo cc. of a 20% solution of jelly, or 
200 cc. of the washings from the determination of insoluble solids of 
a jam, to 20 cc; add slowly and with constant stirring 200 cc. of 95% 
alcohol and allow the mixture to stand overnight. Filter and wash 
with 80% alcohol by volume. Wash this precipitate off the filter paper 
with hot water into a platinum dish; evaporate to dryness; dry at 100° C. 
for several hours and weigh; then burn off the organic matter and weigh 
the residue as -ash. The loss in weight upon ignition is called alcohol 
precipitate. 

The ash should be largely lime and not more than 5% of the total 
weight of the alcohol precipitate. If it is larger than this some of the 
salts of the organic acids have been brought down. Titrate the water- 
soluble portion of this ash with tenth-normal acid, as any potassium 
bitartrate precipitated by the alcohol can thus be estimated. 

The general appearance of the alcohol precipitate is one of the best 
indications as to the presence of glucose and dextrin. Upon the addition 
of alcohol to a pure fruit product a flocculent precipitate is formed with 
no turbidity while in the presence of glucose a white turbidity appears 
at once upon adding the alcohol, and a thick, gummy precipitate forms. 
Since the precipitate in the latter case consists in part of substances other 
than pectin bodies the results should be stated as representing " alcohol 
precipitate " and not " pectin." 

German Method.-f — This method, designed for juices, may also be used 
for jams and jellies. It differs from the Munson and Tolman method 
chiefly in that a smaller proportion of alcohol is used and a correction is^ 
introduced for protein. 

Detection of Coloring Matter. — Boil white woolen cloth or worsted 
in a solution of the jelly or jam, acidified with hydrochloric acid, or with 
acid sulphate of potassium, according to Arata's method and test for 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, 1902, p. 79; Bui. 66 rev., p. 21. 
t Koenig, Chemie d. mensch. Nahr. u. Genussm. Ill, 2, 1914, p. 891. 



VEGETABLE AND FRUIT PRODUCTS. 1001 

the^ color on the dyed fabric by methods given in detail in Chapter XVII. 
Apply also the general methods described in that chapter. 

Detection of Preservatives and Concentrated Sweeteners.— Extract an 
acid aqueous solution of the fruit product with ether or chloroform in 
a separatory funnel, and test for benzoic and salicylic acids and for sac- 
charin in the ether extract. If dulcin is suspected, extract with acetic 
ether. 

Detection of Starch.* — Heat an aqueous solution of the preserve 
or jelly nearly to the boiling point, and decolorize by the addition of several 
cubic centimeters of dilute sulphuric acid and afterwards permanganate 
cf potassium. This treatment does not aflFect the starch, which is tested 
for with iodine in the ordinary manner in the solution after cooling. In 
.he clear fihrate from a boiled apple pulp solution, free from added starch, 
li.tlc or no darkening should occur on the addicion of the iodine reagent. 
If, however, the reagent is added to the residue of the previously boiled 
pulp, the presence of starch inherent in the apple is usually recognized 
by the blue color produced thereon. 

The presence of any considerable added starch paste in a fruit prepa- 
ration is thus readily indicated by an intense blue color obtained by adding 
the iodine reagent to the filtrate (free from fruit pulp). 

Detection of Gelatin. — Robin's Method.'f — Add to a thick aqueous 
solution of the preserve or jelly sufficient strong alcohol to precipitate 
the gelatin. Decant the supernatant liquid after settling, set aside part 
of the precipitate, and dissolve the remainder in water. Divide the latter 
soluiion in two parts, to one of which add, drop by drop, a fresh solution 
of tannin, which precipitates gelatin if present. To the remainder add 
picric acid solution, which in presence of gelatin forms a yellow precip- 
itate. The portion of the yellow precipitate set aside is transferred to 
a test tube, and heated over the flame with a little quicklime. If gelatin 
is present, ammonia will be given off, apparent by the odor, and by fumes 
of ammonium chloride when a drop of hydrochloric acid on a glass rod 
is held at the mouth of the bottle. 

Lepnann and Beani's Method. X — Boil the sample with water, filter, 
and boil the filtrate with an excess of potassium bichromate. Cool, and 
add a few drops of sulphuric acid. A flocculent precipitate indicates 
gelatin. 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 65, p. 81. 
t Girard, Analyse des Matieres Aiimentaires, p. 676. 
X Select Methods of Food Analysis, p. 324. 



1002 FOOD INSPECTION AND ANALYSIS. 

Detection of Agar Agar.*— The jelly is heated with 5% sulphuric 
acid, a little potassium permanganate is added, and, after settling, the 
sediment is examined by the microscope for diatoms, which will be found 
in large numbers if agar agar has been used. 

Detection of Apple Pulp. — A distinct clue to the presence of apple 
pulp in fruit preparations is often furnished by the characteristic apple 
odor given off when a small amount of the sample is heated to boiling 
with water in a test tube. Under such conditions, the apple odor is quite 
apparent, as distinguished from that of other fruits, especially if the 
apple is the chief fruit present, or predominates in the mixture. 

Apple pulp in fruit preserves, free from added starch, may usually 
be recognized by a microscopical examination, using iodine reagent. 
The cell contents of the pulp will show the characteristic blue color, 
undoubtedly due to portions of unconverted starch still remaining in 
them. 

Detection of Fruit Tissues under the Microscope. Certaiii of the 
common fruits are readily identified in jams by their microscopic char- 
acters. This is especially true of most of the small fruits, the skins, 
styles and seeds being more or less characteristic in structure. 

The apple differs from the quince and pear in that stone cells are lack- 
ing; the starch of the green fruit is noteworthy. Peaches, plums and 
apricots, while possessing skins and stone peculiar to each, when pared 
and freed from stones are much alike in structure. Pineapples have 
peculiar needle-shaped crystals. Figs are identified by the " seeds " 
and hairs. Citrus fruits are remarkable because of the oil cavities and 
spongy parenchyma. Fragments of elements of the skins and cores of 
fruits, although pared and cored before preparation, find their way into 
the finished products, furnishing evidence to the microscopist. The seeds 
of berries are highly characteristic. 

DRIED FRUITS. 

Desiccation is the oldest and in some respects the most satisfactory 
method of preserving fruits. It is an economical method, as the apparatus 
and the process are simple, especially if the sun's heat is utilized for the 
evaporation; furthermore, the cost of the containers is small and the 
compact form of the product reduces the cost for transportation and storage 

* Marpniann, Zeit. f. angew. Mikrosk., 1896, p. 260; U. S. Dept. of Agric, Bur. of 
Chem., Bui. 65, p. 81. 



VEGETABLE AND FRUIT PRODUCTS. 1003 

to the minimum. From the sanitary standpoint dried fruit has certain 
advantages, notably the freedom from metallic impurities from the con- 
tainers; on the other hand, great care is required to protect the material 
during drying and handling from surface contamination. 

Xanti currants as well as raisins are dried grapes of certain European 
varieties. These, together with figs and dates, although produced in 
California and the Southern States, are imported into the United States 
in enormous quantities from the regions adjoining the Mediterranean. 
Apples, prunes, apricots, peaches, and cherries, on the other hand, are 
produced in the United States in quantities not only sufficient for domestic 
needs but also for export. 

California fruits, such as raisins, prunes, apricots, peaches, and pears 
are sun-dried, as are also raisins, figs, dates and other fruits produced 
about the Mediterranean. Apples are commonly dried in the United 
States by artificial heat, although the old process of sun drying is still 
practiced on a small scale in certain regions. 

Treatment with Lye.— Preliminary to drying certain fruits, such as 
raisins and prunes, are often dipped in a hot but weak solution of potash, 
which removes the bloom and otherwise acts on the skin, thus faciHtating 
drymg. Oil is also used with the lye in preparing " oil-dipped " Smyrna 
raisins. These methods of treatment are quite distinct from the lye- 
peeling process employed in preparing peaches, apricots, and some other 
fruits for canning. 

Sulphuring of Fruit.— The treatment of fruits with the fumes of burning 
sulphur is practiced not only to bleach and prevent discoloration, but also 
to ward off the attacks of insects, fungi, and bacteria. It is allowed with 
restrictions in most European countries and also, pending further inves- 
tigation, in the United States, provided the amount of sulphur dioxide 
remaining in the fruit does not exceed 350 mg. per kilo, of which not more 
than 70 mg. is free sulphurous acid.* 

There is reason to believe that the sulphur dioxide exists in dried 
fruits in combination largely, if not wholly, with sugar, although possibly 
to some extent, as in wines, with acetaldehyde, or even with protein and 
cellulose. 

Sulphuring when used for purposes of deception, as for example in 
rejuvenating old or damaged stock or when used in excessive amount, is 
obviously improper. Analyses by government chemists show that when 

* U. S. Dept. of Agric, Off. of Sec, Food Inspection Decision 76. 



1004 FOOD INSPECTION AND ANALYSIS. 

no restrictions were placed on sulphuring as high as 3072 mg. per kilo 
were present in dried peaches, 2842 mg. in California apricots and 1738 mg. 
in evaporated apples. 

Moisture Content of Dried Fruits. — An excessive amount of moisture 
in dried fruit is not only a worthless make-weight, but also facilitates the 
growth of molds and bacteria, causing rapid deterioration. In 1904 a law 
was passed in New York State requiring that dried apples contain not 
above 27% of moisture, determined by drying four hours at the temperature 
of boiling water. 

Wormy and Decomposed Dried Fruits. — Figs, dates, and currants 
from Europe, also dried apples, cherries, and other fruits of domestic 
production often are infected with worms or are in a moldy or fermented 
condition due to careless drying or packing. Under the federal law such 
" filthy, decomposed or putrid " fruit is adulterated. 

Zinc in Dried Fruit. — Apples dried in contact with galvanized iron 
trays may contain o.oi to 0,02%, or in extreme cases, according to 
Loock, 0.09% of zinc as malate. This contamination may be avoided 
by greasing the trays, covering them with greased cloths, or using wooden 
trays. 

FRUIT JUICES. 

Such preparations, if of the highest purity, should consist of the un- 
diluted juices of these fruits, separated by pressure and carefully ster- 
ilized and bottled. They should contain no other fruit juice than that 
specified on their labels, and should be free from alcohol, added antisep- 
tics, or coloring matter, unless the label specifies the presence of the added 
foreign materials. The addition of pure cane sugar to such prepara- 
tions as grape juice is allowable if declared, as well as charging with carbon 
dioxide to form so-called carbonated drinks. 

Composition of Fruit Juices. — Analyses of various fruit juices, 
pressed out in the laboratory, by Munson and Tolman are given on 
page 992. 

The following analyses of pure fruit juices are taken from tables pre- 
pared by Winton, Ogden, and Mitchell, showing results on samples pur- 
chased in the Connecticut market, as well as on some samples made in 
the laboratory:* 

* Conn. Agric. Exp. Sta. Rep., 1899, p. 136. 



VEGETABLE AND FRUIT PRODUCTS. 



1005 



COMMERCIAL FRITIT 
JUICES. 

Blackberry 

Cherry 

Black currant 

Red currant 

Grape 

Lime fruit 

Orange 

Pineapple 

Plum 

Quince 

Black raspberry 

Strawberry 

MADE I N LABORA- 
TORY. 

Peach 

Red raspberry 

Blackberry 

Huckleberry 

Pineapple 



Solids. 



12.70 
9.41 

8-94 
11.40 
13.90 



Acids 

Other 

than 

CO 2 as 

Citric. 



0.65 
0.80 
2.41 
2.og 
0.91 
6.50 

2-44 
0.81 
1 .00 
0.99 
1.36 
0.99 



0-95 
1. 19 



0-51 
0.68 



Cane 

Sugar. 



0.0 
0.0 
0.0 
0.0 
0.0 
0.0 
0.0 

1-5 
0.0 
0.0 
0.0 
0.0 



5-4 
0.8 
0.0 
0.6 
7-4 



Invert 
Sugar. 



4.6 

6.5 
9.2 

7-2 

0.0 
7-1 
5-1 
0-3 

7.i 
5-1 



2. 1 

8.6 



9.1 



Polarization. 



Direct. 



-1-3 
-1-9 
-2-7 
-2.1 

-6.5 
0.0 
-2.1 
0.0 
-o. I 
■5-0 
•2-3 
■1-5 



4-8 
-1.6 
■2.4 
■4.0 

4-7 



After 
Inver- 



•1-3 
■1-9 
■2.7 
-2.1 

■6.5 
0.0 



-5-0 



-2.4 
■4.8 
-4.8 



Temper- 
ature 
C. 



29.0 
26.0 
26.0 
27.0 
25.0 

26.0 
26.0 
26.0 
25.0 
26.0 
26.0 



28.0 
26.0 
30.0 
30.0 
28.0 



Invert 
Reading 
at S6° C. 



-0.8 



Grape Juice. — Following are the averages of analyses of grape juice 
made from European varieties of grapes reported by Bioletti and dal Piaz :* 





Alcohol. 


Solids 
Calc. 
from 
Specific 
Grav- 
ity. 


Sugar. 


Acidity 
Calc. 

as 
Tar- 
taric. 


Vola- 
tile 
Acid. 


Free 
Tar- 
taric 
Acid. 


Cream 

of 
Tartar. 


Ash. 


Phos- 
phoric 
Acid. 


Made in — 

Austria 

California 


none 
none 


21.62 
20.60 


19.62 
19- IS 


0.78 
0.53 


O.OI 
0.03 


0.03 
0.07 


0.61 
OS9 


0.37 
0.19 


0.02 
0.04 



The table given below, summarized from tables by Hartmann and 
Tolman,t shows the maximum, minimum, and average of analyses of 
93 samples of commercial grape juice obtained under supervision at five 
factories in New York state and one in Ohio during the years 1912, 1913, 
and 1914. 



* Cal. Agr. Exp. Sta., Bui. 130, 1900. 
t U. S. Dept. of Agric, Bui. 656, 1918. 



1006 



1 



FOOD INSPECTION AND ANALYSIS. 





Alcohol 

Vol. 

per 
Cent.* 


Grams per loo cc. 


Cc. N/io Acid 
per 100 cc. 




Solids.t 


Sugars 

Calc. 

as 

Invert t 


Acidity 
Calc. 

as 
Tar- 
taric. § 


Free 
and 
Com- 
bined 
Tartaric 
Acid. II 


Free 
Tar- 
taric 
Acid.t 


Cream 
of 
Tar- 
tar. 


Ash. 


Tannin 

and 
Color- 
ing 
Mat- 
ter.** 


Alka- 
linity 
Water- 
soluble 
Ash. 


Alka- 
linity 
Water- 
in- 
soluble 
Ash. 


Max 

Min 

Aver 


0-37 
0.02 
O.I2 


20.78 
14.20 
18.33 


17-53 
11.52 

15-31 


1.28 
0.81 
1. 01 


1. 01 
0.56 
0.74 


0.36 
0. 12 
0.23 


0.79 
0.36 
0.54 


0.37 
0.22 
0.29 


0.37 
0.07 
0.24 


42.0 
19.0 
28.7 


8.8 
3-1 
S-i 



♦By immersion refractometer. 

t Brix. 

t Direct and invert polarization practically the same. 

I Spotted into litmus solution. 

II Total tartaric acid by Hartmann and Eoff. method (p. 731). 
If Calc. from total tartaric acid and cream of tartar (p. 732). 
** Lowenthal method. 



Sweet Cider. — The composition of pure, freshly expressed apple juice 
is shown by the following table of analyses by Browne : * 























Left- 














Total 






Unde- 


handed 




Specific 




Invent 


Su- 


Total 


Sugar 


Free 




ter- 


Rotation 




Gravity. 


Solids. 


Sugar. 


crose. 


Sugar. 


after 

Inver- 
sion. 


Mahc 

Acid. 


Ash. 


mined 

(Pectin, 

etc.;. 


Degrees 

Ventzke 

400 mm. 

Tube. 


Redastrachan 


1-0532 


12.78 


6.87 


.S-63 


10.50 


10.69 


1. 14 


0.37 


0.77 


23.72 


Early harvest 


1-0552 


13.29 


7-49 


3-97 


11.46 


11.67 


0.90 


0.28 


0.65 


24.32 


Yellow transparent. 


1.0502 


II. 71 


8.03 


2.10 


10.14 


10.24 


0.86 


0.27 


0.44 




Sweet bough 

Baldwin, green. . . . 


1.0498 
1.0488 


11.87 
11.36 


7.61 
6.96 


3.08 
1.63 


10.69 
8.59 


10.8s 
8.68 


0. 10 






39-40 
36.16 


1.24 


0.31 


1.22 


' ' ripe. .... 


1.0736 


16.82 


7-97 


7-05 


15.02 


15-39 


0.67 


0.26 


0.87 




Ben Davis 


1-0539 


12.77 


7. II 


3-85 


10.96 


11.16 


0.46 


0.28 


1.07 


49.00 



Determination of sugars in the juice of 15 American and 5 French 
varieties of apples made by Eoff t showed that in every instance the amount 
of levulose exceeded that of dextrose and sucrose combined. 

Bottled sweet cider, properly sterilized, should not differ materially 
from the fresh juice, and should contain no considerable amount of alcohol. 

Salicylic acid, sodium benzoate and sodium or calcium bisulphite 
have been extensively used as preservatives, Benzoate is still used to some 
extent. 

Lime or Lemon Juice. — The juice of both the lime and the lemon is 
known commercially as lime juice and the Canadian standard goes so far 

* Penn. Dept. Agric, Bid. 58, p. 29. 
t Jour. Ind. Eng. Chem., 9, 1917, p. 587 



VEGETABLE AND FRUIT PRODUCTS. 



1007 



as to recognize "various species" of Citrus. In former editions of the 
U. S. Pharmacopoeia C. limonum was specified and the product known as 
lemon juice was required to conform to the following: Specific gravity 
at 15° C. at least 1.030, citric acid about 7^1, and ash not more than 0.5%. 
In the 9th decimal revision neither lemon nor lime juice is given. 

The table below shows the range in composition of 40 samples classed 
by McGill * as genuine, together with the Canadian limits fixed by Order of 
Council, Jan. 28, 191 5. Many of the samples werq preserved with benzoic, 
salicylic, or sulphurous acid. 

COMPOSITION OF LIME JUICE (McGill) 





specific 

Gravity, 

20° C. 


Total 
Solids. 


Acidity Calc. 
as Citric. 


Rotation in 

200-mm. 
Tube, ° v. 


Genuine lime juice: 

Maximum 

Minimum 

Canadian limits: 

Maximum 

Minimum 


I 0531 
1.0305 

1 .040 
1.030 


12.12 

7.76 
8.00 


10.18 
6-93 

7.00 


+0.6 

— 2.2 

+0.5 

— I.O 



Samples examined in previous years at the laboratory of Inland Revenue, 
Canada, and at the Mass. State Board of Health were often found to be 
watered, preserved with salicylic, benzoic, or sulphurous acid, artificially 
colored, or otherwise sophisticated. One sample, examined by Leach 
purporting to be " pure West Indian lime juice, triple refined," proved to 
be a mixture of hydrochloric and salicylic acids, colored with a coal-tar 
dye, and containing no lime juice whatever. 



METHODS OF ANALYSIS. 

Total Solids, Total Nitrogen, Ash, and Sugars are determined by the 
methods employed for jams and jellies (pp. 995 to 1002), Solubility and 
Alkalinity of the Ash and Phosphoric Acid as described in the chapter 
on vinegar (p. 795). 

Colors and Preservatives are detected and determined as described 
in Chapters XVII and XVIII. 

Total Acidity. — Titrate 10 grams of the juice, diluted to 250 cc. with 
freshly boiled water, with tenth-normal alkali. Use phenolphthalein as 

* Lab. Inl. Rev. Dept., Bui. 321, 1916. 



1008 FOOD INSPECTION AND ANALYSIS. 

indicator if the color of the juice will permit, otherwise delicate litmus paper. 
Calculate either as sulphuric acid or as the organic acid known to pre- 
dominate. 

One cc. of tenth-normal alkali is equivalent to 0.0075 gram tartaric 
acid, 0.0067 gram malic acid and 0.0064 gram citric acid. 

Determination of Total Tartaric Acid. — Proceed as directed for wine, 
p. 731, using only 50 cc. of the sample diluted to 100 cc. and adding 20 
instead of 15 cc. of alcohol. 

Determination of Malic Acid. — Dunbar and Bacon Method.^ — Dilute 
a weighed or measured amount of the fruit juice, usually 10 grams, with 
fjuite a large volume of water, add phenolphthalein, and titrate with 
standard alkali to a decided pink color. Weigh or measure another 
portion of the liquid (75 grams or cc. is a convenient amount) into a loo-cc. 
graduated flask, and add enough standard alkali, calculated from the 
above titration, to neutralize the acidity. A slight excess of alkali is not 
objectionable. If the solution is dark colored, add 5 or 10 cc. of alumina 
cream. Dilute to the mark, mix thoroughly, and filter if necessary through 
a folded filter. 

Treat about 25 cc. of the filtrate with enough powdered uranyl acetate 
so that a small amount remains undissolved after two hours, 2.5 grams 
usually being sufficient, except in the presence of large amounts of malic 
acid. In case all the uranium salt dissolves more should be added. Allow 
to stand for two hours, shaking frequently, filter through a folded filter 
until clear and polarize if possible in a 200-mm. tube or, if too dark, in 
a 100- or 50-mm. tube. Designate this solution and reading as A. 

Treat the remainder of the original filtrate with powdered normal 
lead acetate until the precipitation is just complete, avoiding a large excess 
and consequent solution of lead malate. Cool in an ice bath and filter 
through a folded filter until clear. Warm the filtrate to room temperature 
and add a small crystal of lead acetate. If no precipitate forms, remove 
the excess of lead with anhydrous sodium sulphate, filter until clear, and 
polarize. Designate this solution and its polarization reading as B. 
Solutions which are sufficiently clear and contain less than 10% of sugar 
may be polarized directly without treatment with lead acetate. 

If reading B is negative treat a portion of solution B with uranyl acetate 
in the manner already described and polarize. Designate this as C. 
If reading B is positive, reading C need not be made. 

* U. S. Dept. of Agric, Bur. of Chem.. C'\rr , 76. Jour. Ind. Eng. Chem., 3, 1911, p. 826. 



VEGETABLE AND FRUITS PRODUCT. 1009 

Polarize all solutions at a uniform room temperature with white light, 
using the average of at least six readings and calculating to the basis of a 
200-mm, tube. If reading C is numerically less than reading B, the latter 
should be discarded; otherwise use reading B in the subsequent calcula- 
tion. Multiply the algebraic difference between this reading and reading 
A by 0.036, the product being the percentage of malic acid (C4H6O5) 
in the solution as polarized. 

PraWs Modification.'^ — Place a weighed amount of juice, generally 
100 grams, in a 500-cc. beaker and add, with vigorous stirring, two or 
three times its volume of 95% alcohol. The pectin bodies are precipitated 
and usually in such a form that after standing a few minutes they may be 
gathered into a coherent mass. Decant the liquid through a filter and wash 
the precipitate twice with 95% alcohol. Evaporate the filtrate in a cur- 
rent of air on the water-bath to about 75 cc. After cooling make up to 
100 cc. in a measured flask, using 10 to 15 cc. of 95% alcohol and dis- 
tilled water. The temperature when the volume is finally made up to 
the mark should be close to that at which the polariscope readings are to 
be taken. Treat this solution exactly as in the original method, except 
that no clarification is necessary. 

Determination of Citric Acid. — Pratt Method. "f — This method is 
applicable in the presence of malic and tartaric acids, but according to Bige- 
low and Dunbar { does not give accurate quantitative results although 
it serves to show the presence or absence of citric acid. Willaman's modi- 
fication § is designed to correct the defects of the method but has not yet 
been rigidly tested. Dunbar and Lepper 1 1 recomimend the Stahre-Kunz 
method. The original Pratt method is here given pending further improve- 
ment or the introduction of a better method. 

'i. Apparatus. — This consists of a 500-cc. distilling flask provided 
with a small dropping funnel drawn down to a small opening and pro- 
truding h inch below the stopper. In the flask is placed a glass rod with 
a piece of small tubing >> Inch long, sealed on the lower end to insure steady 
ebullition. This small tube should be filled with air when the heating 
begins. A condenser preferably of the spiral type is connected with the 
flask. 



* U. S. Dept. of Agric, Bur. of Chem., Circ. 87. 

f U. S. Dept. of Agric, Bur. of Chem., Circ. 88, 1912. 

f Jour. Ind. Eng. Ciiem., 9, 1917, p. 762. 

§ Jour. Amer. Chem. Soc, 38, 1916, p. 193. 

II Jour, .^ssn. Off. Agr. Chem., 2, II, 1917, p. 175. 



1010 FOOD INSPECTION AND ANALYSIS. 

2. Denigh Reagent. — Add about 500 cc. of water to 50 grams of mercuric 
oxide; then add 200 cc. of concentrated sulphuric acid with constant 
stirring, and heat the mixture, if necessary, on a steam bath until the 
solution is complete. After cooling make up to a liter and filter. 

3. Determination. — Weigh 50 grams of the fruit juice into a beaker 
and add no cc. of 95% alcohol to throw out the pectin bodies. After 
standing fifteen minutes filter and wash with 95% alcohol. Dilute the 
filtrate with water to approximately 50% alcohol content and add enough 
20% barium acetate solution to precipitate the citric acid. Stir, let stand 
until the barium citrate partially settles, and filter. Wash twice with 
50% alcohol to remove the greater part of the sugar present. Remove 
all alcohol from the precipitate and filter either by drying in the beaker 
used for precipitation or else by washing with ether before removing from 
the funnel. Add 50 cc. of water and 3 to 5 cc. of sirupy phosphoric acid 
to the beaker containing the filter-paper and precipitate and warm, thus 
dissolving the barium citrate completely. Filter into a 100 cc. measuring 
flask and wash up to the mark. 

Measure an aliquot containing from 0.05 to 0.15 gram of citric acid, 
into the distilling flask, add 5 to 10 cc, of sirupy phosphoric acid and 
400 cc. of hot water. Connect with the condenser, heat and when briskly 
boiling, add potassium permanganate solution (0.5 gram per liter), i to 2 
drops per second, until a pink color persists throughout the solution. 
Distil off the acetone formed by the oxidation into a liter Erlenmeyer 
flask containing 30 to 40 cc. of Deniges reagent, continuing the distilla- 
tion until so to ICO- cc. remain in the flask. Boil the distillate gently 
under a reflux condenser for forty-five minutes after it turns milky. 
Filter hot through a Gooch crucible, wash the precipitate with water, 
alcohol, and finally with ether, and dry in a water-oven for half an hour. 
The weight of the precipitate multiplied by 0.22 gives the weight of citric 
acid. 

FRUIT SYRUPS. 

Two classes of these preparations are on the market, one for use in 
soda-fountains, and one for " family trade," intended as a basis for sweet- 
ened drinks to be diluted with water and sugar. Some are made exclu- 
sively from fruit pulp or juice and sugar, sterilized by heating and put-up 
in tightly sealed bottles, while others of the cheaper variety are more 
apt to be entirely artificial both in color and in flavor, deriving the latter 
principally from the wide variety of artificial fruit essences now available. 



VEGETABLE AND FRUIT PRODUCTS. 1011 

Commercial glucose is a frequent ingredient. The same classes of coal- 
tar dyes and antiseptics are found in these preparations as in the other 
fruit products. Citric or tartaric acid is frequently added to genuine 
fruit syrups to bring out the flavor and to imitation fruit syrups to better 
simulate the characters of the genuine product. 

For purposes of comparison with such fruit-pulp preparations as 
may come to the analyst for examination, he is referred to the analysis 
of fruits found on pages 283 and 993. 

NON-ALCOHOLIC CARBONATED BEVERAGES. 

Soda Water. — Originally the beverage known as soda water was 
prepared by the action of an acid on sodium bicarbonate in solution and 
corresponded to what is now obtained by dissolving Seidlitz powders 
in water. Later it was found that water charged with carbon dioxide 
is not only more practicable commercially but also more acceptable 
to the palate, and this product was substituted for true soda water without 
change of name. 

As dispensed by the pharmacist and confectioner in the United States, 
soda water consists of a syrup, variously flavored, mixed at the " fountain " 
with carbonated water. The syrup is first placed in the glass, then the 
carbonated water is drawn into it in a large stream and finally more added 
in a fine stream to mix and froth the liquid. Ice cream or liquid " cream " 
is used with certain flavors, eggs and milk in " egg chocolate," " egg shake " 
and other nutritious mixtures, a solution of calcium acid phosphate in 
" orange phosphate " and other phosphates — in fact there appears to be 
no end to the preparations and combinations introduced by ingenious 
vendors to quench the thirst, gratify the palate, and furnish nourishment 
in an easily digestible form. 

Carbonated Water, the basis of all effervescent drinks, is prepared by 
charging ordinary water with carbon dioxide in a steel drum, known as 
the fountain. Formerly the gas was generated on the premises by the 
action of mineral acid on marble, but now it is obtained in liquid form in 
steel cylinders from mineral springs and the fermentation industries where 
it formerly went to waste. 

The process of carbonating consists in allowing the gas to discharge 
into the water, rocking the fountain continually to aid absorption. A 
gauge indicates the pressure in the fountain, which should be about 170 
pounds per square inch for soda water and somewhat less for ginger ale 



1012 FOOD INSPECTION AND ANALYSIS. 

and root beer. The steel drum or fountain proper is kept in the cellar 
or other convenient place and the carbonated water is piped to the so-called 
fountain where the drinks are served, or, in the case of bottled beverages, 
to the machine for filling the bottles. 

Needless to say both the water and the gas should be free from con- 
tamination, and the introduction of metallic salts from the lead pipes and 
other sources should be guarded against. 

Soda Water Syrups. — Sugar and flavors are added to carbonated 
beverages in the form of syrups. At the soda fountain these are drawn 
into the glass from small reservoirs or poured from bottles, while in the 
bottling works measured quantities both of syrup and carbonated water 
are introduced into each bottle by an automatic machine. 

Fruit Syrups are prepared either by the manufacturer of soda water 
supplies or else by the pharmacist or confectioner who serves the beverages. 
More commonly the manufacturer supplies the fruit juice or fruit pulp 
in bottles or jars, spoilage being avoided either by sterilization or the use 
of sodium benzoate. The vendor mixes the juice or pulp with sugar 
syrup as needed. Orange, lemon, and lime syrups are commonly made 
from the oils rather than from the fresh fruit, the necessary acidity being 
supplied by citric acid. This acid as well as tartaric acid is also used in 
strawberry, raspberry and other true fruit syrups to bring out the flavor. 

Imitation Fruit Syrups flavored with mixtures of ethers such as are 
described on pages 954 to 956, are frequently substituted for genuine fruit 
syrups at soda fountains and quite universally in the preparation of cheap 
bottled soda water. Aside from the deception to the consumer these mix- 
tures are highly objectionable because of their nauseating and unwhole- 
some properties. 

Various Syrups not belonging under the head of fruit syrups are drawn 
from fountains and used in bottled beverages. Among these are vanilla, 
coffee, chocolate (really cocoa), ginger, sarsaparilla, and mixtures sold 
under distincti\'e names. 

Bottled Carbonated Beverages. — To this class belong various non- 
alcoholic beverages known as " soda," " soft-drinks " and " temperance 
drinks." Some of these are high-grade articles of national or even inter- 
national reputation, so prepared as to keep indefinitely, while others are 
cheap preparations of local manufacture sold for immediate consumption 
in pleasure resorts. 

Ginger Ale, by far the best-known bottled carbonated beverage, is made 



VEGETABLE AND FRUIT PRODUCTS. 1013 

from ginger (or ginger extract) with the addition of lemon juice (or lemon 
oil and citric acid) and carbonated water. Capsicum extract, known in 
solid form as capsicin, is frequently substituted in part for the ginger 
because of its greater pungency. 

Root Beer was formerly brewed from a sweetened infusion of various 
roots and herbs, the gas being formed by a true fermentation process. 
A similar beverage is now made in the household, using so-called " root- 
beer extract," but the commercial product is commonly charged, like soda 
water, with carbon dioxide gas. 

Birch Beer, formerly made by fermentation, is now merely soda water 
flavored with oil of birch or synthetic methyl salicylate. 

Sarsaparilla, so called, is flavored with a mixture of oil of birch, natural 
or synthetic, and oil of sassafras. The dark color is due to caramel or 
other artificial colors. 

Lemon Soda and Orange Soda are flavored respectively with terpene- 
less lemon and orange extract, the acidity being contributed by citric acid. 
Orangeade belongs in the same class. So-called blood orange soda is 
probably never made from blood oranges, the color being artificial. 

Vanilla Soda is more correctly vanillin soda or vanillin and coumarin 
soda. The term cream soda applied to this colorless beverage is equally 
misleading. 

Strawberry Soda, Raspberry Soda and other bottled beverages purport- 
ing to be made from fruits are commonly imitations flavored with ethers 
and colored with coal-tar dyes. So-called Cherry Soda is flavored with 
an extract of cherry bark or benzaldehyde. 

Sweeteners in Beverages. — Sugar is the only proper sweetener for 
syrups of botded beverages. Glucose because of its lower sweetening 
power is unsuited for the purpose, while saccharin and other chemical 
sweeteners are objectionable both because of their lack of nutritive prop- 
erties and their possible injury to health. The use of saccharin, which 
has hitherto been extensive, is now prohibited in beverages entering into 
interstate commerce. 

Acids in Beverages. — Citric and tartaric acids are used not only in 
imitation, but also in true fruit syrups to bring out the flavor. Lemon 
juice serves the same purpose, but is more expensive and does not keep so 
well. Calcium acid phosphate is a characteristic constituent of orange 
and other fruit phosphates. 

Preservatives.— Sodium benzoate is the common preservative of bev- 



1014 FOOD INSPECTION AND ANALYSIS. 

erages, although its use is by no means universal. Formerly salicylic, 
boric and sulphurous acids and even fluorides were employed. A recent 
German patent names /^-chlorobenzoic acid as a harmless preservative 
many times as effectual as benzoic acid. 

Artificial Colors.— Cochineal, cudbear, caramel and the eight colors 
allov^ed by U. S. decisions are most commonly met with. The use of 
fuchsin, acid fuchsin, rhodamine, and other coal-tar colors has been 
largely discontinued. 

Foam Producers. — Froth on soda water is cheaper to produce than the 
same bulk of liquid, furthermore it is sanctioned by custom. 

Soap-bark, the bark of Quillaja Saponaria, a common foam producer, 
contains two saponins, sapontoxin and quilliac acid, both of which are 
poisonous. In addition these principles combine with the cholesterin of 
the blood and if in excess dissolve the corpuscles. 

Commercial saponin, prepared from Saponaria officinalis, and consist- 
ing largely of sapotoxin, is also extensively used. 

Foam producers are also used in malt liquors. 

Glycerrhizin, the characteristic principle of licorice, also serves as a 
foam producer. 

Habit-forming Drugs in Beverages. — Caffein, extract of cola leaves, 
and cocaine are ingredients of certain proprietary syrups and beverages, 
contributing their well-known stimulating properties. The use of caffein 
is defended on the ground that it is the active principle of tea and coffee. 
Opponents of this drug have pointed out that tea and coffee are recognized 
as improper articles of diet for children and invalids, furthermore, the 
presence of other constituents tends to prevent the excessive use of these 
beverages. Again the presence of caffein in carbonated beverages is not 
usually known to the consumer, and he forms the habit without proper 
warning. 

It would be difficult to find an argument in favor of the use of a drug 
so potent as cocaine or products containing cocaine. 

METHODS OF ANALYSIS. 

Transfer the sample to a flask and shake at intervals for an hour or 
two, at room temperature, thus removing most of the carbon dioxide. 
Use. the liquid thus obtained for the several determinations, measuring 
out the portions, if desired, and calculating the weight from the specific 
gravity. 



VEGETABLE AND FRUIT PRODUCTS. 1015 

Total Solids, Ash, Acidity, and Individual Sugars are determined 
as directed for jams and jellies (pages 995 to 999) using 25 grams of the 
liquid except for the polarizations, which may be made on normal quantities. 

Vanillin, Coumarin, Citral, and Methyl Salicylate are detected and 
determined by the methods described under the head of Flavoring Extracts, 
with such modifications as are necessitated by the absence of alcohol on 
the one hand and the greater dilution on the other. Methods for the 
detection of Ginger and Capsicum are given on page 952. 

Detection of Colors, Preservatives, and Sweeteners.— See Chapters 
XVII, XVIII, and XIX. 

Determination of Phosphoric Acid.— This determination is made 
in so-called " orange phosphate," " raspberry phosphate " and other 
beverages containing calcium acid phosphate. 

Treat 25 grams of the liquid according to the method described on 
page 362, except that the entire residue, after ignition with magnesium 
nitrate, is used for the determination, without aliquoting. 

Determination of Alcohol — Follow the method prescribed for wines 
(page 687) . The amount of volatile oil present is seldom sufficient to appre- 
ciably affect the results. 

Detection of Saponin.— Of the various color tests that have been 
proposed none has been found absolutely characteristic, especially if 
glycerrhizin is present, although the reactions with sulphuric acid and 
Frohde reagent are of considerable value. The haemolysis test is believed 
to be reliable even in the presence of glycerrhizin. Whichever test is 
applied the saponin should be separated from interfering substances as 
follows : 

I. Extraction of Saponin by the Riihle-Briimmer Method.^ — In the 
case of soda water and other products containing organic or mineral 
acids (other than carbonic), to 100 cc. of the liquid add an excess of pre- 
cipitated magnesium carbonate and filter. If dextrin is present, as in 
the case of malt liquors, evaporate 100 cc. of the liquid to 20 cc, pre- 
cipitate with 150 cc. of 95% alcohol, let stand thirty minutes, then heat to 
boiling, filter, dilute the filtrate with water and dealcoholize, finally making 
up the solution to 100 cc. 

To 100 cc. of the neutral, dextrin-free solution in a separatory funnel, 
add 20 grams of ammonium sulphate, 9 cc. of phenol and shake thoroughly. 
Draw off the watery layer and shake the phenol solution with a mixture 

* Zeits. Unters. Nahr. Genussm., 5, 1902, p. 1197; 16, 1908, p. 165; 23, 1912, p. 566. 



1016 FOOD INSPECTION AND ANALYSIS. 

of 50 cc. of water, 100 cc. of ether, and (if necessary to avoid an emulsion) 
4 cc. of alcohol. Allow to stand until the liquids separate, which usually 
requires twelve to twenty-four hours. Draw off the aqueous solution and 
evaporate nearly to dryness, finishing the drying either at 100° C. or in a 
desiccator, the latter being preferable if the residue is to be purified by 
treatment with acetone, which is usually desirable. Employ this extract, 
consisting of saponin and impurities, in the following tests : 

II, Tests for Saponin. — i. Sulphuric Acid Test. — Rub up a portion 
of the extract with a few drops of sulphuric acid. Saponin is indicated 
by the appearance in a few minutes of a reddish color changing in half 
an hour to red- violet and finally to gray. 

2. Frohde Test. — Treat another portion in like manner with a few 
drops of a mixture of 100 cc. of concentrated sulphuric acid and i gram 
of ammonium molybdate. In the presence of saponin the drops in fifteen 
minutes become violet, changing later to green and finally to gray. 

3. Foam Test. — Shake another portion of the extract with water and 
note its foam-producing properties. 

In the presence of glycerrhizin none of the last three tests is reliable. 

4. Haemolysis Test. — This process is recommended by Rusconi,* 
Sormali,t and Rhiile.J The following details are given by Rhiile and are 
based on the method as described by Gadamer: § 

(a) Reagents. — (i) Physiological Salt Solution. — Dissolve 8 grams of 
sodium chloride in water and make up to one liter. 

(2) One per cent Defibrinated Blood. — Shake vigorously fresh ox 
blood in a sterilized, salt-mouth, 500-cc. bottle with 20 glass beads 5-7 mm. 
in diameter. Separate from the clot of fibrin and store in a sterilized 
container in a refrigerator. Properly cared for it should keep for several 
days. 

Dilute with 100 volumes of physiological salt solution for use. 

(3) One per cent Blood Corpuscles.— Centrifuge 100 cc. of the 1% 
defibrinated blood in physiological salt solution, pour off the clear solu- 
tion containing the cholesterol and make up again to 100 cc. with the salt 
solution. This preparation is more sensitive than solution (2). 

{b) Process. — Dissolve about o.i gram of the extract in 25 cc, of 
physiological salt solution, filter, and shake i, 2, and 3 cc. of this solution 

* Bol. Soc. Med. Chi., Pavia, 1910. 

t Zeits. Unters. Nahr. Genussm., 23, 1912, p. 562. 

i Ibid., p. 566. 

§ Lehrbuch der chemischen Toxicologic. Gottingen, 1909, p. 443. 



VEGETABLE AND FRUIT PRODUCTS. 1017 

in small test-tubes with i cc. portions of i% defribinated blood. If saponin 
is present the liquid becomes clear in from a miunte to an hour or two, 
depending on the amount of saponin in the beverage and the number of 
cubic centimeters of the solution used. 

As a confirmatory test dissolve i mg. of cholesterol in a small amount 
of ether, shake with lo cc. of the solution of the extract in salt solution, 
heat at 36° C, for a few hours to remove ether, avoiding concentration, 
and treat portions of this solution with 1% defibrinated- blood as above 
described. Cholesterol destroys the hasmolytic action of the saponin, 
hence the liquids should not become clear in these tests. In order to 
exert this influence cholesterol should be present to the extent of i part 
to 5 parts of saponin. 

If only a small amount of saponin is present the heemolytic action can 
best be noted under a microscope magnifying to 300 diameters. Mount 
a drop of the solution of the extract in salt solution and place a drop of 
either solution (2) or (3) in contact with it. The saponin causes the 
corpuscles in contact with it to swell, then become strongly refractive, 
and finally dissolve. 

Muller-Hossly * neutralizes 500 to 1000 cc. of the sample and blows 
a current of air into it through a glass tube extending to the bottom of the 
container, collects the foam which froths over, and makes the test on the 
liquid obtained by the subsiding of the foam. The saponin in the foam 
is in much greater amount than in the original liquid. 

Determination of Cd£Lem.~Fuller ikfe/AoJ.f— Weigh 50 grams or 
measure an equivalent volume into a small beaker, add 5 cc. of concentrated 
ammonium hydroxide, allow to digest overnight; then add 2 cc. more 
of ammonium hydroxide, heat for two hours, transfer to a large separatory 
funnel, dilute with 3 volumes of acid, add 5 cc. of ammonium hydroxide 
and shake out with four successive portioijs of chloroform, each of 50 cc. 
In case any dyestuff is removed by the chloroform, shake out with a satu- 
rated solution of sodium bisulphite, which will remove some of the color. 

Distil off the bulk of the chloroform and evaporate the remainder in a 
porcelain dish. Dissolve the residue in 25 cc. of 2% sulphuric acid, 
shake out with five portions of 15 cc. each of chloroform, filter the combined 
chloroform solutions into a flask, distil off the bulk of the chloroform and 
evaporate in a tared dish ; dry at 100° C. and weigh. 

* Mitt. Lebensm. Hyg., 8, 1917, p. 113. 

t U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 191. 



1018 FOOD INSPECTION AND ANALYSIS J 

If the caffein is not pure, dissolve in 15 cc. of 10% hydrochloric acid, 
add an excess of a solution of 10 grams of iodine and 20 grams of potas- 
sium iodide in 100 cc. of water, allow to stand overnight, filter, and wash 
twice with 10 cc. of the iodine solution. Transfer filter and precipitate 
to the original precipitation flask, add sufficient sulphurous acid to dissolve 
the precipitate, heating gently, filter into a separatory funnel, wash three 
times with water, and add ammonium hydroxide in excess; shake out 
four times with 15 cc. portions of chloroform, and filter the chloroform 
extracts into a flask, using a 7 cm. filter and keeping the funnel covered 
with a watch glass. Wash the filter with 5 portions of 5 cc. of chloroform. 
If the chloroform extract is colored, concentrate, add a small amount of 
animal charcoal, rotate several times and filter. Distil off part of the solvent 
and evaporate the remainder in a tared dish, dry at 100° C, and weigh. 

Detection and Determination of Cocaine. — Fuller Method* — To 
200 cc. of the sample in a large separatory funnel, add concentrated am- 
monium hydroxide to alkaline reaction, and shake out with three portions 
of 50 cc. each of Prolius mixture (4 parts ether, i part chloroform, i part 
alcohol), collecting the solvent in another separatory funnel. If desired 
the aqueous solution may be reserved for the detection of salicylic and 
benzoic acids and saccharin. Filter the combined Prolius extracts into 
an evaporating dish, and evaporate on a steam bath, removing the dish 
as the last traces of solvent disappear. Dissolve the residue in normal 
sulphuric acid, transfer to a separatory funnel and shake out four times 
with 15 cc. portions of chloroform; wash the combined chloroform solu- 
tions once with water, reject the chloroform, and add the water extract to 
the original acid solution. Add 10 cc. of petroleum ether, boiling at 40° 
to 50° C, and shake; draw off the acid layer, rejecting the petroleum ether, 
add concentrated ammonium hydroxide in excess and shake out three 
times with 15 cc. portions of petroleum ether, collecting the ethereal solu- 
tions in another separatory funnel. To the latter add 10 cc. of water and 
shake thoroughly; reject the water extract and filter the petroleum ether 
into a beaker, washing twice with 10 cc. portions of the solvent. Evaporate 
over a steam bath, using a fan. By this method, if coca alkaloids are 
present, a nearly colorless residue will be obtained, which will finally 
crystallize on standing. 

Dissolve the residue in petroleum ether and divide into four portions, 
one of which may be small. Evaporate the solvent and to the small 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 192. 



VEGETABLE AND FRUIT PRODUCTS. 1019 

portion add a few drops of normal sulphuric acid, warm gently, filter into 
a test-tube, and add a drop of potassium mercuric iodide test solution 
(Meyer's reagent). A precipitate indicates an alkaloid, but does not 
identify it as cocaine; if no precipitate forms, cocaine is not present and 
further test is unnecessary. 

To another portion add a few drops of concentrated nitric acid, and 
evaporate on a steam bath until the acid is all driven off, then add a few 
drops of half nornial alcoholic potash and note the first odor that comes 
off, which, if cocaine is present, is that of ethyl benzoate. 

The residue of the third portion should be applied to the end of the 
tongue by riibbing with the finger. Cocaine will cause a numbness which 
is not apparent immediately, but develops gradually, and persists for a 
longer or shorter time according to the amount present. 

Remove a portion of the fourth residue to a microscopic slide, add a 
drop or two of gold chloride test solution, and stir vigorously, noting the 
character of the crystals under the microscope. 

All the above tests should be checked by controls on pure cocaine. 

If a quantitative determination of coca alkaloids is desired the residue 
after evaporating the petroleum ether should be weighed, then, as a check 
on the gravimetric determination, warmed in 50 cc. of fiftieth-normal 
sulphuric acid until dissolved, cooled, and titrated with fiftieth-normal 
potassium or sodium hydroxide, using cochineal as indicator. The fac- 
tor for cocaine is 0.006018. 

Determination of Caffein and Detection of Cocaine and Glycerol. — 
Fuller Method.'^ — Weigh 50 grams of the sample into an evaporating dish, 
add 5 cc. of concentrated ammonium hydroxide, cover with a watch glass 
and allow to stand twelve hours. Add 2 cc. more of ammonium hydroxide 
and evaporate on steam bath. Warm the residue with 25 cc. of 95% 
alcohol on the steam bath, cool, and pour off the alcohol into another 
evaporating dish, repeating the treatment four times. Evaporate the 
combined alcoholic extract, dissolve the residue at 25 cc. of 2% sulphuric 
acid, transfer to a separatory funnel and shake out 5 times with 15 cc. 
portions of chloroform. 

Reserve the acid liquid for subsequent tests for cocaine and glycerol. 

Distil off most of the chloroform, evaporate in a dish on a steam bath, 
dissolve the residue in 10% hydrochloric acid and transfer to a small 
flask. Add to the acid solution an excess of iodine solution (10 grams 

* U. S. Dept. of Agric, Bur. of Chem., Bui. 137, p. 192. 



1020 FOOD INSPECTION AND ANALYSIS. 

iodine and 20 grams potassium iodide in 100 cc. of water), rotate flask, 
allow to settle overnight, filter, and wash flask and precipitate twice with 
the iodine solution, then transfer filter and precipitate to the flask. Heat 
gently with sufificient sulphurous acid solution to dissolve the precipitate, 
filter into a separatory funnel, cool, add excess of concentrated ammonium 
hydroxide, and shake out four times with 15 cc. portions of chloroform. 
Filter the chloroform extract into a flask, using a 7-cm. filter in a small 
funnel covered with a watch glass, or filter through cotton plugged in 
the stem of the separatory funnel. Decolorize the chloroform, if neces- 
sary, with animal charcoal, distil off most of the chloroform, then evapo- 
rate in a tared dish over steam, dry at 100° C. and weigh. 

Add an excess of concentrated ammonium hydroxide to the solution 
from which the cafTein was extracted, shake out three times with petroleum 
ether, boiling at 40° to 60° C, filter ether solution, divide into four parts, 
evaporate, and test for cocaine as described in the preceding method. 

Evaporate the aqueous solution from the cocaine extraction with 
milk of lime and proceed as in the determination of glycerol in wines 
(page 734) . The glycerol thus obtained will be only an approximation to 
the true amount. 



CHAPTER XXII. 

DETERMINATION OF ACIDITY BY MEANS OF THE HYDROGEN 

ELECTRODE. 

By Gerald L. Wendt, Ph.D. 

Assistant Professor of Chemistry, the University of Chicago. 

The usual methods of determining acid and alkali are frequently 
inapplicable in food analysis because the color change of the indicator, by 
means of which the end point is observed, is masked by the presence of 
colored substances or by turbidity. In such cases the use of the hydrogen 
electrode method is essential. Furthermore, there are many titrations in 
which it is not so important to know the total quantity of acid present as it 
is to determine exactly the concentration of hydrogen ions in the original 
solution. That is, it is desirable to determine the actual acidity as distinct 
from the total available acidity. A large part of the latter may be present 
originally in the form of undissociated molecules, and therefore inactive as 
acid until alkali is added. The hydrogen electrode method offers a simple 
means for such a determination. Finally, there are many occasions when 
the analyst wishes to prepare a solution of definite acidity which may t i 
far from the neutral point, and yet also far from being so acid or so alkaline 
as to be readily analysed. In such cases also the hydrogen electrode is 
of great convenience in that it indicates constantly the actual acidity of 
a solution at any moment, and acid or alkali need therefore to be added only 
until the instrument records the proper concentration. All three problems 
are frequently met with in courses of food analysis. 

In addition, indicator titrations are occasionally impossible because the 
salts present in the material to be titrated exert such a strong " buffer " 
action — as in milk, for instance, or in rhubarb juice — that the color change 
of the indicator is so gradual as to be quite unreliable. Related to this is 
the fact that the choice of the proper indicator is exceedingly important 
in such cases. The common indicators may all change at a degree of 
acidity which wholly unsuits them for some particular titration. And, 
lastly, the usual titration can give no information as to which acid or which 



1022 FOOD INSPECTION AND ANALYSIS. 

alkali is present in the solution that is being analysed. Thus fruit acids 
are empirically reported as per cent citric, malic or sulphuric regardless of 
the acid or mixture of acids present. On the other hand, the electro- 
metric method frequently reveals the characteristics of the acid that is being 
determined. For all these reasons, then, a simple form of the hydrogen 
electrode apparatus is to be recommended as part of the equipment of any 
food laboratory. 

Principle of the Method. — The first principle involved in this method 
of determining acidity is that every aqueous solution must have a definite 
concentration of hydrogen ions. Even pure water can be regarded as an 
acid, and equally well as an alkali, in the sense that water contains both 
hydrogen and hydroxide ions in definite concentration. The dissociation 
of water into its ions is weak, yet accurate measurements have shown that 
about one water molecule in five hundred million is dissociated into its ions. 
In other words, the concentration of hydrogen ions in water is very close to 
ID"'' grams per liter. Since each molecule of water on dissociation gives 
rise to one hydrogen ion and one hydroxide ion, the concentration of hydrox- 
ide ion in water is also io~'' gram ions per liter, i.e., both are io~'^ normal. 
The product of the two concentrations is consequently iq-^^ 

According to the simple principles of chemical equilibrium these two 
concentrations must bear a definite ratio toward each other at all times. 
That is, in the reaction represented by the equation H20^H++0H~, 
definite equilibrium concentrations of the reacting substances must always 
be obtained such that the velocity of the forward reaction is the same as 
that of the reverse action. This can be the case only if the concentration 
of hydrogen ions multiplied by the concentration of hydroxide ions be 
constant ; i.e., if, using the usual chemical symbols, (H+) (OH") = K = iq-i*. 
This constant is, of course, the dissociation constant of water, and represents 
the product of the concentrations of hydrogen and hydroxide ions expressed 
in normality. 

This constant must hold good for every solution which contains water, 
and thus for all aqueous solutions, irrespective of the amount of hydrogen 
or hydroxide ions added from other sources. That is to say, in a normal 
solution of a strong acid, the hydrogen ion concentration is one, or io°; 
substituted in the above equation, the hydroxide concentration must be 
io~i* in order that their product remain lo"^^. Similarly a hundredth 
normal solution of a strong acid would have a concentration of hydroxide 
equal to lo"^^. Strong acids therefore contain definite concentrations of 
hydroxide ions. At the other end of the scale, alkalis similarly contain 



DETERMINATION OF ACIDITY . 1023 

definite concentrations of hydrogen ions. The variation of hydrogen with 
hydroxide is represented in the following table : 







TABLE 


I. 










If (H+) = ioi 






(OH- 


) = 


= io-is 




Ph = 


— I 


loO 


(N) 








lo-i* 






o 


lo-i 


(O.I 


N) 






IO-13 






I 


10-2 


(o.oiN) 






IO-12 






2 


IO-3 










lo-ii 






3 


io-» 










lo-'o 






4 


lo-s 










IO-9 






5 


io-« 










IO-8 






6 


10-' 










lo-^ 






7 


IO-8 










IO-6 






8 


IO-9 










IO-6 






9 


io-i» 










lo-" 






lO 


IO-" 










IO~3 






II 


IO-12 










IO-2 (o. 


,oiN) 




12 


IO-" 










IQ-l (o. 


iN) 




13 


IO-" 










lo" (N) 




14 


10-15 










loi 






15 



The negative exponent of lo in these concentration figures for the hydrogen ion is the 
distinguishing factor for each case and has come to be used directly in this sense under the 
name of " Ph" 

Pure water stands in the center of this scale in that its hydrogen ion 
concentration is exactly equal to its hydroxide concentration, both being 
iQ-''. Water is therefore neutral, being as acid as it is basic. This is the 
exact neutral point, though it is seldom indicated by the indicators in general 
use. Most indicators will give either their " acid color " or their " alkali 
color " in water solution. Methyl orange, for instance, shows alkali in 
pure water, and phenolphthalein shows acid in pure water. Litmus and 
rosolic acid are two indicators that do change at the neutral point. 

While each indicator is suited for the determination of some one value 
of Ph, it is obvious that no one indicator can be used to follow the change 
of hydrogen and hydroxide ion concentration when a solution is titrated, 
i.e., when the hydrogen ion concentration may vary all the way from 
io~^ to lo"^"*. Each indicator has its own definite changing point, and 
will mark only the point at which that concentration is attained. The 
changing points for methyl orange and for phenolphthalein are indicated 
in Fig. 3. The hydrogen electrode method, however, records on a scale 
the concentration of hydrogen ions at all times, and it is thus possible to 
follow continuously the change beginning with strong acid all the way to 



1024 FOOD INSPECTION AND ANALYSIS. 

strong alkali or vice versa. The actual hydrogen ion concentration is in- 
dicated at every instant. 

Theory of the Method. — The theory of the hydrogen electrode is 
familiar. Its details need not be discussed here as they are available in 
any text-book of physical chemistry. Essentially the method consists 
in the measurement of the voltage between a platinum electrode saturated 
with hydrogen and the acid solution. The platinum electrode is coated with 
a layer of platinum black which is allowed to become saturated with hydro- 
gen gas. Hydrogen is readily soluble in platinum black so that such an 
electrode is essentially a " hydrogen electrode." That is, for all practical 
purposes it acts like a rod or electrode of hydrogen inserted into the solu- 
tion. The other electrode, which is to make direct contact with the solu- 
tion, i.e., with the hydrogen ions, must be one in which the transition from 
solution to the metallic connecting wire is made under definite and constant 
electrical conditions. For this purpose a " caloifiel cell " is used. Thereby 
the potential of the hydrogen ions is communicated to the rest of the system 
by, first, a solution of potassium chloride, then mercurous chloride, " cal- 
omel " solution, then calomel paste in contact with metallic mercury, 
which in turn contains the connecting wire. 

In such a system the potential between the coated platinum or hydrogen 
electrode and the mercury is given by the equation : 

£ = 0.058 log ('^U.283, 

where c represents the actual concentration of hydrogen ions in the solution. 

Transposing, log c = - / ^ j , 

_/ £-.283 \ 

E may then be read directly in volts on a voltmeter and the equation 
needs only to be solved for c or for Ph in order to give the hydrogen ion 
concentration or " actual acidity " of any unknown solution. The relation 
between E and c is linear, and the variation of one with the other may be 
calculated once for all and embodied in a table or curve, as is shown in the 
figures of this chapter. Indeed the voltmeter itself may conveniently 
be graduated to read in values of c directly, as well as in values of E. 
Titration consists then in following the change in £ as c is \'aried by 1I e 
addition of acid or alkali to the solution. 



and 



DETERMINATION OF ACIDITY 



1025 



The Apparatus. — The necessar}' apparatus consists of the hydrogen 
electrode, the calomel cell, and a potentiometer arrangement to measure 




Fig. i2oa. 



the potential between them. For accurate work an accurate potentiometer 
is necessary, but for the usual laboratory determinations a potentiometer can 



1026 



FOOD INSPECTION AND ANALYSIS. 



be readily built up from an ordinary dry cell, a loo-ohm variable resist- 
ance, a voltmeter, and a sensitive galvanometer which will determine when 
no current is passing. This galvanometer should have a sensitivity of one 
megohm. A diagram of the arrangement of these instruments is shown in 
Fig. i2ob and a photograph of a typical assembly in Fig. 120a. B represents 
a dry cell, and is connected directly through the resistance R, and a knife 
switch to form a complete circuit which must be closed whenever the 
instrument is in use. By means of the variable contact on the resistance, 
various potentials may be drawn from this main circuit and sent through the 




Fig. i2ob. 



side circuit, which comprises the calomel cell C, the solution to be titrated, 
the hydrogen electrode H, the galvanometer G, and a spring contact 
switch. The resistance is set at such a point that the galvanometer indicates 
the passage of no current. In that case, the potential being drawn from 
the main circuit is exactly equal and opposite to the potential from the 
hydrogen electrode-calomel electrode system. In order to measure this 
potential, a voltmeter V is placed in parallel with this side circuit, and at 
all times measures the potential. The procedure consists, therefore, simply 
in adjusting the resistance until on closing the contact key the galvanometer 
shows no current, and then reading the voltage. As suggested above, the 



DETERMINATION OF ACIDITY 1027 

voltmeter may be graduated to read directly in units of hydrogen ion con- 
centration rather than in volts. 

Details of the Apparatus. — i. The Hydrogen Electrode. — This is a plati- 
num wire I mm. in diameter, somewhat flattened at the lower end, which has 
been sealed into a small glass tube from which a copper wire leads to 
the rest of the circuit. This platinum wire must, when immersed in the 
solution, be about half covered by a larger tube which serves as a sort of 
bell to keep the upper half of the wire immersed in hydrogen gas while the 
lower half dips into the solution. The hydrogen is admitted to this bell- 
tube by a T-joint, and during operation bubbles continuously through 
the solution from under the bell at the rate of about two bubbles per 
second. The platinum wire must, before use and before insertion in the 
bell, be covered with a deposit of platinum black. This is done by first 
cleaning the wire thoroughly in chromic acid solution or in aqua regia if 
necessary. Platinum is then deposited on this wire by dipping it into a 
dilute solution of platinic chloride, and connecting the electrode to the 
negative pole of a dry cell, the positive being connected to another short 
piece of platinum wire which dips into the solution and forms the anode in 
the electrolysis. Deposition for fifteen minutes is ample, but it is desirable 
that the direction of the current be reversed frequently, as often as twice a 
minute, in order to give a smooth uniform coating of platinum, which should 
be black and velvety in appearance. The occluded chlorine may be 
removed by dipping the electrode into a ferrous or other reducing solution. 
The electrode is then washed with distilled water, and should thereafter 
always be kept moistened. When not in active use it should be kept in dis- 
tilled water. If the electrode dries, the platinum deposit must be wiped 
with a dry cloth or more thoroughly removed, and a new layer of platinum 
black must be deposited. The electrode in this condition will absorb 
hydrogen from hydrogen gas and constitute in effect a hydrogen electrode. 
Time may be economized however, by saturating the electrode with 
hydrogen artificially by using this electrode as the cathode in an electrol- 
ysis of sulphuric acid. Hydrogen is thus evolved on the cathode, and serves 
to saturate it rapidly. This saturation should be repeated whenever the 
electrode is removed from its contact with pure hydrogen gas. The coat- 
ing with platinum black should be serviceable for several weeks before 
it requires replacement. If solutions containing viscous materials or adher- 
ing precipitates are used, the platinum layer needs to be replaced more often. 

This form of electrode may be purchased from supply houses. Other 
forms are also in use, particularly some in which the platinum is in the form 



1028 FOOD INSPECTION AND ANALYSIS. 

of a large foil or strip. This form is more stable in use but requires a much 
longer time to become saturated with hydrogen and is troublesome in 
solutions containing precipitates or other solid or viscous materials such 
as cream or fruit shreds. For such cases a fine platinum gauze may be 
attached to the glass bell that surrounds the electrode to prevent its clog- 
ging, particularly if some stirring device is used. A gold electrode coated 
with palladium black is probably the most effective form of hydrogen elec- 
trode. 

2. The Calomel Electrode.— A calomel electrode may be made up by 
any of the various methods recommended in text-books of physical chem- 
istry. The forms of cell used vary widely. The simplest is a test-tube 
with a two-hole rubber stopper, fitted with tubes, one of which leads to the 
solution to be titrated, and the other of which holds a glass tube forming 
electrical connection with the mercury in the bottom of the test-tube by 
means of a wire sealed through the glass. The form to be recommended 
is one in which electrical connection from the mercury is made by a platinum 
wire sealed directly through the glass where the latter holds the mercury. 
The tube should have a side-arm forming a bridge to the solution, and unless . 
a fine capillary is used, this side-arm should contain a glass stop-cock 
which is kept loosely closed but not greased. The calomel electrode tube 
should have another side-arm placed somewhat higher through which 
additional potassium chloride solution can be introduced. Finally, it 
should have a wide opening through which it can be filled, but which 
should be tightly closed after filling by means of a well-fitting ground 
glass stopper. 

To fill the cell it should be thoroughly cleaned and rinsed with a normal 
potassium chloride solution. About 3 cc. of carefully purified mercury 
are then placed in the bottom of the cell. Above this is put a layer of mer- 
cury-calomel paste. This is prepared by rubbing together in a mortar 
pure " calomel," mercurous chloride, and metallic mercury with a small 
amount of the potassium chloride solution. When this paste is in place 
it is covered with a normal solution of potassium chloride which has been 
saturated with calomel. A large quantity of accurately normal potassium 
chloride solution should.be made up, and after preparation should be 
thoroughly shaken with calomel in order to saturate it with that substance. 
The calomel electrode tube should then be filled up with this solution, 
leaving only a small air bubble at the top. The tube should be well 
stoppered, and permanent connection should be made through the upper 
side-arm with a reservoir bottle containing the excess of potassium chloride 



DETERMINATION OF ACIDITY 1029 

solution. Before each period of use a small quantity of the potassium 
chloride solution should be allowed to run through the calomel cell in order 
to wash out the lower side-arm, which constitutes the electrical connection 
with the solution to be titrated, and which will otherwise gradually 
become filled with materials from the latter solution by means of 
diffusion. 

3. The Electrical Instruments.— Thr^t electrical instruments are re- 
quired, connected as shown in Fig. \2oh, a variable resistance, a voltmeter, 
and a galvanometer. There are many varieties of resistances or rheostats 
on the market. Any form which permits the continuous ^'ariation of the 
resistance is satisfactory. The tubular wire rheostats of about 100 ohms 
total resistance are most convenient, but should be long enough to have at 
least 150 turns of wire in order to allow delicate adjustment of the end point. 
The voltmeter should have a total range of 1.25 volts, which is the maximum 
obtainable from a dry cell, and should be divided into hundredths of volts. 
The galvanometer, or other instrument used to detect the passage of cur- 
rent through the solution being titrated, is the only one of these instruments 
that needs to be sensitive. It should have a sensitivity of at least i megohm. 
There are several types of portable direct-reading galvanqmeters on the 
market with a sensitivity as great as this. By the use of the lamp and scale 
method, more sensitive and more expensive instruments may also be used 
with convenience. In very accurate work in which, potential readings are 
to be made to millivolts, some form of electrometer is often used, such as the 
capillary electrometer or the quadrant electrometer. These are not rec^uired, 
however, for ordinary titration. The connections are shown in Fig. 1206, 
which is self-explanatory. It should be noted, however, that the short 
thick line of the battery, B, represents the positive or carbon pole of the 
dry cell. It is to this pole that the positive terminal of the voltmeter and 
the calomel cell connection are made. 

Several complete assemblies of this apparatus are on the market. The 
most accurate, which can be depended upon to millivolts, is that designed 
by Dr. W. T. Bovie and manufactured by the Leeds & Northrup Co., of 
Philadelphia. This makes use of the quadrant electrometer, and is pro- 
vided with a temperature compensating device. An apparatus designed by ' 
Dr. G. L, Kelley, can also be adapted to this purpose, and is sold by 
Arthur H. Thomas, of Philadelphia, Pa. The Central Scientific Co., of 
Chicago, has assembled the simplest forms of the various required in- 
struments on a single board, the result being inexpensive and well suited 
for ordinary analytical work. 



1030 FOOD INSPECTION AND ANALYSIS. 

The Titration. — The solution to be titrated is placed in a sufficiently 
large beaker, the calomel electrode as above prepared is inserted, and the 
hydrogen electrode, platinized and saturated with hydrogen, is also inserted. 
A stream of hydrogen is allowed to pass over the hydrogen electrode and 
bubble through the solution continuously during the titration. The 
hydrogen should be pure, best made by electrolysis or generated from pure 
zinc and purified by passing through an alkaline solution. It is usually 
desirable to stir the solution by some extraneous stirring device. Electrical 
connections are made and preliminary observations of the voltage may be 
taken, although at the beginning of the titration the electrode is usually 
not saturated and does not give a constant \oltage reading during the first 
few minutes. If the electrode has been saturated by means of the elec- 
trolysis of sulfuric acid, however, not more than a minute should be required 
to determine the original P^ or " actual acidity." If the solution is to be 
titrated acid or alkali may now be added, and readings of the voltage 
may be taken almost at once. The electrode action is most satisfactory 
when the potential is built upwards, that is, when alkali is added to acid. 
Beginning with a definite quantity of acid, the data to be recorded are the 
amounts of alkali added and the voltage at each addition. These data are 
best comprehended by plotting them graphically, recording voltage against 
cubic centimeters of alkali added. Several such curves are reproduced here- 
with. 

T3T)ical Curves. — Curve I, Fig, 120c, represents the titration of 25 cms. 
of tenth-normal hydrochloric acid solution with tenth-normal sodium 
hydroxide. Ordinates on this curve represent acidity. The voltage 
scale is represented on the left while the corresponding concentrations 
of hydrogen ions are given on the right. The voltage 0.69 is that of the 
neutral point, where (H+) = (0H~) = io~'^. The higher the voltage, 
the lower the hydrogen ion concentration and the greater the alkalinity. 
The abscissas represent volumes of the alkaline solution added. 

The original voltage shown by Curve I is 0.35, which represents a 
tenth-normal hydrogen ion concentration. The curve shows that the first 
quantities of alkali added have little effect on the hydrogen ion concentra- 
tion. The alkali is used up in the formation of sodium chloride and the 
fraction of the total acid used is so small that there is little change in the 
hydrogen ion concentration and in the voltage. As more and more acid is 
neutralized, however, every drop of alkali causes a correspondingly larger 
proportional change in the hydrogen ion concentration and the voltage rises 
more and more-rapidly. When a voltage of .45 is attained and the acid 



DETERMINATION OF ACIDITY 



1031 



is less than one-thousandth normal the addition of a few drops of alkali 
causes so marked a change in the hydrogen ion concentration that the 
voltage rises rapidly and indeed abruptly. At 24.8 cc. of alkali, the poten- 
tial rises to beyond the neutral pomt and this quantity of alkali therefore 
represents the total amount of acid originally present. This figure, 24.8, 
is the one that would be obtained by the usual indicator titration and 
represents the amount of tenth-normal alkali necessary to neutralize the acid 
originally present. The acid was therefore very slightly weaker than tenth- 
normal. Beyond this point the addition of alkali increases the hydroxide ion 



1.1 
1.0 
0.9 
0.8 



0O.7 



0.6 
0.5 
0.4 
0.3 





Curve I. 26 C.C. N/10 11 CI 
Curvell. 25C.C. N/10 HC2H3O2 

1 

"Neutral Point" 










Phenolphthalein_ 
changes 

Litmus 


— > 


10-" 


10-^° 


10-" 


io-« 


10-^ 


1 


1 1 1 1 1 1 I 1 1 "I 1 


changes ~ 

Methyl Orange_ 
changes 

1 1 1 1 I 1 1 


->• 
1 


10-" 


10-^ 


10-* 


10- « 


10-=' 





2 -1 G 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 
C.C. of N/10 Na OH 
Fig. 1 20c. 



concentration and decreases the hydrogen concentration in a lesser propor- 
tion and the voltage therefore rises more gradually, tending finally to reach 
the voltage of a tenth-normal alkali solution, which is slightly less than i 
volt. The further addition of alkali is, however, unnecessary, as the last 
part of the curve represents merely the dilution of tenth-normal alkali by 
the volume of solution present in the titrating vessel. 

The center of the vertical rise in voltage at about 25 cc. of alkali needs 
further attention. It will be seen that the central point of the vertical 
line lies at a voltage of about .69. This is the voltage given by a strictly 
neutral solution and it indicates the point at which hydrogen and hydroxide 



1032 FOOD INSPECTION AND ANALYSIS. 

ions are in equal concentration. Since the central part of the vertical rise 
of this curve here falls exactly at the true neutral point it follows that the 
products of the reaction here used are such that they do not react v^^ith water 
to give a product which is itself acid or alkaline. The products of the 
particular reaction shown by this curve are, of course, sodium chloride 
and water, and it is obvious that sodium chloride does not hydrolyze to give 
an acid or a basic product. 

Curve 2, Fig. 120c, shows the titration of the same quantity of tenth- 
normal acetic acid with the same alkaline solution. The curve shows that 
the same quantity of alkali is required for neutralization and hence that the 
total acidity of the acetic acid was the same as that of the hydrochloric acid, 
both being tenth-normal. The course of the voltage during the early 
part of the titration, however, is quite different in this case. In the first 
place, the original voltage is higher, indicating a lower actual hydrogen 
ion concentration in the tenth-normal acetic acid, due, of course to the fact 
that acetic acid is but slightly dissociated. Its " actual acidity " is, indeed 
hardly more than thousandth normal. The second point worthy of notice 
is that in the very beginning of the titration the rise in voltage is much more 
rapid than in the case of the hydrochloric acid. This means that the 
addition of alkali has here an abnormally large effect in decreasing the hydro- 
gen ion concentration. This is due, of course, to the fact that as soon as 
sodium hydroxide is added, sodium acetate is formed which is highly 
dissociated and therefore liberates a relatively large number of acetate 
ions. These, according to the principle of equilibrium have an immediate 
effect in depressing the already small ionization of the acetic acid, so that 
the acid which is present becomes still less dissociated ; hence it allows still 
fewer hydrogen ions and hence causes a noticeable rise in the voltage. 
This effect is marked only during the first 8 cc. and thereafter the trend of 
the curve is about the same as that in the titration of hydrochloric acid. 
Complete neutralization occurs at the same point, and the last part of the 
curve coincides with that of the hydrochloric acid since it represents only 
the dilution of the tenth-normal sodium hydroxide by the sodium acetate 
solution. 

A third point to be noted is that the length of the vertical portion of this 
curve is much less than in the other case with the consequence that the 
center of this vertical portion lies not at a voltage of .69 but rather at about 
.76 volt. Now the center of the vertical portion represents the hydrogen 
ion concentration when exactly equivalent quantities of sodium hydroxide 
and of acetic acid are present ; that is, it represents the conditions when only 



DETERMINATION OF ACIDITY 1033 

water and sodium acetate are present. But sodium acetate hydrolyzes 
to some extent in water solution giving rise to undissociated acetic acid and 
thus allowing freedom to an excess number of hydroxide ions. In common 
terms, sodium acetate gives a basic reaction. This reaction is indicated on 
this curve by the fact that the center of the vertical position of the curve is 
at .76 volt, corresponding to a hydrogen ion concentration between 10 -» 
and io~^. 

For this titration phenolphthalein is usually employed as indicator. 
The concentration of hydrogen ion, at which this indicator changes, is seen 
from Fig. 120c to be such that it is well suited for this purpose. It does not 
change color at the neutral point, but it does change at a point corresponding 
to the hydrogen ion Concentration of a solution of sodium acetate in water. 
It is therefore the correct indicator for this purpose. Litmus would not 
do. Nor would methyl orange, which changes quite on the acid side of 
neutrality, and is therefore fitted only for titrations of strong acids with 
weak bases, since these give salts which hydrolyze in water to liberate 
hydrogen ions, and thus have an " acid reaction." 

The Titration of Milk. — The curves on Fig. 1 2od represent titrations car- 
ried out with a sample of milk at various times. Curve i represents the 
addition of tenth-normal sodium hydroxide to 25 cc. of fresh milk. The 
original voltage is .68. The milk is therefore very slightly acid — almost 
imperceptibly so. The true neutral point is reached with 1.5 cc. of alkali, 
but it is doubtful whether this quantity has any actual significance, for the 
steepest rise in the curve comes later at about 5.5 cc. and a voltage of 0.8. 
This is probably the point corresponding to sodium lactate. Thereafter, 
the rise of the curve is more gradual, but the entire curve is notably more 
flattened than "the curves of the strong acids heretofore used. This is no 
doubt due to the presence of salts, especially the salts of weak alkalis and 
weak acids like the calcium phosphates. The data obtained from this 
curve are more reliable than those obtained by the usual indicator titrations 
used in commercial laboratories. The first point, for instance, is usually 
determined by the use of litmus, which changes very gradually, and gives a 
much less accurate determination of the actual hydrogen ion concentration. 
The second point is determined by the use of phenolphthalein which changes 
at an acidity corresponding to a voltage of .8. The opacity of milk hinders 
an accurate determination of the color change. 

The same sample of milk was kept on ice and its actual hydrpgen ion 
concentration was determined from day to day. The voltage varied as 
follows : 



1034 



FOOD INSPECTION AND ANALYSIS. 



On June i8. 

" 19. 
" 20. 
" 21. 

" 24. 



68 
66 
60 
58 
56 
54 



After a week, therefore, the acidity had increased so that the milk showed 
a hydrogen ion concentration of about 10 ~^, that is, the milk was ten- 



1.1 

1 


:/ 


^^ "Neutral Point" 






10-12 








10-" 


0.9 


io-^» 




io-« 


0.8 


10"* 


5 
0.7 


10-' 


> 


1 1 1 1 


Curve I Fresh Milk 
Curve II Same Milk 
Curve III Same Milk 

1 1 1 1 1 1 1 1 1 1 


6/18 

6/23 
6/24 

1 1 1 


1 1 


10"^ 


O.G 


10-^ 




10-* 


0.5 


io-» 


0.4 


lo-'' 


ft ^ 





2 4 6 8 10 12 14 IC 18 20 22 24 2G 28 30 32 34 36 38 40 
C.C. Of N/lONaOH 
Fig. i2Qd. 

thousandth normal in actual hydrogen ion concentration. This acidity, 
however, is due to lactic acid which is but slightly dissociated and the total 
acid present is undoubtedly more than this quantity. That this is true is 
shown by curves 2 and 3 of Fig. 1 20^, which represent titrations carried out 
on this sample on June 23 and June 24 respectively. The general form 
of these curves is the same as that of the first titration on this sample, being, 
however, somewhat more flattened. Total neutralization of the acid is 
reached again at about .8 volt corresponding to 18.6 cc. of alkali on June 
23d. By the next day 22.3 cc. were rccjuired to reach the same voltage. 
The difference is a measure of the growth of lactic acid during the twenty- 



DETERMINATION OF ACIDITY 



1035 



four hours that had elapsed. The original \'oltage or '' actual acidity " 
is, however, an equally good measure of the souring of the milk, and can be 
readi'ly and speedily determined. 

Wlie.i milk has become sour or when it is rich in cream, the electrode 
tends to become clogged with the solid materials unless it is protected by a 
gauze as suggested above. 

Tea and Coffee.— Fig. 1 2oe represents the titration of samples of tea and 
coffee brews. Coffee is obviously more acid both in its actual hydrogen 
ion concentration, which is fairly high, and in its total acid. The curve 



1.1 




TT •'•• * 




- 10-^^ 


1.0 


"Neutral Point" 


' j 10-" 


0.9 


io-^» 




'■ , 10-" 


0.8 


10"* 


O0.7 


10-^ 


> 


1 1 


Curve I 
Curve H 

1 1 1 1 1 r 


Tea 
Coffee 

1 I 1 f 1 


10-® 


0.6 


10-5 


0.5 


10-* 

10"^ . 


0.4 


10-^ ' 


n ^ 


II' 



4 6 8 10 12 14 16 18 20 22 24 26 28 30 
C.C. of N/lONaOH 

Fig. i2oe. 



for tea, on the other hand, is much flatter and indicates thepresenceof weaker 
acids and of more basic salts. The interesting portions of these titrations 
are in the voltages lying between 0.6 and 0.8 and the titration should be 
carried on with hundredth -normal alkali instead of with tenth-normal. 

The Acidity of Fruit Juices. — For the titration of fruit juices, these are 
prepared in the usual way by pressing out the juice and straining through a 
fine cloth or filter. In all cases represented here by curves 25 cc. of fruit 
juice were used, though it is possible and often necessary to use a smaller 
quantity. The analyses represented are single instances chosen at random 
and make no claim to being representative for the different varieties of fruit. 



1036 



FOOD INSPECTION AND ANALYSIS. 



Lemon and Strawberry. — Fig. 120/ represents the titration of two common 
acid fruits, the lemon and the strawberry. It is noticeable that the actual 
acidity of the strawberry is greater than that of the lemon, being more than 
hundredth-normal. Yet the total acidity of the lemon is almost five times 
that of the strawberry. Twenty-five cc. of fruit juice were taken; hence 
the lemon is almost normal in total acid in that 22 cc. of normal alkali 
were required to neutralize it. The curve for the lemon is a typical curve 
for citric acid. The long sloping portion of the curve running from zero 
to 20 cc. represents the gradual neutralization of the three hydrogens that 
comprise the acid of this fruit. No distinct vertical parts of the curve 



1.1 




f 


"Neutral Point" I 


f 


• 

10-12 


i.O 


10-" 


0.9 


10-1" 




io-» 


08 


10"* 


0.7 


10"^ 




1 

f 


f 

1 I 1 


Curve I 
Curve II 

1 1 I 1 1 1 1 


Lemon Juice 
Strawberry Juice 

1 1 1 1 1 1 1 1 


10"® 


0.6 


10^ 


0.5 


10-* ' ' 


10"^ 


0.4 


. 10-2 


n ■? 


1 



2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 
CC. of N/1 Na OH 

Fig. i2o/. 

are noticed because the reaction of the second hydrogen begins before 
that of the first is complete, and that of the third also begins very soon. 

The Citric Fruits. — Fig. 1 2og shows this same titration of the strawberry 
as executed with one-tenth normal alkali. On the same figure appear the 
curves representing the orange, the grape fruit and the tomato. The straw- 
berry is the most acid of these four fruits, especially in its actual acidity. 
Citric, salicylic and malic acids are present. The total acid of the orange 
is greater than that of the grapefruit though its actual acidity is less. The 
flat appearance of the orange curve marks the presence of other salts. The 



DETERMINATION OF ACIDITY 



1037 



general slanting appearance of the tomato curve is explained by the complex- 
ity of its acid constituents. 



1.1 

1.0 


— 


IZ--^ 






10-^^ 


0.9 

0.8 

•^0.7 


y y 




: 10 

io-'» 

' 10-* 

10-* 

10-^ 


0.6 


^^^^ 




Curve r. 
Curve II. 
Curve III. 
Curve IV. 
1 1 1 1 1 


Strawberry Juice 
Orange Juice 
Grape Fruit Juice 
Tomato Juice 

1 1 1 1 1 1 1 1 


10-" 

10-^ 


0.5 


5S====^^^^^^^^ *" 




10 


0.4 

51 


1 1 1 1 [ 1 1 


1 1 1 r 1 r 1 1 1 


10"* 
10"^ 



"02468 10 12 14_16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 GO 
C.C. of N/10 NaOH 

Fig. i2og. 

It will be noted of all these titrations that the acids are weak and other 
salts are plentiful. The abrupt rise at the very beginning of the curve always 




Curve I. 
Curve II. 
Curve III. 
Curve IV. 
Curve V. 



Peach Juice 
Cherry Juice 
Plum Juice 
Banana Juice 
Apple Juice. 



^■^ 2 4 6 8 10 12 U 16"l8 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 

C.C. of N/10 NaOH 
Ftg. i2oh. 

points to the presence of an undissociated acid. In every case the center 
of the vertical portion of the curve lies on the alkaline side of the neutrality 
line. The exact position of this point would be a means of identifying the 



1038 FOOD INSPECTION AND ANALYSIS. 

acid present, for the weaker the acid the higher is the voltage given by 
the sodium salt in water. So many acids and other salts are present, 
however, that the curves show much " buffer action," i.e., they show few 
sharp flexions and it is not easy to locate the point of equivalence. For the 
same reason, however, any indicator would give only an arbitrary and 
empirical value of the equivalence point, and is even less well adapted to 
showing what is really present. 

The Malic Fruits. — Fig. i2oh represents the malic fruits. Of these the 
peach is most acid (though this may possibly have been due to the use of an 
unripe sample in this analysis). The apple and the cherry have the same 



1.1 

1.0 

0.9 

0.8 

3 0.7 

0.6 



S 



0.5 
0.4 
0.3 



Curve I. Valencia Orange after One Week on Ice 

Curve II. Same after One Week at Room Temperature 

Curve III. "Special St.Michaelis" Redlands Orange after One Week on Ice 

Curve IV. Same after One Week at Room Temperature 

J I 1 I I 1 I [ \ I l_J I I I I I I I I I I I I I I I 1 I L 



10 



2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 
C.C. of N/10 NaOH 

Fig. I20Z. 

actual acidity, but are widely different in the total amounts of acid avail- 
able. The curve for the apple is a simple curve indicating the presence of 
only one type of acid and few salts. The plum and the cherry curves are 
extraordinarily flat and hence these fruits are complex in their constitution. 
The banana, as is well known, is among the least acid of the common 
fruits. 

The Effect of Ripening. — Fig. 120/ finally shows the effect of ripening in 
decreasing the fruit acidity. Here Curves i and 2 represent juice from two 
samples of Valencia orange, one of which was kept on ice for a week while 
the other was kept at room temperature. The marked change in acidity 
shows an effectual ripening in the second case. Precisely the same is shown 
by Curves 3 and 4 of this figure, which represents a similar experiment with 



DETERMINATION OF ACIDITY 1039 

two samples of Redlands orange. The peaches represented in Fig. 120^ 
appeared to be ripe but the curve indicates unripeness since this fruit is 
not usually so acid. Ripeness is thus a factor that needs to be determined 
before such a curve can be considered representative for any fruit. Finally, 
this hydrogen electrode method is a useful means of determining 
ripeness. 



APPENDIX. 



THE FOOD AND DRUGS ACT, JUNE 30, 1906, AS AMENDED AUGUST 23, 1912 

AND MARCH 3, 1913. 

AN ACT FOR PREVENTING THE MANUFACTURE, SALE, OR TRANSPORTATION OF ADULTERATED 
OR MISBRANDED OR POISONOUS OR DELETERIOUS FOODS, DRUGS, MEDICINES, AND LIQUORS, 
AND FOR REGULATING TRAFFIC THEREIN, AND FOR OTHER PURPOSES. 

Be it enacted by the Senate and House of Representatives of the United States of America 
in Congress assembled, That it shall be unlawful for any person to manufacture within 
any Territory or the District of Columbia any article of food or drug which is adulterated 
or misbranded, within the meaning of this Act; .and any person who shall violate any 
of the provisions of this section shall be guilty of a misdemeanor, and for each offense shall, 
upon conviction thereof, be fined not to exceed five hundred dollars or shall be sentenced 
to one year's imprisonment, or both such fine and imprisonment, in the discretion of the 
court, and for each subsequent offense and conviction thereof shall be fined not less than 
one thousand dollars or sentenced to one year's imprisonment, or both such fine and imprison- 
ment, in the discretion of the Court. 

Sec. 2. That the introduction into any State or Territory or the District of Colum- 
bia from any other State or Territory or the District of Columbia, or from any foreign coun- 
try, or shipment to any foreign country of any article of food or drugs which is adulterated 
or misbranded, within the meaning of this Act, is hereby prohibited; and any person who 
shall ship or deliver for shipment from any State or Territory or the District of Columbia 
to any other State or Territory or the District of Columbia, or to a foreign country, or 
who shall receive in any State or Territory or the District of Columbia from any other 
State or Territory or the District of Columbia, or foreign country, and having so received, 
shall deliver, in original unbroken packages, for pay or otherwise, or offer to deliver to 
any other person, any such article so adulterated or misbranded within the meaning of this 
Act, or any person who shall sell or offer for sale in the District of Columbia or the Ter- 
ritories of the United States any such adulterated or misbranded foods or drugs, or export 
or offer to export the same to any foreign country, shall be guilty of a misdemeanor, and 
for such offense be fined not exceeding two hundred dollars for the first offense, and upon 
conviction for each subsequent offense not exceeding three hundred dollars or be imprisoned 
not exceeding one year, or both, in the discretion of the court: Provided, That no article 
shall be deemed misbranded or adulterated within the provisions of this Act when intended 
for export to any foreign country and prepared or packed according to the specifications 
or directions of the foreign purchaser when no substance is used in the preparation or pack- 
ing thereof in conflict with the laws of the foreign country to which said article is intended 
to be shipped; but if said article shall be in fact sold or offered for sale for domestic use 
or consumption, then this proviso shall not exempt said article from the operation of any 
of the other provisions of this Act. 

Sec. 3. That the Secretary of the Treasury, the Secretary of Agriculture, and the 
Secretary of Commerce and Labor shall make uniform rules and regulations for carrying 
out the provisions of this act, including the collection and examination of specimens of 
foods and drugs manufactured or offered for sale in the District of Columbia, or in any 

1041 



1042 FOOD INSPECTION AND ANALYSIS. 

Territory of the United States, or which shall be offered for sale in unbroken packages in 
any State other than that in which they shall have been respectively manufactured or pro- 
duced, or which shall be received from any foreign country, or intended for shipment to any 
foreign country, or which may be submitted for examination by the chief health, food, or 
drug officer of any State, Territory, or the District of Columbia, or at any domestic or foreign 
port through which such product is offered for interstate commerce, or for export or import 
between the United States and any foreign port or country. 

Sec. 4. That the examinations of specimens of foods and drugs shall be made in the 
Bureau of Chemistry of the Department of Agriculture, or under the direction and super- 
vision of such Bureau, for the purpose of determining from such examinations whether 
such articles are adulterated or misbranded within the meaning of this Act; and if it shall 
appear from any such examination that any of such specimens is adulterated or misbranded 
within the meaning of this Act, the Secretary of Agriculture shall cause notice thereof to 
be given to the party from whom such sample was obtained. Any party so notified shall 
be given an opportunity to be heard, under such rules and regulations as may be prescribed 
as aforesaid, and if it appears that any of the provisions of this Act have been violated 
by such party, then the Secretary of Agriculture shall at once certify the facts to the 
proper United States district attorney, with a copy of the results of the analysis or the 
examination of such article duly authenticated by the analyst or ofi&cer making such 
examination, under the oath of such officer. After judgment of the court, notice shall be 
given by publication in such manner as may be prescribed by the rules and regulations 
aforesaid. 

Sec. 5. That it shall be the duty of each district attorney to whom the Secretary of 
Agriculture shall report any violation of this Act, or to whom any health or food or drug 
ofl&cer or agent of any State, Territory, or the District of Columbia shall present satisfactory 
evidence of any such violation, to cause appropriate proceedings to be commenced and 
prosecuted in the proper courts of the United States, without delay, for the enforcement 
of the penalties as in such case herein provided. 

Sec. 6. That the term " drug," as used in this Act, shall include all medicines and 
preparations recognized in the United States Pharmacopoeia or National Formulary for 
internal or external use, and any substance or mixture of substances intended to be used 
for the cure, mitigation, or prevention of disease of either man or other animals. The 
term " food," as used herein, shall include all articles used for food, drink, confectionery, 
or condiment by man or other animals, whether simple, mixed, or compound. 

Sec. 7. That for the purposes of this Act an article shall be deemed to be adulterated: 

In case of drugs: 

First. If, when a drug is sold under or by a name recognized in the United States Phar- 
macopoeia or National Formulary, it differs from the standard of strength, quality, or 
purity, as determined by the test laid down in the United States Pharmacopoeia or National 
Formulary official at the time of investigation: Provided, That no drug defined in the United 
States Pharmacopoeia or National Formulary shall be deemed to be adulterated under this 
provision if the standard of strength, quality, or purity be plainly stated upon the bottle, 
box, or other container thereof although the standard may differ from that determined by 
the test laid down in the United States Pharmacopoeia or National Formulary. 

Second. If its strength or purity fall below the professed standard or quality under 
which it is sold. 

In the case of confectionery: 

If it contain terra alba, barytes, talc, chrome yellow, or other mineral substance or 
poisonous color or flavor, or other ingredient deleterious or detrimental to health, or any 
vinous, malt, or spirituous liquor or compound or narcotic drug. 

In the case of food: 



APPENDIX. 1043 

First. If any substance has been mixed and packed with it so as to reduce or lower or 
injuriously affect its quality or strength. 

Second. If any substance has been substituted wholly or in part for the article. 

Third. If any valuable constituent of the article has been wholly or in part abstracted. 

Fourth. If it be mixed, colored, powdered, coated, or stained in a manner whereby 
damage or inferiority is concealed. 

Fifth. If it contain any added posionous or other added deleterious ingredient which 
may render such article injurious to health: Provided, That when in the preparation of food 
products for shipment they are preserved by any external application applied in such manner 
that the preservative is necessarily removed mechanically, or by maceration in water, or 
otherwise, and directions for the removal of said preservative shall be printed on the cov- 
ering or the package, the provisions of this Act shall be construed as applying only when said 
products are ready for consumption. 

Sixth. If it consists in whole or in part of a filthy, decomposed, or putrid animal or 
vegetable substance, or any portion of an animal unfit for food, whether manufactured or 
not, or if it is the product of a diseased animal, or one that has died otherwise than by 
slaughter. 

Sec. 8. That the term " misbranded," as used herein, shall apply to all drugs, or articles 
of food, or articles which enter into the composition of food, the package or label of which 
shall bear any statement, design, or device regarding such article, or the ingredients or 
substances contained therein which shall be false or misleading in any particular, and to 
any food or drug product which is falsely branded as to the State, Territory, or country in 
which it is manufactured or produced. 

That for the purposes of this Act an article shall also be deemed to be misbranded: 

In case of drugs: 

First. If it be an imitation of or offered for sale under the name of another article. 

Second. If the contents of the package as originally put up shall have been removed, 
in whole or in part, and other contents shall have been placed in such package, or if the 
package fail to bear a statement on the label of the quantity or proportion of any alcohol, 
morphine, opium, cocaine, heroin, alpha or beta eucaine, chloroform, cannabis indica. 
chloral hydrate, or acetanilide, or any derivative or preparation of any such substances 
contained therein. 

Third.* If its package or label shall bear or contain any statement, design, or device 
regarding the curative or theraupetic effect of such article or any of the ingredients or sub- 
stances contained therein, which is false and fraudulent. 

In the case of food: 

First. If it be an imitation of or offered for sale under the distinctive name of another 
article. 

Second. If it be labeled or branded so as to deceive or mislead the purchaser, or pur- 
port to be a foreign product when not so, or if the contents of the package as originally 
put up shall have been removed in whole or in part and other contents shall have been 
placed in such package, or if it fail to bear a statement on the label of the quantity or propor- 
tion of any morphine, opium, cocaine, heroin, alpha or beta eucaine, chloroform, cannabis 
indica, chloral hydrate, or acetam'Jide, or any derivative or preparation of any of such sub- 
stances contained therein. 

Third, t If in package form, the quantity of the contents be not plainly and con- 
spicuously marked on the outside of the package in terms of weight, measure, or numer- 
ical count: Provided, however, That reasonable variations shall be permitted, and toler- 
ances and also exemptions as to small packages shall be established by rules and 

* This paragraph constitutes the amendment of August 23, 1912. 
t This paragraph is as amended March 3, 19 13- 



1044 FOOD INSPECTION AND ANALYSIS. 

regulations made in accordance with the provisions of Section three of this Act. That 
this Act shall take effect and be in force from and after its passage: Provided, however 
That no penalty of fine, imprisonment, or confiscation shall be enforced for any violation 
of its provisions as to domestic products prepared or foreign products imported prior to 
eighteen months after its passage. 

Fourth. If the package containing it or its label shall bear any statement, design, or 
device regarding the ingredients or the substances contained therein, which statement, 
design, or device shall be false or misleading in any particular: Provided, That an article 
of food which does not contain any added poisonous or deleterious ingredients shall not 
be deemed to be adulterated or misbranded in the follo\ving cases: 

First. In the case of mixtures or compounds which may be now or from time to time 
hereafter known as articles of food, under their own distinctive names, and not an imitation 
of or offered for sale under the distinctive name of another article, if the name be accom- 
panied on the same label or brand with a statement of the place where said article has been 
manufactured or produced. 

Second. In the case of articles labeled, branded, or tagged so as to plainly indicate 
that they are compounds, imitations, or blends, and the word " compound," " imitation," 
or " blend," as the case may L^, is plainly stated on the package in which it is offered for 
sale: Provided, That the term blend as used herein shall be construed to mean a mixture 
of like substances, not excluding harmless coloring or flavoring ingredients used for the pur- 
pose of coloring and flavoring only: And provided further, That nothing in this Act shall 
be construed as requiring or compelling proprietors or manufacturers of proprietary foods 
which contain no unwholesome added ingredient to disclose their trade formulas, except 
in so far as the provisions of this Act may require to secure freedom from adulteration or 
misbranding. 

Sec. q. That no dealer shall be prosecuted under the provisions of this Act when he 
can estabhsh a guaranty signed by the wholesaler, jobber, manufacturer, or other party 
residing in the United States, from whom he purchases such articles, to the effect that 
the same is not adulterated or misbranded within the meaning of this Act, designating it. 
Said guaranty, to afford protection, shall contain the name and address of the party or 
parties making the sale of such articles to such dealer, and in such case said party or parties 
shall be amenable to the prosecutions, fines, and other penalties which would attach, in 
due course, to the dealer under the provisions of this Act. 

Sec. id. That any article of food, drug, or Hquor that is adulterated or misbranded 
within the meaning of this Act, and is being transported from one State, Territory, District, 
or insular possession to another for sale, or, having been transported, remains unloaded, 
unsold, or in original unbroken packages, or if it be sold or offered for sale in the District 
of Columbia or the Territories, or insular possessions of the United States, or if it be imported 
from a foreign country for sale, or if it is intended for export to a foreign country, shall be 
liable to be proceeded against in any district court of the United States within the district 
where the same is found, and seized for confiscation by a process of libel for condemnation. 
And if such article is condemned as being adulterated or misbranded, or of a poisonous or 
deleterious character, within the meaning of this Act, the same shall be disposed of by destruc- 
tion or sale, as the said court may direct, and the proceeds thereof, if sold, less the legal 
costs and charges, shall be paid into the Treasury of the United States, but such goods 
shall not be sold in any jurisdiction contrary to the provisions of this Act or the laws of 
that jurisdiction: Provided however, That upon the payment of the costs of such hbel pro- 
ceedings and the execution and delivery of a good and sufficient bond to the effect that such 
articles shall not be sold or otherwise disposed of contrary to the provisions of this Act, 
or the laws of any State, Territory, District, or insular possession, the court may by order 
direct that such articles be delivered to the owner thereof. The proceedings of such libel 



APPENDIX. 1045 

cases shall conform, as near as may be, to the proceedings in admiralty, except that either 
party may demand trial by jury of any issue of fact joined in any such case, and all such 
proceedings shall be at the suit of and in the name of the United States. 

Sec. II. The Secretary of the Treasury shall deliver to the Secretary of Agriculture, 
upon his request from time to time, samples of foods and drugs which are being imported 
into the United States or offered for import, giving notice thereof to the owner or consignee, 
who may appear before the Secretary of Agriculture, and have the right to introduce 
testimony, and if it appear from the examination of such samples that any article of food 
or drug offered to be imported into the United States is adulterated or misbranded within 
the meaning of this Act, or is otherwise dangerous to the health of the people of the United 
States, or is of a kind forbidden entry into, or forbidden to be sold or restricted in sale 
in the country in which it is made or from which it is exported, or is otherwise falsely labeled 
in any respect, the said article shall be refused admission, and the Secretary of the Treasury 
shall refuse delivery to the consignee and shall cause the destruction of any goods refused 
deHvery which shall not be exported by the consignee within three months from the date 
of notice of such refusal under such regulations as the Secretary of the Treasury may pre- 
scribe: Provided, That the Secretary of the Treasury may deliver to the consignee such 
goods pending examination and decision in the matter on execution of a penal bond for the 
amount of the full invoice value of such goods, together with the duty thereon, and on refusal 
to return such goods for any cause to the custody of the Secretary of the. Treasury, when 
demanded, for the purpose of excluding them from the country, or for any other purpose, 
said consignee shall forfeit the full amount of the bond: And provided further, That all 
charges for storage, cartage, and labor on goods which are refused admission or delivery 
shall be paid by the owner or consignee, and in default of such payment shall constitute a 
lien against any future importation made by such owner or consignee. 

Sec. 12. That the term " Territory " as used in this Act shall include the insular pos- 
sessions of the United States. The word " person " as used in this Act shall be construed 
to import both the plural and the singular, as the case demands, and shall include corpora- 
tions, companies, societies and associations. When construing and enforcing the provisions 
of this Act, the act, omission, or failure of any officer, agent, or other person acting for or 
employed by any corporation, company, society, or association, within the scope of his 
employment or office, shall in every case be also deemed to be the act, omission, or failure 
of such corporation, company, society, or association as well as that of the person. 

Sec. 13. That this Act shall be in force and effect from and after the first day of January, 
nineteen hundred and seven. 



THE MEAT-INSPECTION LAW. 

Extract from an act of Congress entitled " An act making appropriations for the 
Department of Agriculture for the fiscal year ending June thirtieth, nine- 
teen HUNDRED AND SEVEN," APPROVED JUNE 30, I906. 

That for the purpose of preventing the use in interstate or foreign commerce, as herein- 
after provided, of meat and meat food products which are unsound, unhealthful, unwhole- 
some, or otherwise unfit for human food, the Secretary of Agriculture, at his discretion, 
may cause to be made, by inspectors appointed for that purpose, an examination and 
inspection of all cattle, sheep, swine, and goats before they shall be allowed to enter into 
any slaughtering, packing, meat-canning, rendering, or similar estabhshment, in which they 
are to be slaughtered and the meat and meat food products thereof are to be used in inter- 
state or foreign commerce; and all cattle, swine, sheep, and goats found on such inspection to 



1046 FOOD INSPECTION AND ANALYSIS. 

show symptoms of disease shall be set apart and slaughtered separately from all other cattle, 
sheep, swine, or goats, and when so slaughtered the carcasses of said cattle, sheep, swine, 
or goats shall be subject to a careful examination and inspection, all as provided by the 
rules and regulations to be prescribed by the Secretary of Agriculture as herein provided for. 

That for the purposes hereinbefore set forth the Secretary of Agriculture shall cause 
to be made by inspectors appointed for that purpose, as hereinafter provided, a post-mortem 
examination and inspection of the carcasses and parts thereof of all cattle, sheep, swine, 
and goats to be prepared for human consumption at any slaughtering, meat-canning, salt- 
ing, packing, rendering, or similar establishment in any State, Territory, or the District 
of Columbia for transportation or sale as articles of interstate or foreign commerce, and 
the carcasses and parts thereof of all such animals found to be sound, healthful, wholesome, 
and fit for human food shall be marked, stamped, tagged, or labeled as " Inspected and 
Passed;" and said inspectors shall label, mark, stamp, or tag as " Inspected and Con- 
demned," all carcasses and parts thereof of animals found to be unsound, unhealthful, 
unwholesome, or otherwise unfit for human food; and all carcasses and parts thereof thus 
inspected and condemned shall be destroyed for food purposes by the said establishment 
in the presence of an inspector, and the Secretary of Agriculture may remove inspectors 
from any such estabUshment which fails to so destroy any such condemned carcass or part 
thereof, and said inspectors, after said first inspection shall, when they deem it necessary, 
reinspect said carcasses or parts thereof to determine whether since the first inspection the 
same have become unsound, unhealthful, unwholesome, or in any way unfit for human 
food, and if any carcass or any part thereof shall, upon examination and inspection subse- 
quent to the first examination and inspection, be found to be unsound, unhealthful, unwhole- 
some, or otherwise ujifit for human food, it shall be destroyed for food purposes by the 
said establishment in the presence of an inspector, and the Secretary of Agriculture may 
remove inspectors ir<^m any establishment which fails to so destroy any such condemned 
carcass or part thereof. 

The foregoing provisions shall apply to all carcasses or parts of carcasses of cattle, 
sheep, swine, and goats, or the meat or meat products thereof which may be brought into 
any slaughtering, meat-canning, salting, packing, rendering, or similar establishment, and 
such examination and inspection shall be had before the said carcasses or parts thereof 
shall be allowed to enter into any department wherein the same are to be treated and pre- 
pared for meat food products; and the foregoing provisions shall also apply to all such 
products which, after having been issued from any slaughtering, meat-canning, salting, 
packing, rendering, or similar establishment, shall be returned to the same or to any similar 
establishment where such inspection is maintained. 

That for the purposes hereinbefore set forth the Secretary of Agriculture shall cause 
to be made by inspectors appointed for that purpose an examination and inspection of 
all meat food products prepared for interstate or foreign commerce in any slaughtering, 
meat-canning, salting, packing, rendering, or similar estabHshment, and for the purposes 
or any examination and inspection said inspectors shall have access at all times, by day 
or night, whether the establishment be operated or not, to every part of said establishment; 
and said inspectors shall mark, stamp, tag, or label as " Inspected and Passed " all such 
products found to be sound, healthful, and wholesome, and which contain no dyes, chemicals, 
preservatives, or ingredients which render such meat or meat food products unsound, 
unhealthful, unwholesome, or unfit for human food; and said inspectors shall label, mark, 
stamp, or tag as " Inspected and Condemned " all such products found unsound, unhealth- 
ful, and unwholesome, or which contain dyes, chemicals, preservatives, or ingredients which 
render such meat or meat food products unsound, unhealthful, unwholesome, or unfit for 
human food, and all such condemned meat food products shall be destroyed for food pur- 



APPENDIX. 1047 

poses, as hereinbefore provided, and the Secretary of Agriculture may remove inspectors 
from any establishment which fails to so destroy such condemned meat food products: 
Provided, That, subject to the rules and regulations of the Secretary of Agriculture, the pro- 
visions hereof in regard to preservatives shall not apply to meat food products for export 
to any foreign country and which are prepared or packed according to the specifications or 
directions of the foreign purchaser, when no substance is used in the preparation or packing 
thereof in conflict with the laws of the foreign country to which said article is to be exported; 
but if said article shall be in fact sold or offered for sale for domestic use or consumption, 
then this proviso shall not exempt said article from the operation of all the other provisions 
of this act. 

That when any meat or meat food product prepared for interstate or foreign com- 
merce which has been inspected as hereinbefore provided and marked " Inspected and 
Passed " shall be placed or packed in any can, pot, tin, canvas, or other receptacle or cover- 
ing in any establishment where inspection under the provisions of this act is maintained, 
the person, firm, or corporation preparing said product shall cause a label to be attached 
to said can, pot, tin, canvas, or other receptacle or covering, under the supervision of an 
inspector, which label shall state that the contents thereof have been " Inspected and 
Passed " under the provisions of this act; and no inspection and examination of meat or 
meat food products deposited or inclosed in cans, tins, pots, canvas, or other receptacle or 
covering in any establishment where inspection under the provisions of this act is maintained 
shall be deemed to be complete until such meat or meat food products have been sealed or 
inclosed in said can, tin, pot, canvas, or other receptacle or covering under the supervision of 
an inspector, and no such meat or meat food products shall be sold or offered for sale by 
any person, firm, or corporation in interstate or foreign commerce under any false or deceptive 
name; but established trade name or names which are usual to such products and which 
are not false and deceptive and which shall be approved by the Secretary of Agriculture are 
permitted. 

The Secretary of Agriculture shall cause to be made, by experts in sanitation or by other 
competent inspectors, such inspection of all slaughtering, meat-canning, salting, packing, 
rendering, or similar establishments in which cattle, sheep, swine, and goats are slaughtered 
and the meat and meat food products thereof are prepared for interstate or foreign commerce 
as may be necessary to inform himself concerning the sanitary conditions of the same, and to 
prescribe the rules and regulations of sanitation under which such establishments shall be 
maintained; and where the sanitary conditions of any such establishment are such that 
the meat or meat food products are rendered unclean, unsound, unhealthful, unwholesome, 
or otherwise unfit for human food, he shall refuse to allow said meat or meat food products 
to be labeled, marked, stamped, or tagged as " Inspected and Passed." 

That the Secretary of Agriculture shall cause an examination and inspection of all cattle, 
sheep, swine, and goats, and the food products thereof, slaughtered and prepared in the 
establishments hereinbefore described for the purposes of interstate or foreign commerce 
to be made during the nighttime as well as during the daytime when the slaughtering of said 
cattle, sheep, swine, and goats, or the preparation of said food products is conducted during 
the nighttime. 

That on and after October first, nineteen hundred and six, no person, firm, or corpora- 
tion shall transport or offer for transportation, and no carrier of interstate or foreign commerce 
shall transport -or receive for transportation from one State or Territory or the District of 
Columbia to any other State or Territory or the District of CoLimbia, or to any place under 
the jurisdiction of the United States, or to any foreign country, any carcasses or parts thereof, 
meat, or meat food products thereof which have not been inspected, examined, and marked 
as " Inspected and Passed," in accordance with the terms of this act and with the rules and 



1048 FOOD INSPECTION AND ANALYSIS. 

regulations prescribed by the Secretary of Agriculture: Provided, That all meat and meat 
food products on hand on October first, nineteen hundred and six, at establishments where 
inspection has not been maintained, or which have been inspected under existing law, shall 
be examined and labeled under such rules and regulations as the Secretary of Agriculture 
shall prescribe, and then shall be allowed to be sold in interstate or foreign commerce. 

That no person, firm, or corporation, or officer, agent, or employee thereof, shall forge, 
counterfeit, simulate, or falsely represent, or shall without proper authority use, fail to use, 
or detach, or shall knowingly or wrongfully alter, deface, or destroy, or fail to deface or 
destroy, any of the marks, stamps, tags, labels, or other identification devices provided for 
in this act, or in and as directed by the rules and regulations prescribed hereunder by the 
Secretary of Agriculture, on any carcasses, parts of carcasses, or the food product, or containers 
thereof, subject to the provisions of this act, or any certificate in relation thereto, authorized 
or required by this act or by the said rules and regulations of the Secretary of Agriculture, 

That the Secretary of Agriculture shall cause to be made a careful inspection of all 
cattle, sheep, swine, and goats intended and offered for export to foreign countries at 
such times and places, and in such manner as he may deem proper, to ascertain whether 
such cattle, sheep, swine, and goats are free from disease. 

And for this purpose he may appoint inspectors who shall be authorized to give an 
official certificate clearly stating the condition in which such cattle, sheep, swine, and goats 
are found. 

And no clearance shall be given to any vessel having on board cattle, sheep, swine, or 
goats for export to a foreign country until the owner or shipper of such cattle, sheep, swine, 
or goats has a certificate from the inspector herein authorized to be appointed, stating that 
the said cattle, sheep, swine, or goats are sound and healthy, or unless the Secretary of 
Agriculture shall have waived the requirement of such certificate for export to the particular 
country to which such cattle, sheep, swine, or goats are to be exported. 

That the Secretary of Agriculture shall also cause to be made a careful inspection of the 
carcasses and parts thereof of all cattle, sheep, swine, and goats, the meat of which, fresh, 
salted, canned, corned, packed, cured, or otherwise prepared, is intended and offered for 
export to any foreign country, at such times and places and in such manner as he may deem 
proper. 

And for this purpose he may appoint inspectors who shall be authorized to give an official 
certificate stating the condition in which said cattle, sheep, swine, or goats, and the meat 
thereof, are found. 

And no clearance shall be given to any vessel having on board any fresh, salted, canned, 
corned, or packed beef, mutton, pork, or goat meat, being the meat of animals killed after 
the passage of this act, or except as hereinbefore provided for export to and sale in a foreign 
country from any port in the United States, until the owner or shipper thereof shall obtain 
from an inspector appointed under the provisions of this act a certificate that the said cattle, 
sheep, swine, and goats were sound and healthy at the time of inspection, and that their 
meat is sound and wholesome, unless the Secretary of Agriculture shall have waived the 
requirements of such certificate for the country to which said cattle, sheep, swine and goats or 
meats are to be exported. 

That the inspectors provided for herein shall be authorized to give official certificates 
of the sound and wholesome condition of the cattle, sheep, swine, and goats, their carcasses 
and products as herein described, and one copy of every certificate granted under the pro- 
visions of this act shall be filed in the Department of Agriculture, another copy shall be 
delivered to the owner or shipper, and when the cattle, sheep, swine, and goats or their 
carcasses and products are sent abroad, a third copy shall be dehvered to the chief ofl&cer 
of the vessel on which the shipment shall be made. 



APPENDIX. 1049 

That no person, firm, or corporation engaged in the interstate commerce of meat or meat 
food products shall transport or offer for transportation, sell or offer to sell any such meat 
or meat food products in any State or Territory or in the District of Columbia or any place 
under the jurisdiction of the United States, other than in the State or Territory or in the 
District of Columbia or any place under the jurisdiction of the United States in which the 
slaughtering, packing, canning, rendering, or other similar establishment owned, leased, 
operated by said firm, person, or corporation is located unless and until said person, firm, 
or corporation shall have complied with all of the provisions of this act. 

That any person,, firm, or corporation, or any officer or agent of any such person, firm, 
or corporation, who shall violate any of the provisions of this act shall be deemed guilty 
of a misdemeanor, and shall be punished on conviction thereof by a fine of not exceeding 
ten thousand dollars or imprisonment for a period not more than two years, or by both 
such fine and imprisonment, in the discretion of the court. 

That the Secretary of Agriculture shall appoint from time to time inspectors to make 
examination and inspection of all cattle, sheep, swine, and goats, the inspection of which is 
hereby provided for, and of all carcasses and parts thereof, and of all meats and meat food 
products thereof, and of the sanitary conditions of all establishments in which such meat 
and meat food products hereinbefore described are prepared; and said inspectors shall 
refuse to stamp, mark, tag, or label any carcass or any part thereof, or meat food product 
therefrom, prepared in any establishment hereinbefore mentioned, until the same shall 
have actually been inspected and found to be sound, healthful, wholesome, and fit for human 
food, and to contain no dyes, chemicals, preservatives, or ingredients which render such 
meat food product unsound, unhealthful, unwholesome, or unfit for human food; and to 
have been prepared under proper sanitary conditions, hereinbefore provided for; and shall 
perform such other duties as are provided by this act and by the rules and regulations to be 
prescribed by said Secretary of Agriculture; and said Secretary of Agriculture shall, from 
time to time, make such rules and regulations as are necessary for the efficient execution of 
the provisions of this act, and all inspections and examinations made under this act shall 
be such and made in such manner as described in the rules and regulations prescribed by 
said Secretary of Agriculture not inconsistent with the provisions of this act. 

That any person, firm, or corporation, or any agent or employee of any person, firm, 
or corporation, who shall give, pay, or offer, directly or indirectly, to any inspector, deputy 
inspector, chief inspector, or any other officer or employee of the United States authorized 
to perform any of the duties prescribed by this act or by the rules and regulations of the 
Secretary of Agriculture any money or other thing of value, with intent to influence said 
inspector, deputy inspector, chief inspector, or other officer or employee of the United States 
in the discharge of any duty herein provided for, shall be deemed guilty of a felony and, upon 
conviction thereof, shall be punished by a fine not less than five thousand dollars nor more 
than ten thousand dollars and by imprisonment not less than one year nor more than three 
years; and any inspector, deputy inspector, chief inspector, or other officer or employee of 
the United States authorized to perform any of the duties prescribed by this act who shall 
accept any money, gift, or other thing of value from any person, firm, or corporation, or 
officers, agents, or employees thereof, given with intent to influence his official action, or who 
shall receive or accept from any person, firm, or corporation engaged in interstate or foreign 
commerce any gift, money, or other thing of value given with any purpose or intent what- 
soever, shall be deemed guilty of a felony and shall, upon conviction thereof, be summarily 
discharged from office and shall be punished by a fine not less than one thousand dollars nor 
more than ten thousand dollars and by imprisonment not less than one year nor more than 
three years. 

That the provisions of this act requiring inspection to be made by the Secretary of 



1050 FOOD INSPECTION AND ANALYSIS. 

Agriculture shall not apply to animals slaughtered by any farmer on the farm and sold and 
transported as interstate or foreign commerce, nor to retail butchers and retail dealers in 
meat and meat food products, supplying their customers: Provided, That if any person shall 
sell or offer for sale or transportation for interstate or foreign commerce any meat or meat 
food products which are diseased, unsound, unhealthful, unwholesome, or otherwise unfit 
for human food, knowing that such meat food products are intended for human consump- 
tion, he shall be guilty of a misdemeanor, and on conviction thereof shall be punished by a 
fine not exceeding one thousand dollars or by imprisonment for a period of not exceeding 
one year, or by both such fine and imprisonment: Provided also, That the Secretary of Agri- 
culture is authorized to maintain the inspection in this act provided for at any slaughtering, 
meat canning, salting, packing, rendering, or similar establishment notwithstanding this 
exception, and that the persons operating the same may be retail butchers and retail dealers 
or farmers; and where the Secretary of Agriculture shall establish such inspection then 
the provisions of this act shall apply notwithstanding this exception. 

That there is permanently appropriated, out of any money in the Treasury not other- 
wise appropriated, the sum of three million dollars, for the expenses of the inspection of 
cattle, sheep, swine, and goats and the meat and meat food products thereof which enter 
into interstate or foreign commerce and for all expenses necessary to carry into effect the 
provisions of this act relating to meat inspection, including rent and the employment of labor 
in Washington and elsewhere, for each year. And the Secretary of Agriculture shall, in his 
annual estimates made to Congress, submit a statement in detail, showing the number of 
persons employed in such inspections and the salary or per diem paid to each, together with 
the contingent expenses of such inspectors and where they have been and are employed. 



INDEX. 



Abbe construction, 95 

influence of temperature, 96 
manipulation, 95 
refractometer, 86, 94 
Abrastol, 903 
Absinthe, 787 
Acetanilide in vanilla extract, 918 

tests for, 925, 926 
Acetic acid, 38, 788 
Acetyl value, 514 
Achroodextrine, 598 

Acid fuchsin, 815, 831, 837, 838, 845, 851, 
854, 868 
test for, 845 
green, 826 

magenta, see Acid fuchsin 
violet N, 856, 873 
yellow G, 815, 837, 847, 854, 868 
Acidity determination by hydrogen elec- 
trode, 102 1 
apparatus for, 1025 
calomel electrode for, 1028 
electrical instruments for, 1029 
hydrogen electrode, 1027 
principle of method, 1022 
theory of method, 1024 
titration, 1030 

of coffee, 1035 
fruit juices, 1037 
milk, 1033 
tea, 1035 

typical curves, 1030 
Acidity determination by standard solutions, 

24-27 
Acids, fatty, 497, 501, 518, 529 
of acetic series, 486 

clupanodonic series, 487 
linolenic series, 487 
linolic series, 487 
oleic series, 487 



Acids, mineral, in vinegar, 797 

organic, 38, 982, 983, 1008, 1009 
Ackermann and Steinmann table for alcohol 

from refraction, 748 
Ackermann table for extract from refraction, 

755 
Adams fat method, 122 
Adenine, 35, 205 
" Aerated " butter, 563 
Agar agar, in jelly, 991, 1002 
Aging of liquors, 764, 765 
Alanine, 35 
Alantoin, 308 

Albrech lemon color method, 936 
Albumin, acid, S3 
alkali, $$ 
egg, 270 

meat extract, 246, 247, 248, 249 
determination, 254 
milk, no 

determination, 133 
muscle, 205, 206 

determination, 229 
Albuminoids, 31 
Albumins, 30, 306 
Albumose, ^;i, 254 
Alcannin, 852 
Alcohol, detection, 686 

determination, 687 

by distillation, 681, 687 
ebuUioscope, 704 
evaporation, 689 
from refraction, 747 

specific gravity, 688 
extract of spices, 424 
in malt liquors, 747 
methyl, 781, 935 
preparation of, 763 
stills, 688 
tables, 690, 748 
1051 






1052 



INDEX. 



Alcoholic beverages, 682. See also Liquors. 

fermentation, 682 
Aldehydes, determination, 777 
Aldoses, 36 
Ale, 740, 741, 743, 745. See also Beer. 

ginger, 1012 
Aleurone, 77 

Alizarin, 815, 832, 856, 872 
blue, 857, 873 
red, 855, 871 
Alkaloids, 29, 35, 759 
Alkanna tincture, 79 
AUantoin, 308 

AUen-Marquardt fusel oil method, 779 
Allihn sugar method, 632 

table, 633, 634 
Allspice, 434 

adulteration, 438 

composition of, 434 

methods of analysis. See Spices and 

Cloves, 
microscopj^, 436 
standard, 438 
tannin in, 435 
Almond extract, 942 

adulteration of, 943 
alcohol in, 943, 946 
benzaldehyde in, 942, 944, 

945 
hydrocyanic acid in, 942, 

946 
methods of analysis, 945 
alcohol, 946 
benzaldehyde, 944, 945 
hydrocyanic acid, 946 
nitrobenzol, 945 
nitrobenzol in, 943, 945 
standards, 943 
meal, 375 
Almonds, bitter, oil of, 942 

composition of, 284 
Alum in baking powder, 350, 351, 352, 360 
bread, 342 
flour, 324, 334 
pickles, 986 
wine, 725 
Alumina, determination of, 312, 361 
Aluminum salts in baking powder, 350, 351 

cream of tartar, 348 
Amagat and Jean refractometer, 86 



Amandin, 31 

Amaranth, 815, 834, 837, 851, 854, 868 

Amides, 29, 34, 308 

Amines, 29 

Amino acids, 29, 35 

determination, 63 
compounds in milk, no 
determination, 133 
Ammonia, determination, 62 

in baking powder, 349, 350, 362 
foods, 29, 35 
milk, 133 
Ammonium fluoride, 901 
Amthor caramel test, 784 
Amygdalin, 35 
Amylodextrin, 598 
Amyloid, 78, 79 
Analyst, functions of, 3, 4 
Angostura, 786, 787 
Anilin orange, 160, 162 
yellow, 858, 87s 
Animal diastase, 293 
Anise extract, standards, 949 

oil, standards, 950 
Anisette, 787 
Annatto, 815, 819, 823, 849 

in butter, 557, 558, 559 
milk, 161, 162 
Antiseptic. See Preservatives. 
Apiose, 36 
Apparatus, 18 
Apple butter, 986 

essence, imitation, 955 
juice, 707, 709 
pulp, detection, 1002 
Apples, composition of, 283, 284, 993 
Apricots, composition of, 283 
Araban, 38, 294 
Arabinose, 36, 294 
Arachidic acid, 29, 487 
Arata color test, 841 
Archil, 815, 819, 822 
Army rations, 265 
Arnold peroxide test, 173 

and Mentzel formaldehyde test, 881 
Arrowroot starch, 291 
Arsenic compounds in colors, 813, 815 
detection and determination, 63 
in baking chemicals, 351 
beer, 746, 760 



INDEX. 



1053 



Arsenic in confectionery, 68 1 
glucose, 663 
vinegar, 811 
Johnson-Chittenden-Gautier meth- 
od, 63 
Marsh apparatus, 64 
Sanger-Black-Gutzeit test for, 65 
Artificial colors, 812 

fruit essence, 954, 955 
sweeteners, 905 
Asaprol, 903 

Asbestos fiber, preparation of, 618, 622 
Ash analysis, scheme for, 311 
determination of, 51 
of food, 38 
Asparagin, 35, 308 
Asparagus, composition of, 282 
Auramin G, 848, 857, 874 

0,831,848,857,874 
Aurantia, 856, 872 
Aurin, 832 

Azo blue, 815, 829, 837, 846, 855, 870 
Azoacidrubine, 826 
Azocarmine B, 854, 869 
G, 854, 869 
Azoflavin, 856, 872 
Azofuchsine G, 854, 869 
Azolitmin, 819, 822, 855, 870 
Azorubin, 815, 837, 851, 855, 870 



Babcock asbestos milk fat method, 121 

solids method, 121 
centrifugal fat method, 123 
solids not fat formula, 140 
Bacon formic acid method, 899, 901 

and Dunbar citric acid method, 982 
lactic acid method, 983 
Baier and Neumann sucrose test, 189 
Baker tin method, 972, 975 
Baking powder, 349 

adulteration of, 351 
alum, 350, 352 
cathartics, 352 
classification, 349 
controversies, 351 
methods of analysis, 352 
alumina, 361 
ammonia, 362 
arsenic, 362 



Baking powder, methods of analysis, 352 

carbon dioxide, avail- 
able, 355 
residual, 355 
total, 353 
lead, 362 
lime, 361 

phosphoric acid, 362 
potash, 361 
soda, 361 
starch, 360 
sulphuric acid, 362 
tartaric acid, 356 
phosphate, 349 
tartrate, 349 
Balances, 19 
Bamihl gluten test, 336 
Banana essence, artificial, 955 
Bananas, composition of, 283 
Barbier and Jandrier formaldehyde test, 882 
Barium compounds in colors, 784 
Bark as an adulterant, 442 
Barley, 280, 281 
ash, 310 

microscopy of, 317 
proteins, 309 
starch, 290 
Barwood, 819, 822, 852 
Basic colors, 841 
Bast fibers, 76 

Baudouin sesame oil test, 538 
Beading oil, 770 
Bean starch, 291 
Beans, 281, 282 

in coffee, 400 
Bechi cottonseed oil test, 536 
Beckmann freezing-point apparatus, 49 

test for glucose in honey, 673 
Beechnuts, composition of, 284 
Beef, composition of, 208 
cuts of, 208 

stearin, microscopy of, 582 
tallow, 550 
Beer, 738 

adulteration of, 742 
aloes in, 742, 760 
arsenic in, 746, 760 
ash in, 745 
birch, 1013 
bock-, 740 



1054 



INDEX. 



Beer, brewers' sugar in, 741 
brewing of, 739 
chiretta in, 742, 760 
composition of, 740, 743 
degree of fermentation of, 756 
gentian bitter in 742, 760 
lager, 739 
malt, 744 

substitute, 744 
methods of analysis, 747 
acidity, 757 
alcohol, 747 
arsenic, 760 
ash, 747 

bitter principles, 759 
carbon dioxide, 758 
degree of fermentation, 756 
dextrin, 756 
extract, 747 
glycerol, 756 
phosphoric acid, 757 
preservatives, 761 
protein, 757 
specific gravity, 747 
sugars, 756 
phosphoric acid in, 745 
preservatives in, 746, 761 
proteins in, 745 
quassiin in, 742, 759 
root, 1013 
schenk-, 739 
standards, 742 
temperance-, 746 
uno-, 746 
varieties of, 739 
weiss-, 740 
wort, 739 

gravity of, 754 
Beeswax, 675 

refractometer reading of. 675 
specific gravity of, 675 
Beet sugar, 590 
Beets, composition of, 273 
Behenic acid, 29, 487 

Belfield-Gladding microscopic tallow test, 582 
Bellier acid fuchsin test, 845 
dulcin test, 908 
peanut oil test, 544 
Benches, 13 
Benedictine, 786, 787 



Benzaldehyde, 942, 943, 988 
artificial, 943 
in almond extract, 943 
maraschino cherries, 988 
Benzeneazo-^-naphthylamin, 858, 875 
Benzoic acid, 890 

detection of, 891 
determination, 893 
in butter, 562 

milk, 167 
toxicity of, 891 
Benzopurpurin 4B, 850, 857, 873 
Betaine, 35, 308 
Beta-naphthol, 903 
Beverages, carbonated. See Carbonated 

beverages. 
Biebrich brilliant crocein scarlet. See Bril- 
liant crocein. 
scarlet, 815 
Birch beer, 1013 

Birotation, 608, 666, 667, 668, 671 
Biscuit, gluten, 375 

soja bean, 375 
Bishop arsenic apparatus, 65 
Bismarck brown, 815, 829, 851, 874 

R, 815, 857, 874 
Bisulphites as preservatives, 896 
Bitter almonds, oil of, 942, 943 
Biuret reaction, 34 
Blackberries, composition of, 283 
Blank and Finkenbeiner formaldehyde meth- 
od, 880 
Blarez fluorides test, 902 
Blast pump, 18 
" Blown " cans, 960 
Blue colors, 815, 846 
Blythe cocoa red method, 416 
Bock-beer, 740 
" Boiled " butter, 563 
Bomb calorimeter, 38 
Bombay mace, 483, 484, 485 
Bomer phytosterol acetate test, 525 

sterol method, 522 

Borax, 883. See also Boric acid. 

Bordeaux B, 65, 829, 837, 851, 855, 870 

BX, 856, 871 

G, 855, 870 

Boric acid, 883 

detection, 166, 170, 885 
determination, 884, 886 



INDEX. 



1055 



Boric acid, in butter, 560 

meat, 216, 238 
milk, 166, 170 
Bornstein saccharin test, 907 
Bouillon cubes, 250 

composition, 251 
standards, 250 
Bourbon whiskey, 766, 768, 769 
Bovie electrical apparatus, 1029 
Boyles lemon oil methods, 932 
t^ Bran, wheat, 320 
Brandy, 771 

adulteration of, 773 
composition of, 772 
" drops," 681 
methods of analysis, 777 
new, 772 
potable, 772 
standards, 772 
Brazil nuts, composition of, 284 
wood, 819, 822, 852 
,^ Bread, 338 

acidity of, 340 
alum in, 342 
composition of, 339, 340 
copper sulphate in, 342 
fat in, 341 

methods of analysis, 343 
water in, 340 
wrapping of, 342 
yeast food for, 341 
w- Breakfast cereals, 369 
Brewing, 739 
Brick cheese, 197 
Brie cheese, 197 
Brilliant crocein, 837, 851 
yellow, 855, 871 

S, 848, 854, 868 
Bromination oil test, 511 
Bromine absorption of oils, 509 
Brown and Duvel moisture method, 285 
Brown colors, 815 
sugar, 589 
Browne dextrin method, 672 

invert sugar test, 674 
Buckthorn, 819, 823, 848 
Buckwheat, ash of, 310 

composition of, 280, 281 
flour, 323 
microscopy of, 319 



Buckwheat, starch, 290 
Burgundy wine, 714, 715, 717 
Butter, SSI 

adulteration of, 556 

annatto in, S58 

apple, 986 

azo colors in, SS7, 558, 559 

benzoic acid in, 560, s62 

boric acid in, 560 

carrotin in, S57 

coal-tar dyes in, SS7, 558, 559 

coloring in, SS7 

composition of, 551 

curd of, examination, 574 

distinction from oleomargarine and 

process butter, 571 
effects of feeding, 552 
fat, composition of, 551 

constants, 528, 529 

standard, S56 
filled, 563 
fruit, 986 
glucose in, S62 
methods of analysis, 552 

ash, 556 

casein, 555 

colors, 557 

fat, ^'-.i 

foam test, 572 

lactic acid, 556 

lactose, 556 

preservatives, 560 

process butter, detection, 571- 
576 

salt, 556 

sampUng, 552, 553 

water, 553 

Waterhouse test, 573 
microscopic examination of, 574 
milk test, 573 
nut, 576 

Polenske number of, 571 
preservatives in, 560 
refraction of, 568 
renovated, 563, 571 
salicylic acid in, 560, 561 
standards, 556 
turmeric in, 557 
water in, 553, 563 
Waterhouse test, 573 



1056 



INDEX. 



Butter yellow, 849, 858, 875 
Butterine, 563 

oil, 542 
Butyric acid, 29, 486 
Butyro-refractometer, 86, 87 
critical line of, 92 
limits of butter readings, 569 
manipulation, 88 
oil readings on, 493, 494, 495 
olive and cottonseed oil read- 
ings, 533 
sliding scale for, 93 
special thermometer for, 570 
table of equivalent refractive in- 
dices, 91, 92 
temperature variation of read- 
ing, 93 
testing scale, 90 

Cabbage, composition of, 282 
Caffeine, 35, 385 

in carbonated beverages, 1014, 
1017, 1019 
determination of, 1017, 1019 
cocoa, 409 

determination of, 413 
coffee, 393, 394 

determination of, 397 
tea, 380 
determination of, 386 
Caffeol, 392 
Caffetannic acid, 392 

determination of, 395 
Cake, 338, 342 

Calcium carbonate crystals, 77 
oxalate crystals, 77 
sucrate, 187 
detection of, 189 
California wines, 718 
Calorie, 38, 40 
Calorimeter, bomb, 38 
oil, 512 
respiration, 39 
Camembert cheese, 197 
Camera, micro, 83 
Canada balsam, 73 
Candy, see Confectionery. 

standard, 677 
Cane sugar, 587 

composition of, 589 



Cane sugar, detection of, 608 

in cream, 189 
milk, 189 
determination of, 

by copper reduction, 642 
polarimetry, 610, 656 
in cereals, 304 

condensed milk, 182 
inversion of, 611, 612 
manufacture of, 588, 590 
methods of analysis, 608 
ash, 609 

invert sugar, 613 
moisture, 609 
organic non-sugars, 609 
quotient of purity, 610 
sucrose, 610 
ultramarine, 613 
refining, 591 
standard, 587 
test for, 608 
Canned food, 957 

composition of, 959 
decomposition of, 960 
metallic impurities in, 961 
method of canning, 957 
methods of analysis, 970 
preservatives in, 969 
fruits, 957 
meats, 218, 219 
vegetables, 957 
Cans, detection of spoiled, 960, 970 

gases from spoiled, 960, 970 
Capers, 985 
Capric acid, 29, 486 
Caproic acid, 29, 486 
Caprylic acid, 29, 486 
Capsaicin, 454 
Capsicums, 453, 458 
Caramel, 815, 821 

in distilled liquors, 765, 770, 771 
milk, 161, 169 
vanilla extract, 917, 926 
vinegar, 810 
Carbohydrates, 35, 36, 586-600 
classification, 36 
of cereals, 288, 304 
eggs, 272 
Carbon dioxide determination in baking 
chemicals, 353, 355 



•>'^l». 



INDEX. 



1057 



Carbon dioxide determination in beer, 758 

yeast, 347 
Carbonated beverages, loii 

acids in, 1013 
bottled, 1012 
caffein in, 1014, 1017, 

1019 
cocaine in, 1014, 

1018, 1019 
colors in, 1014 
foam producers in 

1014 
habit-forming drugs 

in, 1014 
methods of analysis, 
1014 
caffeine, 1017, 

1019 
cocaine, 1018, 

1019 
glycerol, 1019 
phosphoric acid, 

1015 
saponin, 1015 
preservatives in, 1013 
saponin in, 1014,1015 
sweeteners in, 1013 
syrups for, 1012 
Carminaph garnet, 858, 875 
Carnitine, 35, 205, 243 
Carnosine, 205, 243 
Carotin in butter, 557 
Carrot, composition of, 282 
Carthamin. See SaflSower. 
Casein, 32, 109, in 

determination in milk, 132 
Caseose, 2,3 

determination in cheese, 201 
in milk, 133 
Casoid flour, 375 
Cassia, 438 

adulteration of, 442 

buds, 439 

composition of, 439 

extract, 950, 951 

methods of analysis. See Spices. 

microscopy of, 440 

oil, 439, 950 

standards, 950 
standard, 442 



Catsup. See Ketchup. 
Cauliflower, composition of, 282 
Caviar, 261 
Cayenne, 453 

adulteration of, 460 
composition of, 454-458 
methods of analysis, 461. See also 
Spices, 
colors, 461 
microscopy of, 458 
mineral adulterants in, 460 
oil cf, 454 
redwood in, 460 
standard, 460 
Cazeneuve color scheme, 736, 737 
Celery, composition of, 282 

seed extract, standards, 950 
oil, standards, 950 
Cellulose, 38, 294 
Centrifuge, milk-fat, 123 
universal, 20 
Cereal breakfast foods, 369 
composition, 371 
products, microscopy of, 314 
Cereals, 280 

ash of, 310 
carbohydrates of, 288 

separation Oi, 304 
composition of, 280, 281 
methods of analysis, 285 
ash, 286 

crude fiber, 286, 305 
dextrin, 304 
ether extract, 286 
hemiceliulose, 305 
nitrogen-free extract, 287 
pentosans, 294, 305 
preparation of sample, 285 
protein, 286 
starch, 292, 304 
sugar, 293, 304 
water, 285 
proteins of, 305 
sulphuring of, 287 
Chace pinene method, 941 

total aldehyde method, 933 
Champagne, 714, 717 
Chaptalizing, 721 
Charcoal, determination of, 312 
Charlock, 469, 476, 477 



11 



1058 



INDEX. 



Charlock, detection, 477 
oil, 540 

constants, 528, 529, 540 
Chartreuse, 786, 787 
Cheddar cheese, 197 
Cheese, 196 

adulteration of, 198 
composition of, 196, 197 
cream, 199 
filled, 199 

methods of analysis, 199 
acidity, 202 
amino acids, 201 
ammonia, 201 
ash, 202 
caseoses, 201 
fat, 199 

foreign, 202 
lactose, 202 
paracasein lactate, 202 
paranuclein, 201 
peptones, 201 
protein, coagulable, 201 

total, 200 
salt, 202 
water, 199 

water-soluble nitrogen, 201 
sampling, 199 

skimmed milk, 198, 199, 203 
standards, 198 
varieties of, 197 
whole milk, 199 
Cherries, composition of, 283 

maraschino, 988 
Cherry soda, 1013 
Cheshire cheese, 197 
Chestnuts, composition of, 284 
Chicago blue 6 B, 869 
Chicory, 395, 398, 400, 401, 402, 403 
Chili sauce, 977 
Chiretta, 742, 760 
Chlor iodide of zinc, 78 
Chloral hydrate, 80 

test for charlock, 477 
Chlorine in vegetable substances, 313 
Chlorogenic acid, 392 
Chocolate. See Cocoa, 
milk, 410 

composition of, 411 



Chocolate, milk, sucrose and lactose determi- 
nation in, 415 

Cholesterol, 486 

crystallization of, 522 
determination of, 521 
distinction from phytosterol, 521 
separation of, 522 

Cholin, 35, 308 

Chromate of lead, 678, 681 

Chromogenic bacteria, 117 

Chromotrope 2 R, 854, 869 

Chrysamin G, 829, 847, 856, 872 
R, 829, 847, 856, 872 

Chrysoidin, 848, 857, 874 

R, 857, 874 
Chrysophenin, 856, 871 
Cibrola, 204 
Cider, 707 

adulteration of, 711 
ash of, 711 
composition of, 709 
fermented, 709, 710 
malic acid in, 712 
manufactuie of, 707 
methods of, analysis. See Wine. 
sweet, 1006 

vinegar, 788, 790. See also Vinegar, 
watering of, 711 
yeast in, 707 
Cieddu, 174 
Cinnamon, 438 

adulteration of, 442 
composition of, 439, 440 
extract, 950, 951, 952 
methods of analysis. See Spices, 
microscopy of, 440 
oil, standards, 950 
standard, 442 
Citral, 928, 929, 938 

determination, 934, 940 
in carbonated beverages, 1015 
Citric acid, 38 

in fruit products, 979, 982, 1009, 
1013 
ketchup, 979, 982 
milk, no, in 
Citronella oil, 938, 939 
Citronellal, 939 
Citronin, 826 
Clams, 262 



INDEX. 



1059 



Claret wine, 714, 715, 717 
Clarifying reagents in microscopy, 79 

sugar analysis, 610,644 
Clerget formula, 611 
Cloth red B, 855, 871 
Clove extract, 950, 951, 952 

oil, 950 
Cloves, 426 

adulteration of, 432 
cocoanut shells in, 433 
composition of, 428 
exhausted, 432 

methods of analysis, 422, 429. See 
also Spices, 
tannin, 429 
microscopy of, 430 
oil of, 426, 950 
standard, 432 
stems, 432 
tannin in, 429 
Clupanodonic acid, 29, 487 
Clupein, 32 

Coal-tar colors. See Colors, coal-tar. 
Cocaine, detection of, 1018, 1019 

in carbonated beverages, 1014 
Cochineal, 815, 819, 822, 824, 855, 869 

in sausages, 240 
Cocoa, 406 

adulteration of, 417 
alkali in, 418 
ash of, 408 

butter, 411, 428, 429, 550 
colors in, 421 

composition of, 407, 408, 409 
compounds, 410 
fat, foreign, in, 420 
manufacture of, 407 
methods of, analysis, 411 
ash, 411 
caffeine, 413 
casein, 412 
cocoa-red, 416 
crude fiber, 414 
lactose, 415 
pentosans, 415 
protein, 412 
starch, 414, 415 
sucrose, 415 
theobromine, 413 
water, 411 



Cocoa, microscopy of, 418 
nibs, 407, 408, 409 
nitrogeneous bodies in, 410 
pentosans in, 410 
shells, 408, 409, 420 
standards, 417 
starch, foreign, in, 420 
sugar in, 420 
theobromine in, 410 
Cocoanut, composition of, 284 
oil, 549 

composition of, 549 
constants, 528, 529 
pulp, 549 
shells, 433, 434 
Coffalic acid, 392 
Coffearine, 392 
Coffee, 392 

acidity, 1035 
adulteration of, 395, 397 
ash of, 392, 393, 394 
caffeine free, 404 

in, 392, 393, 394 
caffeol in, 392 
caffetannic acid in, 392 
cellulose in, 392, 393 
chicory in, 400, 402 | 
chlcrogenic acid in, 392 
coffaUc acid in, 392 
coffearine in, 392 
coloring of, 398 
composition of, 393, 394 
constituents of, 392 
date stones in, 403 
dextrins in, 392 
glazing of, 398 
hygienic, 404 
methods of analysis, 395 
acidity, 1035 
ash, 39S 
caffeine, 397 
caffetannic acid, 395 
crude fiber, 395 
ether extract, 395 
proteins, 395 
starch, 395 
sucrose, 395 
sugars, reducing, 395 
10 per cent extract, 395, 403 
water, 395 



lUbU 



INDEX. 



Cofifee, microscopy of, 399 

oil in, 392 

'pellets," 398 

pentosans in, 392 

protein in, 392 

pyridine in, 392 

standards for, 397 

substitutes, 395 

sugar in, 393, 394 

tannin free, 405 

vacuum packed, 405 
Cognac, 771. See also Brandy. 

oil, 773 
Collagen, 31, 205 

determination of, 228 
Colorimeter, Schreiner, 66 
Colorimetric analysis, 66 
Colors, 812 

acid, 841 

test for, 844 
allowed, 825 

identification, 833 
separation, 833 
animal, 817 

detection, 818 
dyeing test, 818 
extraction by immiscible sol- 
vents, 818 
reactions in solution, 820, 

822, 823 
reactions on fiber, 818, 819 
special tests, 821 
arsenic compounds, 815 
barium compounds, 815 
basic, 841 
blue, 815, 846 
brown, 815 
coal tar, 824 

detection and identification 
in foods, 840 
acetic ether extraction, 

844 
acid dyes, 841 
amyl alcohol extraction, 

843 
Arata dyeing method, 

841 
basic dyes, 841 
bromide test, 864 
cyanide test, 866 



Colors, coal tar, direct identification, 853 
ether separation, 844 
extraction, 840, 843 
identification, 841, 853, 859 
Loomis' scheme, 845 
Mathewson method of sep- 
aration by immiscible 
solvents and identifica- 
tion, 859 
Mathewson table of reac- 
tions of dry colors or 
dyed fibers, 853 
nitrous acid test, 865 
reduction and reoxidation, 

866 
Robin test, 844 
separation, 840, 859 
separation from dried food, 

844 
Sostegni and Carpentieri 

dyeing method, 842 
examination of, 826 

Mathewson quantita- 
tive separation meth- 
od, 836 
Price-Estes method for 
allowed colors, 833, 
834 
Price-IngersoU method 
for allowed colors, 

833 
Rota scheme for, 827 
schemes for, 827 
spectroscopic methods, 

840 
ultimate analysis, 839 
copper compounds, 815 
extraction of, by immiscible solvents, 

818, 836, 843, 844, 859 
green, 815, 846 
harmless, 815 
in butter, 557 

carbonated beverages, 1014 
cayenne, 461 
confectionery, 677, 681 
jams and Jellies, 990 
ketchup, 980, 981 
milk, 159, 160 
mustard, 476, 478 
in sugar, 613 



INDEX. 



1061 



Colors, injurious, 814, 815 
lakes, 817 

lead compounds, 815, 816 
mercury compounds, 815 
mineral, 815 

detection of, 816 
mordants for, 818 
non-injurious, 814, 815 
orange, 815, 847 
red, 815, 849 
Rota scheme for, 827 
separation by solvents, 818, 836, 843, 

844, 859 
toxic effect of, 813 
vegetable, 817 

detection of, 818 
dyeing tests for, 818 
extracticn by immiscible sol- 
vents, 8i8 
reactions in solution, 820, 822, 

823 
reactions on fiber, 818, 819 
special tests, 821 
violet, 815, 846 
wool dyeing, 818, 841, 842 
yellow, 815, 847 
Colostrum, 114 

Commercial glucose. See Glucose. 
Compressed j^east, 344 
Conalbumin, 270 
Concentrated foods, 265 
Condensed milk, 195 

as a milk adulterant, 171 
composition of, 176, 177 
methods of analysis, 178 
cane sugar, 182 
fat, 179, 180 
foreign, 183 
in original milk, 

183 
lactose, 181 
protein, 181 
total solids, 178 
standards for, 176 
Confectionery, 677 

adulteration of, 677, 681 
arsenic in, 677 
colors in, 677, 681 
glucose in, 677 
lead chromate in, 677 



Confectionery, methods of analysis, 678 
alcohol, 681 
arsenic, 68i 
ash, 678 
colors, 681 
ether extract, 679 
lead chromate, 678 
mineral adulterants, 678 
paraffin, 679 
polarization, 680 
solids, 678 
starch, 680 
mineral adulterants, 677 
Congo red, 815, 829, 837, 857, 873 
Connective tissue, 205 
Copper reduction. See Fehling process, 
salts, 967 

determination of, 973, 977 
in vinegar. 804, 811 
Copra oil, 549 
Cordials, 786 

analysis of, 787 
composition of, 787 
Corky tissue, 76 
Corn, 280, 281 

ash of, 310 

bleaching of canned, 969 

composition of, 280, 281 

flakes, 371 

meal, 337 

acidity determination in, 338 
composition of, 338 
manufacture of, 337 
spoilage of, 338 
microscopy of, 317 
oil, 541 

constants, 528, 529 
proteins of, 309 
puffs, 371 
starch, 290 
syrup, 5q8 
Cornelison butter color test, 559 
Corning of meat, 215 
Cotton cane sugar method, 171 
Cotton scarlet 3 B, see Brilliant crocein. 
Cottonseed, 535 

oil, 535 

composition of, 535 
constants, 528, 529, 530 
hydrogenated, 536 



1062 



INDEX. 



Cottonseed, oil, methods of analysis, 536, 
537. See also Oils. 

Bechi test, 536 
Halphen test, 537 
preparation of, 535 
standards, 536 
stearin, 536 
tests for, 536, 537 
Coumarin, qiy 

detection, 923 
determination, 920 
microscopical structure, 924 
Crampton and Simon caramel test, 784 

palm oil tests, 565 
Cranberries, composition of, 283 
Cream, 186 

adulteration of, 186 
cheese, 199 
evaporated, 186 
foreign fats in, 186 
gelatin in, 186 
methods of analysis, 187 
alkalinity of ash, 190 
calcium oxide, 190 

sucrate, 189 
fat, 187 

foreign, 188 
gelatin, 189 
preservatives, 188 
sucrose, 189 
preservatives, 186 
standards for, 186 
sucrate of lime in, 187 
test scale, 187 
viscogen in, 187 
Cream of tartar, 348 

in wine, 717, 732 
methods of analysis, 352 
Creatine, 35, 205 
Creatinine, 35, 205 
Creme de menthe, 786, 787 
Creme de Noyau, 786 

Creuss and Bettoli volatile acids method, 731 
Crocein orange, 815, 837, 847, 855, 871 
scarlet 8 B, 815, 851, 855, 870 
O, extra, 815, 855, 870 
Crude fiber, 286, 305 
Crustaceans, 262 
Crystal ponceau, 837, 855, 870 
violet, 857, 874 



Crystals, plant, 77 
Cucumber, composition of, 282 

pickles, 984, 985 
Cudbear, 819, 822 
Cumidin ponceau, see Ponceau 3 R. 

red, see Ponceau 3 R. 
Cuprammonia, 80 
Curacao, 786, 787 
Curcuma, 467 

Curcumin, 467, 856, 872. See also Turmeric. 
Curd tests in butter, 574, 576 
Curing meat, 215 
Currants, composition of, 283 
Curry powder, 467 
Custard powders, 279 
Cyan compounds, 29, 35 
Cyanol, extra, 846 854, 868 
Cystine, 35 

Dadhi, 174 

Date stones, 403 

Decker-Kunze theobromine and caffeine 

method, 413 
Defren-O'Sullivan sugar method, 137, 618 
Defren's sugar tables, 619 
Denis and Dunbar benzaldehyde method, 944 
Desiccated egg, 276 
Deutyro-proteose, 33 
Dextrin, 38, 597 

determination of, in cereals, 304 
honey, 672 
Jams and jel- 
lies, 999 
molasses, 654 
Dextrose, 37, 596 

determination of, 615, 618, 622, 
632, 656 
Diabetic foods, 373 

analyses, 374, 375 
Diamond yellow, 829 
Diastase, animal, 293 

in malt extract, 761 
starch methods, 292 
Dimethylglycolose, 36 
Dioses, 35 
Dioxin, 829 
Dioxyacetone, 36 
Disaccharides, 37 
Distilled liquors, 762 

aging, 764 



INDEX. 



1063 



Distilled liquors, methods of analysis, 777 
acids, 777 
alcoholsj 687 
aldehydes, 777 
caramel, 784 
color insoluble in 

amyl alcohol, 785 
water, 785 
esters, 777 
extract, 777 
' furfural, 778 

fusel oil, 778, 779 
methyl alcohol, 781 
opalescence of diluted 
distillate, 785 
standards, 763, 765, 766, 
772, 774 
Doolittle butter color test, 559 
Doremus gas apparatus, 971 
Double dilution sugar method, 650 
Dough, expansion of, 328 
Drained solids determination, 971 
Drains, 15 
Dried fruits, 1002 

decomposed, 1004 
lye treatment of, 1003 
moisture content of, 1004 
sulphuring of, 1003 
wormy, 1004 
zinc in, 1004 
Drugs, habit-forming, 1014 
Dry wines, 714, 719 

yeast, 344 
Dubois salicylic acid method, 890 

sugar method, 415 
Dubosc saccharimeter, 606 
Dulcin, 908 

detection, 908 
determination, 909 
Dunbar and Bacon malic acid method, 1008 
Dupouy peroxidase test 173 
Dupre color method, 736 
Dvorkovitsch theine method, 386 

Ebullioscope, 704 
Edam cheese, 197 
Edestan, ^^ 
Edestin, 308 
Eggs, 267 

ash of, 269 



Eggs, carbohydrates of, 267, 268 
cold storage, 273 
composition of, 268, 269 
desiccated, 276 
frozen, 275 
grades of, 272 
membrane, 269 
methods of analysis, 276 

ash, 277 

boric acid, 278 

ether extract, 277 

formaldehyde, 278 

lecithin, 278 

nitrogen, 277 

preservatives, 278 

salicylic acid, 278 

water, 277 
physical examination of, 276 
preservation of, 272 
shell, 269 
spoilage of, 274 
structure of, 267 
substitutes for, 278 
waterglass as a preservative, 273 
weights of, 267, 268 
white of, 269 

ash in, 269, 270 

carbohydrates in, 269, 270 

cholesterol in, 269 

composition of, 269 

fat in, 269 

lecithin in, 269 

ovalbumin in, 270 

ovomucin in, 270 

ovomucoid, in 270 

proteins in, 270 

water in, 269 
yolk of, 270 

cholesterol in, 271, 272 

fat in, 269, 270 

hematogen in, 272 

lecithin in, 271 

lutein in, 271, 272 

ovovitellin in, 271, 272 

proteins in, 271, 272 

solids in, 270, 271 

sugar, 271, 272 
Elaidin oil test, 533 
Elastin, 31, 205 
Electrolytic apparatus, 634 



1064 



INDEX. 



Elm bark, 442 
Emergency rations, 265 
Emmenthal cheese, 197 
Eosin, 815, 832, 849, 856, 872 

10 B, 849, 856, 872 
Ergot, 323 
Erika B, 855, 870 
Erioglaucin A, 854, 868 
Erucic acid, 29, 487 
Erythrodextrin, 598 
Erythrosin, 815, 826, 833, 834, 837, 850, 856, 

872 
Esters, in distilled liquors, 777 

imitation flavors, 956 
Estes vanillin method, 923 
Ether, ethyl, preparation of absolute, 55 

petroleum, preparation of, 55 
Eucasin, 203 
Eugenol, 426 
Evaporated milk, 176 
Ewe's milk, 113 
Exhaust pump, 18 
Exhausted cloves, 432 

ginger, 464 

tea leaves, 388 

vanilla beans, 913 
Extraction with immiscible solvents, 57 

volatile solvents, 52 
Extractor, Johnson, 54 

Soxhlet, 52 

" Faints," 764 

Farina, 371 

Farinaceous infants' foods, 371 

Fast acid fuchsin, 855, 869 

brown, 855, 870 

N, 856, 872 

red A, 837, 850, 856, 872 

B, see Bordeaux B. 

C. See Azorubin. 
E, 81S, 837, 85s, 869 

yellow R, 815, 854, 868 
Fat globules, 77 
Fats, 28, 486. See also Oils. 

classification, 29, 486 

filtering, 489 

measuring, 489 

methods of analysis. See Oils. 

microscopic examination of, 527 

paraffin in, 527 



Fats, weighing, 489 
Fatty acids, 29, 486 

constants of, 518 
insoluble, 502 
solidifying point of, 518 
soluble, 501 
volatile, 497, 499 
Fehling processes, 136, 614 

gravimetric, 137, 617 
AUihn, 632 
Defren-O'SuUivan, 

618 
Meissl-Hiller, 637 
Munson and Walker, 622 
volumetric, 137, 615 
solution, 614 

equivalents of, 616 
Fermentation, acetic, 788 

alcoholic, 682 
lactic, 116 
proteolytic, 117 
Fermented liquors, 707 
Feser's lactoscope, 148 
Fibrin, ^;^ 

Fibro-vascular tissue, 75 
Fibroin, 31 

Fiehe invert sugar test, 674 
Figs, composition of, 283 
Filberts, composition of, 284 
Filled cheese, 199 
Fincke formic acid method, 900 
Fish, 259 

canned, 263 
characteristics of, 261 
colors in, 265 
composition of, 259, 260 
fat in, 259 
milt, 261 

preservatives in, 265 
roe, 261 
salted, 263 
shell, 262 
smoked, 263 
Flaked wheat, 371 
Flavoring extracts, 911 
Flesh foods. See Meats. 
Fletcher and Allen tannin method, 384 
Floor, laboratory, 13 
Flour, 320 

acidity of, 321, 322 



INDEX. 



1065 



Flour, adulteration of, 324 
alum in, 325 
ash of, 321 
bakers, 320 
hsLvley, 323 
bleaching of, 325 

detection, 334 
buckwheat, 323 
I ^ by-products of, 320 
clear, 320, 322 
color of, 3 21/ 

composition of, 320, 322, 323 
corn, 323 
damaged, 323 
ergot in, 323 

gasoline color value of, 326, 327 
grades of, 320 
\^ Graham, 322 
; hard wheat, 321 
inspection, 326 
low grade, 320 
methods of analysis, 326 
absorption, 327 
acidity, 333 
albumin, 332 
alum, 334 
amides, 332 
ash, 330 

baking tests, 328 
bleaching test, 334 

chlorine, 335 
chloroform test, 336 
cold water extract, 2,33 
color test, Pekar, 326 

value, gasoline, 327 
dough expansion, 328 

test, 327 
fat, 330 

chlorine in, 336 
iodine number of, 333 
fiber, 330 
fineness, 326 
gliadin, 331 
globulin, 332 
(^ gluten, 331 

Bamihl test, 336 
glutenin, 332 
^ improvers, 333 

nitrous nitrogen, 33s 
protein, 330 



Flour, methods of analysis 

protein, alcohol soluble, 331 

salt soluble, 332 
water, 330 

soluble nitrogen, 332 
microscopy of, 337 
milling, 320 
patent, 320, 322 
red dog, 320 
rye, 323 
soft wheat, 321 
straight, 320 
whole wheat, 322 
Fluoborates, 901 

detection of, 902 
Fluorides, 901 

detection of, 902 
Fluosilicates, 901 

detection of, 902 
Foam producers, 1014 
" Foam " test for butter, 572 
Folin ammonia method, 226 

and Denis vanillin method, 922 
creatin and creatinin method, 255 
vanillin method, 922 
Food adulteration, 5 

analysis, commercial, 3 

from dietetic standpoint, 2 
general methods, 4 
and drugs act, 1041 
concentrated, 265 
fuel value, 38 
inspection, 3, 6 
misbranding, 6 

nature and composition of, 28 
official control of, i 
preservation, 876 
standards, 4 
Force, 371 
Fore milk, 114 
Foreshots, 764 
Formaldehyde, 879 

detection of, 165, 881 
determination of, 165, 880, 

883 
in eggs, 27s 
milk, 163 
Formic acid, 898 

detection of, 899 
determination of, 900 



1066 



INDEX. 



Fonnyl violet S 4 B, 856, 873 
Forster and Reichmann sterol method, 521 
Fortified wine, 714, 719, 723 
Freas drying oven, 19, 21 
Freezing-point, determination of, 849 
Fresenius color method, 367 
Frozen milk, 116 
meat, 214 
Fructose, d-, 596 

l-b-, 596 
Fruit, 283 

butter, 986 
candied, 678 
canned, 957 

methods of analysis, 970 
composition of, 283 
essences, artificial, 954, 955 
juices, 1004 

methods of analysis, 1007 
acidity, 1007, 1037 
citric acid, 1009 
malic acid, 1008 
proximate analysis, 285 
tartaric acid; 1008 
products, 957 
sugar. See Levulose. 
coated, 678 
in, 587 
syrups, loio 

tissues under the microscope, 1002 
Fruits, dried. See Dried fruits. 
Fuchsin, 831, 850, 857, 873 

acid. See Acid fuchsin. 
Fucose, 37 
Fuel value, 38 

calculation, 40 
Fuller caffein method, 1017, 1019 
cocaine method, 1018, 1019 
Funnel, jacketed, 489, 490 

separatory, 56, 57, 58 
Furfural, 295 

determination, 778, 810 
in distilled hquors, 778 
vinegar, 810 
Furnace, electric, 24, 51 

gas, 24 
Fusel oil, 763 

detection. 778 
determination, 779 
Fustic, 819, 823, 848 



Galatan, 38 
Galactose, 37 

Game, composition of, 211 
Gases, in spoiled cans, 960, 971 
Gasoline color value of flour, 326, 327 
Geerlig dry substance table, 645 
Geisler butter color method, 558 
Gelatin,' 31, 258 

determination, 228 
in cream, 186 

ice cream, 193, 195 
jams and jellies, 991 
standards, 258 
Gioddu, 174 

Gill and Hatch oil calorimeter, 512 
Gin, 776 
Ginger, 462 

adulteration of, 466 

ale, 1012 

black, 462 

composition of, 462, 463, 464 

exhausted, 464 

extract, methods of analysis, 952 

standards, 950 
liming of, 462 

methods of analysis, 465. See also 
Spices, 
cold water extract, 465 
microscopy of, 465 
oil of, 463 
root, 462 
standards, 466 
white, 462 
Girard and Dupre volatile oil method, 425 
Gliadin, 31, 307, 308, 309 

determination of, 308, 331 
Globulins, 31 
Globulose, 33 
Glucin, 910 
Glucose, commercial, 597 

composition of, 598 
determination of, 
in honey, 673 

jams and jellies, 999 
molasses, 651 
healthfulness of, 599 
in butter, 562 
methods of analysis, 661 
arsenic, 663 
ash, 663 



INDEX. 



1067 



Glucose, methods of analysis 
dextrin, 66i, 663 
dextrose, 661 
maltose, 661 
sulphurous acid, 661 
standards for, 599 
test for, 663 
Glucose, d-, 596 
Glutelins, 31 
Gluten, 308 

Bamihl te^t for, 336 
biscuit, 375 
determination of, 331 
flour, 373, 375 
Glutenin, 31,. 307, 309 
Glycerol in carbonated beverages, 1019 
vanilla extract, 913, 914, 926 
wine, 716, 734 
jelly, 73 
Glycerrhizin, 1014 
Glyco-leucine, 35 
Glycocoll, 35 
Glycogen, 205 

detection, 233 
determination, 234 
Glycolose, 36 
Glycoproteins, 32 
Goat's milk, 113 
Gooch boric acid method, 887 
Gorgonzola cheese, 197 
Gorter caffeine method, 397 
Graham flour, 322 
Grain, moisture in, 285 

sulphuring, detection, 287 
Grape juice, 1005 
nuts, 371 
sugar, 596 
Grapes, composition of, 283 
Gray water method, 553 
Green colors, 815, 846 
Grosse-Bohle formaldehyde test, 882 
Gruyere cheese, 197 
Guanine, 35, 205 
Guinea green B, 837, 857, 873 
Gums, 76 
Gunning-Arnold nitrogen method, 446 

nitrogen method, 58 
Gutzeit arsenic test, 65 

Habit-forming drugs, 1014 



Haemoglobins, 32 
Hajmolysis test for saponin, 1015 
Halphen cottonseed oil test, 537 
wine ratio, 723 

-Robin benzoic acid method, 562 
Hammarsten casein method, 412 
Hansen and Johnson tin method, 975 
Hanus iodine absorption method, 508 
Hartmann and Eoff tartaric acid method, 731 
Hauchecorne test, 532 
Heeren pioscope, 149 
Hefelmann Bombay mace test, 485 
Hehner formaldehyde test, 165, 881 

number, 502 

and Richmond milk formula, 138 
Heidenhain carbonic acid method, 353 
tartaric acid method, 356 
Hemicellulose, 294, 305 
Hess and Prescott vanillin and coumarin 

method, 920 
Hetero proteose, 2,2, 
Hickory nuts, composition of, 284 
Hiltner citral method, 934 
Hilyer benzoic acid method, 895 
Histidine, 35 
His tones, 32 
Hock wine, 715 

Hogg's protein nerve food, 204 
Holland acetyl value method, 516 
Holstein cows, milk from, 113 
Hominy, 371 

Homogenized fats, 177, 183, 186 
Honey, 664 

adulteration of, 668 

American, 665, 666 

Canadian, 664 

composition of, 664, 666, 667, 668 

Cuban, 667 

dextro-rotatory, 667, 668 

European, 664 

gelatin in, 670 

glucose in, 669 

Haitian, 667 

Hawaiian, 665, 666 

invert sugar in, 670 

methods of analysis, 670 
ash, 671 
dextrin, 672 
dextrose, 672 
glucose, commercial, 673 



1068 



INDEX. 



Honey, methods of analysis 

glucose, distinction from honey- 
dew honey, 674 
invert sugar, commercial, 674 
levulose, 671 
polarization, 671 
reducing sugars, 671 
sucrose, 672 
water, 670 
Mexican, 667 
Honeydew, 666, 667, 668, 674 
Hoods, 14, 19 
Hops, 739 

substitute, 741, 759 
Hordein, 31, 309 

Horseflesh, characteristics of, 232 
composition of, 219 
detection of, 232, 236 
glycogen in, 233 
Horseradish, 985, 986 
Hortvet number, of maple products, 659 
vinegar, 799 
volatile acid method, 731 
and West benzaldehyde method, 

944 
rose oil method, 953 
spice oil method, 951 
wintergreen oil method, 
948 
Hoskins electric furnace, 51 
Howard microscopic ketchup method, 980 
test for gums in ice cream, 196 
volatile oil method, 931, 948, 951 
Huckleberries, composition of, 283 
Hiibl iodine absorption method, 504 
Human milk, 113 

Hungarian red pepper. See Paprika. 
Hydrocyanic acid, 942, 946 
Hydrogen electrode, acidity by. See Acidity 

determination by hydrogen electrode. 
Hydrogen ion concentration. See Acidity de- 
termination by hydrogen electrode. 
Hydrogenated oils, 488, 580 
Hydrometer, 43 
Hypogaeic acid, 29, 487 
Hypoxanthine, 35, 205 

Ice cream, 191 

classification, 192 
cones, 193 



Ice cream, homogenized, 193 

ingredients, influence of, 192 
methods of analysis, 193 
colors, 196 
fat, 193 

foreign, 195 
gelatin, 196 
gums, 196 
preservatives, 196 
starch, 196 
t?iickeners, 195 
process, influence of, 192 
standards, 191 
Ichthulin, 32 
Imitation coff'ee, 398 
Immersion refractometer, 97 
adjustment of scale, 99 
distilled water readings on, 99 
investigation of small quantities of 
solutions by, loi 
of solutions excluded from air by, loi 
milk examination by, 151 
scale readings compared with no, 102 
solutions standardized by, 106 
temperature corrections for, 107 
Incinerator, 158 
Indicators, 27 

Indices of refraction, 91, 102 
Indigo, 815, 824 

carmine, 826, 830, 833, 834, 838, 846, 

854, 868 
disulphosacid. See Indigo carmine. 
Indigotine. See Indigo carmine. 
Indol, 79 
Indophenol, 830 
Induhn, 830 
Infants' foods, 371 

classification of, 372 
composition of, 373 
effects of heating on, 376 
methods of analysis, 375 
carbohydrates, 376 
cold water extract, 376 
fat, 375 

starch, sugar, and dex- 
trin, 376 
microscopy of, 377 
preparation of, 372 
Inosite, 38 
Inspection of flour, 326 



INDEX. 



10G9 



Inspection of foods, 3, 5, 6, 9 
liquors, 684 
milk, 144 
Inulin, 38 
Invalids' foods, 371. See also Infants' 

Foods. 
Inversion, 611, 612 
Invert sugar, 586, 611, 612 

commercial, 668, 670 

tests for, 674 
detection ol, 613 
determination of, 613, 622, 637 
distinction from maltose and 

lactose, 655 
in honey, 668, 670 
lodeosin, 826 
Iodine absorption of oils, 504, 507 

in potassium iodide, 78 
Irisamin G, 857, 874 
Irish whiskey, 767 
Iron oxide determination, 312 
Iso-leucine, 35 

-oleic acid, 29, 487 

Jams, 989 

adulteration of, 990 
agar agar in, 991, 1002 
apple stock in, 990, 991 
coagulator in, 991 
coloring matter in, 990, 1000 
composition of, 992, 993, 995 
compound, 994 
fruit tissues in, 1002 
gelatin in, 991, looi 
glucose in, 990, 999 
methods of analysis, 995 

acidity, 996 

agar agar, 1002 

ash, 996 

colors, 1000 

dextrin, 999 

fiuit tissues, 1002 

gelatin, loor 

glucose 999 

pectin, 1000 

polarization, 997 

preservatives, 1001 

protein, 997 

sampling, 995 

solids, 996 



Jams, methods of analysis 

solids, insoluble, 996 

starch, 1001 

sugars, 997 

sweeteners, looi 
starch in, 991 
Jellies. See Jams. 
Jensen-Kirschner number, 501 
Johnson extractor, 54 

-Chittenden-Gautier arsenic method, 

63 
Jones soluble fatty acids method, 501 
Jorissen dulcin test, 909 

salicylic acid test, 889 
Juckenack color method, 367 

lecithin phosphoric acid method, 
366 

Kalama, 819, 823 

Kefir, 174 

Kelley electrical apparatus, 1029 

Kenrick tartaric acid method, 357 

Keratins, 31 

Ketchup, 977 

citric acid in, 979 
colors in, 980, 981 
composition of, 978 
decayed material in, 979 
foreign pulp in, 980, 984 
lactic acid in, 979, 983 
manufacture, 978 
methods of analysis, 981 
acidity, 982 

volatile, 981 
ash, 981 
citric acid, 982 
colors, 981 
foreign pulp, 984 
lactic acid, 983 
preservatives, 981 
sand, 981 
solids, 981 

soluble, 982 
insoluble, 981 
specific gravity, 981 
sugars, 982 
microscopy of, 980, 984 
organisms in, 979 
preservatives in, 980, 981 
refuse in, 978 



1070 



INDEX. 



Ketchup, standards, 977 
Ketoses, 36 

Kjeldahl nitrogen method, 61 
Klostermann digitonin test, 525 
Koelner baking test, 328 
Koettstorfer saponification method, 503 
Konig and Karsch method for distinguish- 
ing honeydevv and glucose, 674 
Krober pentosans and pentoses table, 297- 

303 
Kumis, 174 
Kvimmel, 787 
Kuntze mustard oil method, 474 

Laboratory benches, 13 

stain for, 14 
drains, 15 
equipment, 12 
floor, 13 
hoods, 14 
lighting, 13 
location, 12 
sinks, 15 
ventilation, 13 
Lactalbumin, 30, no, 204 
Lactated infants' foods, 372, 373 
Lactic acid, 38 

in ketchup, 979, 983 
tomatoes, 979 
Lactoglobulin, no 
Lactometer, 148 
Lactoscope, 148 
Lactose, 37, 109, in, 112, 599 
Defren table for, 619 
detection of, 655 
determination of, 615, 617, 618, 622 

in milk, 137 
distinction from invert sugar and 

maltose, 655 
Munson and Walker table for, 623 
Soxhlet table for, 139 
Lager beer, 739 
Lakes, 817 

detection of, 817 
Lamb, composition of, 210 

cuts of, 210 
Lard, 577 

adulteration of, 581 
back, 577 
composition, 577, 581 



Lard, composition affected by feeding, 579 
" compound," 580, 581 

nickel in, 580 
constants of, 528, 529, 578, 579, 581 
iodine number, 578 
leaf, 577, 578 
methods of analysis, 582 
beef fat, 582 
nickel, 584 
microscopy of, 5S2 
neutral, 564, 565, 578 
oil, 579 
oily hogs, 579 
standard, 579 
stearin, 579 
substitutes, 580 
Laurent saccharimeter, 606 
Laurie acid, 29, 486 
La Wall chicory test, 403 

and Bradshaw benzoate method, 893 
Law, food and drugs, 1041 
meat inspection, 1045 
Leach coumarin test, 923 

formaldehyde test, 165, 881 
and Lythgoe malic value method, 657 
methyl alcohol method, 781 
Lead chromate, 647, 816 

number, maple products, 658 
vanilla extract, 925 
vinegar, 791 
salts of, 351, 961 

determination of, 362, 973, 976 
Leavening materials, 343, 348 
Lebbin formaldehyde test, 882 
Leben, 174 
Lecitalbumin, 32 
Lecithin, 29, 35 

determination of, 278, 366 
nucleovitellin, 32 
Lecithoproteins, 32 

Leeds and Evcrl.art method for potassium 
myronate, sinapin thiocyanate and my- 
osin, 473 
Leffmann and Beam gelatin method, looi 

volatile fatty acids 
method, 499 
Legumelin, 30 
Legumes, 281 

ash of, 310 
Legumin, 30, 31, 309 



INDEX. 



1071 



Lemon extract, 927 

adulteration of, 928 
composition of, 930 
methods of analysis, 929 

alcohol, 932 

aldehydes, 933 

ash, 936 

citral, 934 

citric acid, 937 

colors, 936 
/ glycerol, 937 

lemon oil, 929, 930, 

932, 9.37 
methyl alcohol, 935 
solids, 936 
tartaric acid, 937 
methyl alcohol in, 935 
preparation of, 927 
standard for, 927 
terpeneless, 928 
juice, ICX36 
oil, 927, 928, 937 

determination of, 930, 932 
examination of, 937 
methods of analysis, 939 
alcohol, 941 
aldehyde, 940 
citral, 940 
pinene, 941 
refraction, 939, 940 
rotation, 939, 940 
specific gravity, 939 
terpeneless, 929 
soda, 1012, 1013 
Lemongrass oil, 929, 938, 939 
Lemons, composition of, 283 
Lendrich and Nottbaum caffeine method, 397 
Lentils, 281 

Lettuce, composition of, 282 
Leucine, 35 

Leucosin, 30, 306, 307, 308, 309 
Levallois bromine absorption method, 510 
Levulose, 37, 596 

determination of, 671 
Lewkowitsch acetyl value method, 5x4 
Ley test for invert sugar in honey, 674 
Ley -Emery melting-point method, 583 
Lieberman-Storch rosin oil test, 548 
Liebig's meat extract, 242, 246, 247, 248 
Light green, 826, 833, 834, 837, 838, 846 



Lighting, 13 
Lignin, 81 

Lignoceric acid, 29, 487 
Limburger cheese, 197 
Lime, determination of, 312, 361 
in baking powder, 351, 352 

spices, 424 
juice, 1006 
sucrate of, 187 

water, in vinegar analysis, 796 
Liming of ginger, 462 
Limonene, 938, 939 
Linolenic acid, 29, 487 
Linolic, 29, 487 
Linseed oil, 547 

constants, 528, 529 
Liqueurs, 786 

analysis of, 787 
Liquor inspection, 684 
Liquors, 682 

distilled. See Distilled liquors, 
fermented. See Fermented liquors, 
malt. See Malt liquors, 
malted and non-malted, 743 
methods of analysis, 686 
alcohol, 686, 687 
ash, 706 

preservatives, 706 
specific gravity, 687 
sweeteners, 706 
state control of, 683 
toxicity of, 684 
Litmus, 815, 819, 822, 846 
Lobster, composition of, 262 
Lowenthal-Procter tannin method, 383 
Logwood, 819, 821, 822, 852 
Long fermentation baking test, 329 

pepper, 445, 446, 452 
Loomis color scheme, 845 
Lovibond tintometer, 67 . 
Low butter color method, 558 

wines, 764 
Lj^e treatment of fruit, 1003 
Lythgoe sucrose test, 189 

Macaroni, 364. See also Pastes, edible. 
Macassar mace, 482, 483, 484 
Mace, 480, 482 

adulteration of, 484 

Bombay, 483, 484, 48'; 



1072 



INDEX. 



Mace, composition of, 483 
Macassar, 482, 483 

methods of analysis, 485. See also 
Spices. 
Bombay mace, 485 
microscopy of, 484 
standards, 484 
Madeira wine, 715, 717 
Magenta. See Fuchsin. 
Magnesia determination, 312 
Maize. See Corn. 
Malachite green, 815, 846, 857, 874 

G, 857, 874 
Malic acid, 38 

in cider, 709, 1008 
fruit juices, 1008 
vinegar, 790, 791, 798 
wine, 716 
value of maple products, 657 
Malt, 738 

extracts, 761 

liquors, 738. See also Beer. 
substitutes, 741, 744 
vinegar, 792, 804 
Malting, 738 
Maltose, 37, 597 

detection of, 655 
determination of, 618, 622 
distinction from invert sugar and 
lactose, 655 
Mannan, 38 
Mannose, 37 
Maple sap, 591 

sugar, 591. See also Maple syrup, 
syrup, 591 

adulteration of, 594 
composition of, 592, 593 
methods of analysis, 656 
ash, 657 

electrical conductivity, 66 1 
lead number, 658 
malic acid, 657 
reducing sugars, 657 
sucrose, 657 
water, 656 
standards, 594 
Maraschino, 786 

cherries, 988 

benzaldehyde in, 988 
Mare's milk, 113 



Marpmann color method, 241 
Marsh arsenic test, 64, 760 
test for caramel, 784 
Martin color scheme, 557 
Martins yellow, 815, 829, 847, 856, 872 
" Materna " milk modifier, 144 
Mathewson color method for butter, 559 

dry colors, 853 
dyed fibers, 853 
quantitative sep- 
aration, 836 
separation by im- 
miscible sol- 
vents, 859 
Maumene thermal test, 511 
Mayrhofer glycogen method, 234 
Mazun, 174 

McGill lead number, 659 
Meal, corn or maize, 337 
Meat, 205 

acids in, 216, 230 

adenine in, 205 

ash of, 206, 230 

bases, 205, 219, 230, 247, 248, 249, 256 

boric acid in, 216, 238 

canned, 218, 219 

adulteration of, 218 
composition of, 218 
carnitine in, 205 
carnosine in, 205 
cold storage of, 213 
collagen in, 205 

composition of, 205, 206, 208-212 
connective tissue of, 205 
cooking, effect of, 217 
corning of, 215 
creatine in, 205 
creatinine in, 205 
curing of, 215 
drying of, 215 
elastin in, 205 
extracts, 242 

albumoses in, 243 
bouillon cubes, 250 
carnitine in, 243 
carnosine in, 243 
chlorine in, 244 
composition of, 243, 246-249 
creatine, in, 243, 255 
creatinine in, 243, 255 



INDEX. 



1073 



Meat extracts, gelatin in, 243 

hydrolysis products of, 244 
manufacture of, 242 
meat bases in, 243 

seasonings, 245 
methods of analysis, 253 - 
acidity, 257 
ammonia, 253 
ash, 253 

coagulation point, 258 
creatine, 255 
creatinine, 255 
glycerol, 258 
nitrogen, total, 253 
preservatives, 258 
protein, coagulable, 254 

insoluble, 253 
proteoses, 254 
purine bases in, 256 
sugars, 258 
tannin-salt precipitate, 

254 
water, 253 
methyl guanidine in, 243 
peptones in, 243 
preservatives in, 216, 25S 
proteoses in, 243, 254 
purine bases in, 243 
standards, 252 
yeast extract, distinction 
from, 252 
fat, 205, 224 

composition of, 207, 212 
glycogen in, 205, 233, 234 
guanine in, 205 
hypoxanthine in, 205 
inosite in, 206 
inspection, 207 

law, 1045 
juices, 244 

methods of analysis, 223 
acidity, 230 
ammonia, 225 
ash, 230 

benzoic acid, 238, 239 
boric acid, 238 
collagen, 228 
colors, 240 
constants, 224 
creatine, 230 



Meat, methods of analysis 
creatinine, 230 
fat, 224 
frozen, 241 
gelatin, 228 
glycogen, 233, 234 
horse flesh, 232, 236 
meat bases, 230 
myosin, 229 
nitrogen, 225 

insoluble, 227 
peptones, 230 
protein, coagulable, 229 
proteoses, 230 
purine bases, 230 
starch, 231, 234, 240 
sugars, 237 
sulphurous acid, 238 
water, 223 
methyl guanidine in, 205 
mince, 987 
muscle fibers of, 205 
myogen of, 205 
myosin of, 205, 229 
{)ickled, 215 
plasma of, 205 
preservation of, 214 
])reservatives in, 216 
ptomaines in, 217 
refrigeration of, 214 
salted, 215 
saltpeter in, 215 
sarcolemma of, 215 
serum of, 205 
smoked, 215 
spoilage, 205 
standards of, 213 
sugar in, 206 

sulphurous acid in, 216, 238 
unwholesome, 213 
xanthine in, 205 
Meissl-Hiller invert sugar method, 637 

table, 638 
Melibiose, 37 

Melting point determination, 496 
Mercury compounds in colors, 815 
Metachrome orange R, 856, 872 
Metallic salts in canned goods, 961 

determination, 973, 974. 97^ 
Metanil yellow, 815, 837, 848, 856, 871 



1074 



INDEX. 



Metaproteins, 33 
Metaraban, 38 

Methyl alcohol, detection of, 781, 935 
alkali blue, 857, 873 
dioses, 36 
pentoses, 37 
tetroses, 36 

violet, 815, 846, 851, 874 
Methylene blue, 815, 830, 846, 857, 873 
Micro-chemical reactions, 81 
Micro-polariscope, 71 
Microscope in food analysis, 68 
reagents for, 77 
stand, 69 
Microscopical accessories, 71 
analysis, 68 
apparatus, 69 
diagnosis, 73 
reagents, 77 

anal3"tiral, 78 
clarifying, 79 
standards, 69 
technique, 72 
Microscopy of agar agar, 1002 
allspice, 436 
arrowroot, 291 
barley, 317 

starch, 290 
bean, 400 

starch, 291 
buckwheat, 319 

starch, 290 
butter, 574 
cassia, 440 
cayenne, 458 
cereal products, 314 
charlock, 477 
chicory, 400 
cinnamon, 440 
cloves, 430 
cocoa, 418 
cocoanut shells, 433 
coffee, 399 
corn, 317 

starch, 290 
date stones, 403 
fats, 527 
flour, 315, 337 
fruit tissues, 1002 
ginger, 465 



Microscopy of honey, 664 
jams, 1002 
ketchup, 980, 984 
lard, 582 
mace, 484 
milk, 108 
mustard, 475 
nutmeg, 481 
oats, 318 
oat starch, 291 
oils, 527 
^'oleomargarine, 574 
olive stones, 450 
paprika, 458 
pea, 4CX3 

starch, 291 
pepper, black, 447 
long, 452 
red, 458 
white, 447 
potato starch, 291 
rice, 319 

starch, 291 
rye, 316 

starch, 290 
sago, 291 
sawdust, 460 
starches, 289 
tapioca starch, 291 
tea, 391 
turmeric, 468 
wheat, 315 

starch, 289 
Micro-technique, 72 
Milk, 108, 140 

acidity of, 108, 1033 
adulteration of, 144 
aldehyde reductase in, 112 
anilin orange in, 160 
annatto in, 160 
ash of, III, 112, 121 
ass's, 113 
bacteria in, 117 
benzoic acid in, 167 
bitter, 117 
blue, 117 

boric acid in, 166, 170 
cane sugar in, 171 
catalase in, 112 



INDEX. 



1075 



Milk chocolate, 410 

citric acid in, no, iii 
color of, 109 
coloring matter in, 159 
composition of, iii, 112 

changes during lactation, 114 

influence of age, 115 

breed, 115 
feed, n6 
freezing, 116 
/ intervals between 
milking, 116 
condensed, see Condensed milk. 

skimmed in, 171 
enzj^mes in, no, 117 
evaporated, 176 
ewe's, 113 
fat of, 109, III, 121 
fermentations of, 116 
fermented, 174 

methods of analysis, 175 
fibrin in, no 
fore milk, 113 

formaldehyde in, 163, 165, 170 
goat's, 113 
homogenized, 172 
human, 113 

hydrogen peroxide in, 167 
inspection, 144 
known purity, 146 
lactalbumin in, no 
lactoglobulin in, no 
lactose in, no, 134 
mare's, 113 
methods of analysis, 117, 148, 154 

acidity, 140, 1033 

adsorption, 154 

albumin, 133 

amino compounds, 133 

ammonia, 133 

anilin orange, 162 

annato, 161 

ash, 121 

boric acid, 166, 170 

capillarity, 154 

caramel, 161 

casein, 132 

caseoses, 133 

colors, 160 

electrical conductivity, 154 



Milk, methods of analysis 
fat, 121 

centrifugal, 122 
gravimetric, 121, 122 
refractometric, 126 
formaldehyde, 165, 170 
freezing-point, 153 
hydrogen peroxide, 168 
lactose, 134 

by copper reduction, 136 
polarization, 134 
oxidation index, 154 
peptones, 132 
proteins, 132 

by calculation, 140 
gravimetric, 132 
sampling, 117 
sodium bicarbonate, 167, 170 

carbonate, 167, 170 
specific gravity, 118 

heat, 154 
starch, 171 
total solids, 119 

by calculation, 140, 

141 
gravimetric, 119 
viscosity, 154 
microscopy of, 108 
modified, 142 
pasteurized, 173 

aldehyde reductase test 

for. 174 
peroxidase test for, 173 
tests for. 173 
peroxidase in, no 
powder, 184 

composition, 185 
methods of analysis, 185 
fat, 185 
lactose, 185 
preservatives in, 162 
protein preparations, 203 
proteins of, 109, ni; 132 
records of analysis of, 157 
red, 117 

reductase in, no 
ropy, 117 

salicylic acid in, 167 
sampler, 118 
serum, composition, 151 



1076 



INDEX. 



Milk serum, nitrates in, 151 

preparation of, 150 
refraction of, 151 
specific gravity of, 151 
skimmed, 146 
sodium bicarbonate in, 167 

carbonate in, 167 
sour, analysis of, 172 
souring of, 116 
standards, 145 
strippings, 113 
sugar. See Lactose, 
systematic examination of , 154 
ash, 15s 
fat, 155 

total solids, 155 
watering of, 146 
yellow, 117 
Mill bromine absorption method, 510 
Millet, composition of, 280 
Milliau cottonseed oil test, 536 
Millon reaction, 34, 79 

reagent, 79 
Mince meat, 987 

adulteration of, 987 
condensed, 987 
standards, 987 
Mineral colors, 815, 816 

content of food, 38 
Mirbane, oil of, 943, 945 
Mitchell and Smith fusel oil method, 780 

lemon oil methods, 930, 931 
Modified milk, 142 
Mohler benzoic acid test, 892 
Moisture, determination of, 49 
Molasses, 589 

adulteration of, 651 
composition of, 589 
methods of analysis, 642 
ash, 644, 654 
dextrin, 654 
dextrose, 656 
glucose, commercial, 651 
raffinose, 650 
reducing sugars, 651 
solids, 643 
sucrose, 644, 656 
tin, 655 
standard, 651 
vinegar, 794 



MoUusks, 262 

Monosaccharides, 36 

Morpurgo dulcin test, 909 

Moslinger lactic acid method, 732 

Mucins, 32 

Munson heavy metals method, 973 

and Tolman pectin method, 1000 
Walker sugar method, 136, 294, 
622 
table, 623 
Muscle fibers of meat, 205 

sugar, 206, 237 
Muscovado, 588, 589 
Mushroom ketchup, 977 
Mushrooms, composition of, 282 
Muskmelons, composition of, 283 
Mustard, 469 

adulteration of, 476 
ash of, 473 
black, 469 
brown, 469 
cake, 470 
colors in, 476, 478 
composition of, 471, 472 
flour, 470 
Indian, 469 

methods of analysis, 473, see also 
Spices, 
myrosin, 473 

potassium myronate, 473 
sinapin thiocyanate, 473 
volatile mustard oil, 473 
microscopy of, 475 
myrosin in, 469 
oil, fixed, 470, 540 

volatile, 470 
pickles, 985 

potassium myronate in, 470, 473 
prepared, 478 

adulteration of, 478 
composition of, 478 
methods of analysis, 479 
ash, 479 

ether extract, 479 
fiber, 479 
protein, 479 
reducing matters, 479 
salt, 479 
solids, 479 
sinalbin in, 470 



INDEX. 



1077 



Mustard, sinalbin mustard oil in, 470 

sinapin thiocyanate in, 469, 473 

sinigrin, 470 

standards, 476 

starch in, 476 

turmeric in, 476 

volatile oil of, 470, 473 

white, 469 

wild, 469, 470, 477 
Mutton, composition of, 210 

cuts of, 2ICT 

tallow, 528, 529 
Myosin, 31 

determination, 229 
insoluble, ^^ 
Myristic acid, 29, 486 

Naphthol black B, 815, 854, 869 

green B, 815, 829, 846, 854, 869 

orange, 826 

yellow. See Martius yellow. 

S, 369, 81S, 837, 838, 847, 
85s, 869 
Natural wines, 714 

Nelson-La Wall-Doyle capsicum method, 952 
Nessler free tartaric acid method, 731 
Neubauer-Lowenthal tannin method, 735 
Neufchatel cheese, 197 
New blue, 857, 873 

coccin, 815, 837, 851, 854, 868 
Nickel salts, 968, 977 

detection, 584 
determination of, 977 
Night green 2 B, 856,' 873 
Nigrosin, soluble, 830, 854, 868 
Nile blue, 830 
Nitrates in food, 29, 35 

watered milk, 151 
Nitrobenzol, 943, 945 
Nitrogen, amino acid, 63 

apparatus, 58, 60, 61, 62 
compounds in milk, 109, 132 
determination of, 58, 60 
free extract, 287 
protein, 63 
Nitrogeneous bodies, 29 

classification of, 29 
separation of, in cheese, 200 
meat, 226 
milk, 132, 133 



Niviere and Hubert fluorine method,- 902 

Noodles, 364. See also Pastes, edible. 

Notification, 10 

Noyau, 786 

Nuclein, 32 

Nucleoproteins, 32 

Nutmeg, 480 

adulteration of, 482 

composition of, 481 

extract, 950, 952 

Macassar, 480, 482 

methods of analysis. See Spices. 

microscopy of, 481 

oil of, 480, 950, 952 
standard, 950 

standards, 482 
Nutrose, 203 
Nuts, composition of, 284 

Oats, analyses of, 280, 281 
ash of, 310 

microscopic structure of, 318 
starch, 291 
Oil, anise, 950 

basil, 950 

bitter almond, 942, 943 

cakes, eflfects on butter of feeding, 552 
lard of feeding, 579 

calorimeter, 512 

cassia, 950 

celery seed, 950 

charlock, 540 

cinnamon, 950 

cloves, 950 

cocoanut, 549 

corn, 541 

cottonseed, 535 

ginger, 463 

lard, 579 

lemon, 928, 929, 930 

terpeneless, 928 

lemongrass, 929, 938, 939 

linseed, 547 

marjoram, 951 

mustard, fixed, 470, 540 
volatile, 470 

nutmeg, 950, 952 

oleo, 564 

olive, 530 

orange, 941 



1078 



INDEX. 



Oil, palm kernel, 550, 565 

peanut, 542 

peppermint, 948 

poppyseed, 547 

rape, 539 

rose, 953 

rosin, 548 

savory, 950 

sesame, 537 

soy, 545 

spearmint, 949 

staranise, 950 

sunflower, 547 

thyme, 95 1 

wintergreen, 947, 948 
Oils, 486. See also Fats. 

acetyl value of, 514, 515, 528 

bromination test, 511 

bromine aBsorption of, 509, 510 

cholesterol in, 520, 521 

composition of, 486, 487 

constants of, 528, 529 

constituents of, 486 

elaidin test, 517 

fatty acids of, 486, 487, 518, 529 

insoluble, 503, 518, 529 

hydrogenation of, 4S8, 584 

iodine, number of, 504, 507, 528 

Jensen- Kirschner number, 501 

judgment as to purity of, 488 

Maumene number of, 528 

melting point, 497, 528 

methods of analysis, 488 
acetyl value, 514, 516 
bromination test, 511 
bromine index, 509 
cholesterol, 521, 522 
elaidin test, 517 
fatty acids, free, 518 

insoluble, 502 
soluble, 521 
iodine number, 504 
Jensen-Kirchner number, 501 
Koettstorfer number, 503 
Maumene number, 511 
melting point, 496 
phytosterol, 521, 522 
Polenske number, 499 
refraction, 493 
Reichert-Meissl number, 497 



Oils, methods of analysis 

saponification number, 503 

solidifying point, 496 

specific gravity, 490 

thermal tests, 510 

titer test, 518 

unsaponifiable matter, 520 

Valenta test, 517 

viscosity, 492 

volatile fatt}' acids, 497 
microscopy of, 527 
phytosterol in, 520, 521 
Polenske number of, 500, 529 
rancidity of, 489 
refraction of, 493, 494, 528 
Reichert-Meissl number of, 497, 500, 

saponification of, 487 

number of, 499, 503, 504, 
528 
sitosterol in, 542 

solidifying point of, 496, 497, 528 
solubility of, 486 
specific gravity of, 490, 492, 528 

factors, 491 
thermal tests, 510 
titer test, 518, 529 
unsaponifiable m^atter in, 520, 529 
Valenta test, 517 
viscosity of, 492 
Oleic acid, 29, 487 
Oleo oil, 564 
Oleomargarine, 563 

adulteration of, 566 
coloring of, 565 
constants of, 528, 529 
distinction from butter, 567, 571 
fat, constants, 528, 529, 567 
Polenske number of, 571 
refraction of, 568 
Reichert-Meissl number of, 570 
healthfulness of, 567 
manufacture of, 563 
microscopic examination, 574 
odor and taste, 567 
palm oil in, 565 
refraction of, 568 
vegetable, 576 
Zega's test for, 576 
Olive oil, 530 



INDEX. 



1079 



Olive oil, adulteration of, 534 
composition of, 531 
constants, 528, 529, 531, 532 
methods of analysis, 532, 533, 534, 
See also Oils, 
elaidin test, 533 
Hauchecorne test, 532 
preparation of, 530 
refraction of, 533 
standard, 531, 532 
substitutes,, 531 
stones, 450 
Olives, pickled, 985 
Onions, composition of, 282 
Orange 2, 815, 837, 838, 847, 855, 871 

I, 815, 837, 838, 848, 855, 871 

II. See Orange 2 
IV, 815, 848, 856, 871 
colors, 815, 847 
extract, 941 

standards, 942 
terpeneless, 942 

G, 837, 847, 854, 869 

oil, 941 

R, 855, 871 

soda, IOT2, 1013 
Orchil. See Archil. 

Ortho-tolueneazo-j3-naphthylamine, 858, 875 
O'Sullivan-Defren sugar method, 614 
Ovalbumin, 32, 270 
Oven, drying, 19 

McGill, 609 
Ovomucin, 270 
Ovomucoid, 32, 270 
Oxygen absorbed, 429 

equivalent, 429 
Oxyha;moglobin, 32 
Oxy proline, 35 
Oysters, 262 



Palas rapeseed oil test, 540 

Palatine red, 855, 870 

scarlet, 854, 869 

Palm kernel oil, 850, 865 

Palmitic acid, 29, 486 

Paprika, 453 

added oil in, 461 
adulteration of, 460 
composition of, 456, 457 



Paprika, methods of analysis, 461. See also 
Spices, 
olive oil test, 461 
microscopy of, 458 
standard, 460 
Para red, 858, 875 
Parafl&n in beeswax, 675 

confectionery, 679 
fats, 527 

oleomargarine, 566 
Paranuclein, 201 
Parenchyma, 74 
Parsnips, composition of, 282 
Pastes, edible, 363 

adulteration of, 365 

artificial colors in, 365, 366 

composition, 364 

Italian, 363 

lecithin phosphoric acid in, 

364, 366 
methods of analysis, 366 
artificial colors, 366 
lecithin phosphoric acid, 366 
nitrogen soluble in water, 366 
precipitin test for eggs, 366 
noodles, 364 
Patent blue, 846, 854, 868 

A, 857, 873 
Patrick ice cream thickener test, 195 

water method, 553 
Paul foreign fats method, 183 
Pea, composition, 281 
proteins of, 309 
starch, 291 
Peanut oil, 542 

adulteration of, 542 
composition of, 542 
constants, 528, 529 
methods of analysis, 543. See 
also Oils. 
Bellier test, 544 
Renard test, 543 
standards, 542 
Peanuts, composition of, 284 
Pear cider, 712 

essence, imitation, 954, 955 
'Pears, composition of, 283 
Pecans, composition of, 284 
Pectin determination, 1000 
Pectose, 38 



1080 



INDEX. 



Pekar flour color test, 326 
Pentosans, 38 

determination of, 294, 305 
in cocoa products, 41a 
table for, 297 
Pentoses, 36, 297 
Pepper, 442 

adulteration of, 449 
black, 442 
buckwheat in, 451 
composition of, 442 
long, 445, 446, 452 
methods of analysis, 422, 446. See 
also Spices, 
nitrogen, in ether extract, 447 

total, 446 
piperin, 447 
microscopy of, 447 
olive stones, 450 
piperin in, 443, 447 
red. See Cayenne and Paprika, 
shells, 445, 446, 449 
standard, 449 
varieties of, 442 
white, 442 
Peppermint extract, 948 

methods of analysis, 949 
standards, 949 
oil, 948 
Peptides, 34 
Peptones, ^^ 

in cheese, 201 
meat, 205, 230 
milk, 133 
Perry, 712 

Persian berries, 819, 823 
Peter benzoic acid test, 892 
Petroleum ether, 55 
Phenylalanine, 35 
Phloroglucide, 295, 296 
Phloroglucinol, 296 
Phloxin, 815, 849, 856, 872. See also Eosin 

10 B. 
Phosphate baking powders, 350 
Phosphin, 831 
Phosphoproteins, 32 

Phosphoric acid determination, 313, 362, 757 
in baking chemicals, 362 
beer, 757 
Phosphotungstic acid reaction, 34 



Photomicrography, 80 

camera for, 83 
Phytosterol, 486 

acetate test, 525 
crystallization of, 522 
determination of, 521 
distinction from cholesterol, 521 
separation of , 522 
Piccalilli, 985 
Pickled meats, 213, 215 
Pickles, 984 

adulteration of, 986 
composition of, 985 
Pickling pump, 216 
Picric acid, 815, 847, 855, 871 
Pie filling, 987 
Pimento. See AUspice. 
Pimiento, 452, 456, 457 
Pineapple essence, imitation, 954, 955 
Pineapples, composition of, 283 
Pioscope, 149 
Piperidine, 35, 443 
Piperin, 35, 443 

determination of, 447 
Pistachios, composition of, 284 
Piutti and Bentivoglio color method, 368 
Plant crystals, 77 
Plasmon, 203 
Plastering, of wine, 721 
Platinum dishes, 119, 155 

counterweights for, 155 
Plums, composition of, 283 
Poisoned foods, 63 
Poivrette, 450 
Poke berry, 819, 823 

Polariscope, 600. See also Saccharimeter. 
micro, 71 
tube jacketed, 671 

short, for oils, 937, 939 
Polarization at high temperature, 671 
of essential oils, 938 
honey, 671 
jams and jellies, 997 
lemon extract, 930 
molasses, 644 
orange extract, 942 
sugar, 610 
vinegar, 800 
wine, 722, 734 
Polenske number, 499 



1 



INDEX. 



1081 



Polenske GrujiC fat method, 343 
Ponceau 4 GB. See Crocein orange. 

2 R, 815, 837, 851, 855, 869 

3 R, 837, 838, 851, 855, 870 
6 R, 837, 851, 854, 868 

Poppyseed, 547 

oil, 547 
Pork, composition of, 211 

cuts of, 211 
Port wine, 714, 715, 717, 718 
Porter, 740, 743. Seje also Beer. 
Potash determination, 313, 361 
Potassium myronate, 470 
Potato starch, 291 
Potatoes, composition of, 282 

starch of, 291 
Poultry, composition of, 211 

drawn vs. undrawn, 217 
Prall-Kerr nickel method, 584 
Pratt citric acid method, 1009 
Preparation of sample, 43 
Preservatives, 876 

commercial food, 878 
in butter, 560 

canned goods, 969 

carbonated beverages, 1013 

fish, 265 

fruit juices, 1005 

jams and jellies, looi 

ketchup, 980 

meats, 216 

milk, 162 

preserves, 987 

wine, 725, 736 
of eggs, 272, 278 
regulation of, 877 
Preserves, 986 
Pressure pump, 18 
Price-Estes color method, 833 

-IngersoU color method, 833 
Primulin, 831 
Process butter, 563 
Prolamins, 31 
Proline, 35 
Proof spirit, 763 
Prosecution, 10 
Protamins, 32 
Proteans, 33 
Protein grains, 77 
Proteins, classification, 29 



Proteins, coagulated, 33 
conjugated, 32 
derived, ss 
factor for, 29 
occurrence, 29 
of barley, 309 
beer, 757 
cereals, 305 
corn, 309 

eggs, 270, 271, 272 
milk, 109 

calculation of, 140 
determination of, 132 
peas, 309 
rye, 309 
wheat, 305 
simple, 30 
tests for, 34 
Proteolytic fermentation, 117 
Proteoses, 33, 243, 246, 247, 249, 307, 309 

determination of, 254 
Proximate analysis, expression of results of, 
41 
extent of, 41 
Prunes, composition of, 283 
Prussian blue, 816 

in tea, 387, 388 
Ptomaines, 213 

Publication of adulterated foods, 10 
Puffed wheat, 371 
Pulfrich refractometer, 86 
Pumpkin, composition of, 282 
Purine bases, 35 
Pycnometer, 45 
Pyroligneous acid, 788, 795 

in meats, 215 
Pyronin, 831 
Pyrosin, 826 

Quassiin, 759 
Quercetin, 832 
Quercitannic acid, 429 
Quercitron bark, 819, 823 
Quevenne lactometer, 118 
Quince essence, imitation, 954, 955 
Quinoline yellow, 831, 847, 855, 870 
Quotient of purity of sugar, 610 

Radishes, composition of, 282 
Raffinose, 37, 600 



1082 



INDEX. 



Raffinose, determination of, 650 
Rancidity, 489 
Rape oil, 539 

test for, 539 
seed, 539 
Raphides, 77 
Rapic acid, 29, 487 
Raspberries, composition of, 283 
Raspberry soda, 1012, 1013 
Reagents, 24 
Red colors, 815, 849 

ochre in sausages, 222 
pepper. See Cayenne and Paprika, 
wines, 714, 717, 718 
wood, 460 
Refractometer, 86 

Abbe, 86, 94 

Amagat and Jean, 86 

butyro, 86, 87 

heater for, 88 

immersion, 97 

in oil analysis, 493 

Pulfrich, 86 

sliding scale for, 93 

tables for, 90, 91, 92, 102, 

107, 493, 494, 533, S7o 
Wollny, 86, 126 
Reichert-Meissl method, 497 

number of butter and oleo 
fat, 570 
Reinsch test for arsenic, 761 
Renard peanut oil test, 543 

rosin oil test, 548 
Renovated butter, 563 

distinction from butter 
and oleomargarine, 571 
Resins, 76 
Resorcin brown, 856, 871 

yellow, 837, 847, 855, 870 
Respiration calorimeter, 2, 39 
Revis and Burnett starch method, 415 
Rhodamin B, 849, 857, 874 
3 B, 857, 874 
G, 857, 874 
S, 831, 857, 873 
Rhubarb, composition of, 282 
Ribose, 36 
Rice, ash of, 310 

coating, detection of, 287 
composition of, 280, 281 



Rice, microscopy of, 319 

polished, 282 

starch, 291 
Rice's expanded Meissl-Hiller table, 639 
Richardson water method, 423 
Riche and Bardy methyl alcohol method, 783 
Richmond cane sugar method, 171 

sliding milk scale, 140 
Rimini formaldehyde test, 881 
Ritsert acetanilide tests, 926 
Ritthausen milk proteins method, 132 
Robin acid color test, 844 

gelatin method, looi 
Roese-Gottlieb fat method, 193 
Roeser mustard oil method, 473 
Rohrig tube, 194 

Roi and Kohler peroxidase test, 173 
Rolled oats, 371 

wheat, 371 
Romijn formaldehyde method, 883 
Roos wine ratio, 723 
Root beer, 1013 
Ropy milk, 117 
Roquefort cheese, 197 
Rose, attar of, 953 

bengale, 815, 850, 856, 872 
3 B, 850, 856, 872 

extract, 953 

rose oil in, 953 
standards, 953 
Rosin oil, 548 
Rosindulin 2 G, 855, 871 
Rosolic acid, 856, 872 
Rota color scheme, 827 
Rubner's fuel value factors, 40 
Riihle-Brummer saponin method, 1015 
Rum, 774 

composition of, 774 

essence, 775 

methods of analysis, 777 

new, 775 

standards, 774 
Rye ash of, 310 

composition of, 280, 281 
microscopy of, 316 
proteins of, 309 
starch, 290 

Saccharimeter, 601 

double wedge, 604 



INDEX. 



1083 



Saccharimeter, forms of, 606 

normal weights for, 606 
scales compared, 606 
single wedge, 602 
Soleil-Ventzke, 601 
triple field, 604 
Saccharimetry, 600 
Saccharin, 905 

detection of, 906 
determination of, 907 
Saccharine products, 586 
Safflower, 819, S23 
Saffron, 815, 819, 822, 848 
Saffrosin, 856, 872 
Safranin, 815, 830, 852, 857, 873 
Sago, 291 
Saleratus, 348 
Salicylic acid, 887 

detection of, 888 
determination of, 890 
in butter, 561 
meat, 216 
milk, 167 
Salmin, 32 
Salted meats, 215 
Sample, preparation, 43 
Sanatogen, 204 
Sanger arsenic method, 64 

Black-Gutzeit method, 65 
Sanose, 204 

Saponification, 487, 503 
Saponin, 1014, 1015 

detection, 1015 
Sarcolemma, 215 
Sarsaparilla, 1013 
Sausages, color in, 222 

composition of, 220 
methods of analysis. See Meat, 
starch in, 221 
Sauterne wine, 714, 715, 717 
Savory extract standards, 950 

oil, standards, 950 
Sawdust, 466 
Scarlet G R, 855, 871 
Schardinger aldehyde reductase test, 174 
Schenk beer, 739 
Schiedam schnapps, 776 
Schiff aldehyde test, 882 
Schindler acidity method, 338 
Schlegel color method, 367 



Schmidt saccharin test, 907 
Schreiner colorimeter, 66 
Schultze reagent, 80 
Sclerenchyma, 74 
Scovell sampling tube, 118 
Sealed samples, 6, 145 
Seeker ginger method, 952 
Semolina, 363, 364 
Separatory funnel support, 58 
Seralbumin, 30 
Sericin, 31 
Serine, 35 
Sesame oil, 537 

adulteration of, 538 
composition of, 538 
constants, 528, 529, 538 
methods of analysis, 538. See 
also Oils. 
Baudouin test, 538 
Tocher test, 538 
Villavecchia and Fa- 
bris test, 538 
standards, 538 
seeds, 537 
Settimi soy oil test, 546 
Shannon formic acid method, 899 
Sherry wine, 714, 715, 717, 7i8 
Short cheese fat method, 205 
Shorts, wheat, 320 
Shredded wheat, 371 
Sieve tubes, 76 
Silent spirit, 763 
Sinabaldi asaprol method, 904 
Sinalbin, 47 

mustard oil, 470 
Sinapin thiocyanate, 469 
Sinigrin, 470 
Sinks, 15 
Sitosterol, 542 

Smith and Bartlctt tin method, 975 
Smoked meats, 215 
Snell electrical conductivity value, 661 

MacFarlane and Van Zoeren lead 
number, 659 
" Soaked " goods, 970 
Soap-bark, 1014 
Soda, cherry, 1013 

determination of, 313, 361 
lemon, 1012, 1013 
orange, 1012, 1013 



1084 



INDEX. 



Soda, raspberry, 1012, 1013 
strawberry, 1012, 1013 
vanilla, 1012, 1013 
water, ion 

syrups, 1012 
Sodium benzoate, 890 

bicarbonate, 348 

methods of analysis, 352 
bisulphate, 896 
carbonate, in milk, 166, 170 
hydroxide, tenth-normal solution, 24 
salicylate, 887 
Soja bean meal, 375 
Soleil-Ventzke saccharimeter, 601 
Solid yellow, 829 
Soluble blue, 854, 869 
Sorbose, 37 
Sorghum, 695 

Sostegni and Carpentieri dyeing test, 842 
Sour milk, 172 
Souring of milk, 116 
Soxhlet extractor, 52 

lactose method, 137, 139 
Soy oil, 528, 528, 545 
Spaghetti, 364. See also Pastes, edible. 
Sparkling wine, 714, 715, 717, 720 
Spearmint, extract, 949 

standards, 949 
oil, 949 
Specific gravity bottle, 45 

of beeswax, 675 
liquids, 43 
liquors, 686 
milk, 118 

serum, 151, 152 
temperature correc- 
tion for, 120 
oils, 490 
vinegar, 795 
rotatory power, 607 
Spent tea leaves, 388 
Spice extracts, 949 
Spices, 422 

adulterants of, 422, 427 
methods of analysis, 422 
alcohol extract, 424 
ash, 423 
crude fiber, 425 
ether extract, 424 
lime, 424 



Spices, methods of analysis, 

moisture, 423 
starch, 425 
sulphuric acid, 424 
volatile oil, 425 
microscopy of, 426 
Spiral ducts, 76 
Spirit vinegar, 788, 794 
Spirits, cologne, 763 
distilled, 763 
neutral, 763, 767, 768 
silent, 763 
standards, 763 
velvet, 763 
Spoon test for butter, 572 
Sprengel tube, 48 
Springers, 960 
Squash, composition of, 282 
Stachyose, 37 

Stahlschmidt caffeine method, 387 
Standard for allspice, 438 

almond extract, 943 

oil, 943 
anise extract, 949 

oil, 950 
beer, 742 
brandy, 772 
butter, 556 
cassia, 482 

extract, 950 
oil, 950 
cayenne, 460 
celery seed extract, 950 

oil, 950 
cheese, 198 
cinnamon, 442 

extract, 950 
oil, 950 
clove extract, 950 

oil, 950 
cloves, 432 • 
cocoa, 417 
cream, 186 
foods, 4 

fruit butter, 986 
ginger, 466 

extract, 950 
ice cream, 191 
ketchups, 977 
lard, 579 



I 



INDEX. 



1085 



Standard for lemon extract, 927 
oil, 928 
mace, 484 

maple products, 594 
meat extracts, 252 
meats, 213 
milk, 145 
mince meat, 987 
molasses, 651 
mustard, 476 
nutmeg, 482 

extract, 950 
oil, 950 

olive oil, 531, 532 
orange extract, 941 

oil, 941 
pepper, 449 
peppermint extract, 949 

oil, 949 
renovated butter, 563 
rose extract, 953 

oil, 953 
rum, 774 
savory extract, 950 

oil, 950 
sesame oil, 538 
spearmint extract, 949 

oil, 949 
staranise extract, 950 

oil, 950 
starch sugar, 596 
sugars, 587, 596, 594 
sweet basil extract, 950 
oil, 950 
marjoram extract, 950 
oil, 951 
thyme extract, 951 

oil, 951 
tonka extract, 917 
vanilla extract, 917 
vinegar, 803 
wintergreen extract, 947 

oil, 947 
wine, 716 
whiskey, 766 
Standard solutions, equivalents of, 25, 26 

refractometric readings 
of, 106 
Staranise extract, standards, 950 
oil, standards, 950 



Starch, 38, 76, 288 

arrowroot, 291 
barley, 290 
bean, 291 
buckwheat, 290 
classification of, 289 
corn, 290 

detection of, 288, 991 
determination of, 292, 305 
by acid conversion, 392 
diastase method, 292 
in baking powder, 360 
cereals, 292, 305 
jams and jellies, 991 
milk, 171 
sausages, 240 
spices, 425 
oat, 291 
pea, 291 
potato, 291 
rice, 291 
rye, 290 
sago, 291 
syrup, 598 
tapioca, 291 

under polarized light, 292 
wheat, 289 
Stearic acid, 29, 487 
Stearin, beef, 582 

cottonseed, 536 
lard, 579 
Sterilized butter, 563 
Still, alcohol, 688, 689 
fractionating, 56 
nitrogen, 60, 62 
water, 20 
wine, 714 
Stilton cheese, 197 

Stone carbohydrate separation method, 304 
Stout, 740, 743- See also Beer. 
Strawberry soda, 1012, 1013 
Strawberries, composition of, 283 
Strippings, 113 
Stutzer gelatin method, 228 
Suberin, 76 

Sucrate of lime, 187, 189 
Sucrose. See Cane sugar. 
Suction pump, 18 
Sudan, I, 815, 829, 849, 858, 875 
II, 852, 858, 875 



1086 



INDEX. 



Sudan, III, 852, 858, 875 
IV, 858, 87s 
G, 849 
Suet, 550 

Sugar, 586. See also Cane sugar, 
beet, 590 
brown, 589 
cane, 588 

classification of, 586 
composition of,' 589 
determination by copper reduction, 

614 
grape. See Dextrose, 
in fruits, 587 

jams, 987 
maple. See Maple syrup, 
muscovado, 589 
raw, 589 
refining, 591 
standards, 587, 594, 596 
ultramarine in, 591, 613 
Sulphur, determination of, 313 
Sulphuric acid determination, 313, 362 

in baking chemicals, 362 
vinegar, 748 
Sulphuring, 591, 896 

of fruits, 1003 
Sulphurous acid, 896 

detection of, 897 
determination of, 897 
in butter, 562 
meat, 216, 238 
Sumac, 819, 823 
Sun yellow, 854, 868 
Sunflower oil, 547 

seeds, 547 
Sweet basil extract, standards, 950 
oil, standards, 950 
marjoram extract, standards, 950 

oil, standards, 951 
wine, 714, 715, 717, 718, 719 
Sweeteners, artificial, 905 
Swells, 960 
Swiss cheese, 197 
Sy lead method, 660 
Syrup, analysis of, 642 
ashing of, 609 
corn. See Glucose, 
golden, 591 
drip, 591 



Syrup, maple. See Maple syrup. 

mixing. See Glucose. 

sorghum, 596 

starch. See Glucose. 
Syrups, fruit, loio 

soda water, 1012 

Tallow, 550 
Tannin in cloves, 429 
tea, 379 
wine, 716 
Tapioca, 291 
Tartaric acid, 38 

in baking powder, 349, 356 
fruit products, 1008 
Tartrate baking powders, 349 
Tartrazin, 826, 833, 834, 837, 847, 854, 861 
Tatte, 174 
Tea, 378 

acidity, 1035 
adulteration of, 387 
ash, 381, 382 
astringents in, 390 
caffeine in, 379, 380, 381, 385 
composition of, 379, 380, 381 
exhausted leaves in, 388 
facing of, 387 
foreign leaves in, 388 
leaf, characteristics of, 389 
methods of analysis, 381 
acidity, 1035 
ash, 382 

alkalinity of, 382 
astringents, 390 
caffeine, 386 
crude fiber, 381 
essential oils, 382 
ether extract, 381 
extract, 383 
facing, 387 
insoluble leaf, 382 
protein, 382 
tannin, 383 
theine, 385 
water, 381 
microscopy of, 391 
spent leaves in, 388 
stems in, 389 
tablets, 390 
tannin in, 379, 383 



INDEX. 



1087 



Tea, theine in, 386 

Teller protein separation method, 307 

Tetracyanol S F. See Patent blue. 

Tetrasaccharides, 37 

Tetroses, 36 

Theobromine, 35, 410 

determination of, 413 
Thioflavin T, 857, 873 
Thompson boric acid method, 886 
Thyme extract, standards, 951 

oil, standards,! 951 
Tin, action of fruits and vegetables on, 961 
963, 964 
coating, influence of different weights, 

964 
determination of, 972, 973, 974 
salts in molasses, 651, 655 
Tintometer, Lovibond, 67 
Titer test, 518 
Tocher sesame oil test, 538 
Tomato ketchup. See Ketchup. 
Tomatoes, composition of, 282 
Tonka bean, 917 

tincture, 917 
Trehalose, 37 

Trillat methyl alcohol test, 782 
Trioses, 36 
Trisaccharides, 37 
Tropaeolin O. See Resorsin yellow. 
Tryptophane, 35 
Turmeric, 467, 815, 819, 821, 823, 849 

as an adulterant, 469 

composition, 468 

curcmuin in, 467 

in butter, 557 

methods of analysis. See Spices. 

microscopy of, 468 

tests for, 821 
Turnips, composition of, 282 
Tyrosine, 35 

Ulrich cocoa-red method, 417 
Ultramarine blue, 816 

. in sugar, 591, 613 
tea, 387 
Uno beer, 746 
Unsaponifiable matter, 520 
Uranin, 856, 872 

Vacuoles in yeast cells, 347 



Valine, 35 

Van Slyke protein formul?., 140 

separation method in 
cheese, 200 
in milk, 133 
Vanilla bean, 911, 912 

exhausted, 913 
extract, 911 

acetanilide in, 918, 925, 

926 
adulteration of, 917 
alkali in, 914 
artificial, gi8 
color value of, 915, 926 
composition of, 912, 914, 

915,916 
coumarin in, 917, 920, 923, 

924 
glycerol in, 913, 926 
lead number of, 915, 925 
methods of analysis, 919 
acetanilide, 925, 926 
acidity, 927 
alcohol, 926 
ash, 927 
caramel, 926 
coumarin, 920, 923, 924 
glycerol, 926 
lead number, 925 
resins, 919 
sugars, 926 
vanillin, 920, 922, 924 
preparation of, 913 
prune juice in, 918 
resins in, 919 
standards, 917 
tannin in, 920 
tonka in, 917 

vanillin in, 913, 915, 920, 
922, 924 
soda, 1012, 1013 
Vanillin, 913 

determination, 920, 922, 924 
microscopical structure, 924 
Vaporimeter, 704 
Veal, bob, 217 

composition of, 209 
cuts of, 209 
Vegetable colors. See Colors, vegetable, 
in sausages, 241 



1 



1088 



INDEX. 



Vegetables, 282 

ash of, 311 
canned, 957 
composition of, 282 
methods of proximate analysis 
of, 285 
Ventilation, 15 

Vermicelli, 364. See also Pastes, edible. 
Vessels, 76 

Victor Chemical Works lead method, 362 
Victoria yellow, 815, 829, 847, 856, 872 
Villavecchia and Fabris sesame oil test, 538 
Vinegar, 788 

acidity of, 790, 796, 797, 798 

acids of, 796, 797 

adulterated, 809 

adulteration of, 803, 804 

alcohol in, 792, 797 

apple, 803 

ash of, 790, 791, 792, 793, 794, 795, 

806 
beer, 792 
caramel in, 810 
cider, 790, 803 

artificial, 805 
cask, 789, 790 
generator, 789, 791 
glycerol in, 791, 801 
composition of, 790, 791, 792, 793, 

794, 806, 809 
distilled, 794, 804 
generators, 789 
glucose, 794, 804 
glycerol in, 791, 801 
grain, 804 

Hortvet number of, 799 
hydrochloric acid in, 798 
imitation, 774 
malt, 792, 804 
manufacture of, 789 
methods of analysis, 795 
acids, fixed, 797 

mineral, 797, 798 
total, 796 
volatile, 797 
alcohol, 797 
arsenic, 811 
ash, 795 
caramel, 810 
copper, 8n 



Vinegar, methods of analysis 

furfural, 810 

glycerol, 801 

hydrochloric acid, 798 

lead, 810 

acetate test, 809 
number, 799 

malic acid, 798 

metals, 810 

nitrogen, 796 

pentosans, 801 

phosphoric acid, 795 

potassium acid tartrate, 8cxj 

reducing matters, 801 

solids, 795 

specific gravity, 795 

sugar, 800 

sulphuric acid, 798 

zinc, 810 
molasses, 794, 806 
phosphoric acid in, 790, 792, 793, 

795 
polarization of, 790, 800, 806, 807, 

808, 809 
reducing matter in, 790, 801, 806 
residue of, 805 
specific gravity of, 792, 793, 794 

795 

spices in, 810 

spirit, 794, 804, 806 

standards, 803 

sugar, 804 

sugars in, 790, 792, 800, 807 

tartrate in, 800 

varieties of, 788 

wine, 792, 804 

wood, 795, 810 
Vinous fermentation, 682 
Violamin R, 831, 855, 871 
Viscogen, 187 
Viscosity of cream, 187 

oils, 492 
Vitafer, 204 
Vitellin, 32, 271 
Vitellose, 5^ 

Waage Bombay mace test, 485 
Walnut ketchup, 977 
Walnuts, composition of, 284 
Water-bath, 19 



INDEX. 



1089 



Water glass, 273 

Waterhouse butter test, 573 

Watermelons, composition of. 283 

Weiss beer, 740 

Weld, 819, 823, 848 

Wendt hydrogen electrode apparatus, 1025 

Werner-Schmidt fat method for cheese, 200 

milk, 126 
West benzoic acid method, 895 
Westphal balance, 44 
Wheat, 280, 281 

ash of, 310 

composi'Lion of, 280, 281, 320 
microscopy of, 315 
proteins of, 305-309 
shredded, 371 
starch, 289 
Whiskey, 764. See also Distilled liquors 
adulteration of, 770 
aging of, 764 
American, 767 
blended, 766 
Bourbon, 766, 768, 769 
British, 767 
composition of, 767 
corn, 766 
imitation, 771 
Irish, 767 

manufacture of, 764 
methods of analysis, 777 
rye, 766, 768, 769 
Scotch, 766 
standards, 765, 766 
Wichmann coumarin test, 923 
Wijs iodine absorption method, 509 
Wild saccharimeter, 606 
Wiley bromine pipette, 512 

and Ewell double dilution sugar 
method, 136, 650 
Wilkinson and Peters test for peroxidase, 1 73 
Wine, 713 

acetal in, 716 
acetaldehyde in, 716 
adulteration of, 720 
alum in, 725 
ameliorated, 720 
arsenic in, 716 
boric acid in, 716 
Burgundy, 714, 715, 717 
butyric acid in, 716 



Wine, California, 718 

cane sugar in, 721 

Cazeneuve color method, 736, 737 

chaptalizing, 721 

chianti, 714, 715, 717 

citric acid in, 716 

claret, 714, 715, 717 

classification of, 714 

colors in, 725, 736, 737 

composition of, 717, 718 

constituents, 715 

copper in, 716 

corrected, 720 

dealcoholized, 714 

"dry," 714, 715, 717 

Dupre color method, 736 

ethers in, 716 

fortified, 714, 719, 723 

fruit other than grape, 725 

furfural in, 716 

gallizing, 722 

Gau tier's rule, 722 

glycerol, 716, 734 

Halphen ratio, 723 * 

hexamethylene tetraamine in, 725 

hock, 715 

inosite in, 716 

lactic acid in, 716 

Madeira, 714, 715, 717 

malic acid in, 716 

manganese in, 716 

mannite in, 716 

manufacture of, 713 

methods of analysis, 726 

acids, total, 726 
volatile, 726 

alcohol, 726 

ash, 726 

colors, 736 

cream of tartar, 732 

extract, 726 

glycerol, 734 

lactic acid, 732 

nitrates, 735 

potassium sulphate, 735 

preservatives, 736 

reducing sugars, 734 

sodium chloride, 735 

specific gravity, 726 

tannin, 735 



1090 



INDEX. 



Wine, methods of analysis 

tartaric acid, free, 731, 732 
total, 731 

methyl pentoses in, 716 

modified, 720 

Moselle, 714, 715, 717 

natural, 714 

nitrates in, 723, 735 

cenocyanin in, 713, 716 

oxalic acid in, 716 

pentoses in, 716 

phosphoric acid in, 716 

piquette, 724 

plastering, 721 

polarization of, 734 

pomace, 724 

port, 714, 715, 717 

potassium sulphate in, 716, 735 

preservatives in, 725, 736 

proprionic acid in, 716 

quercetin in, 716 

red, 714, 715, 719 

reducing sugar in, 716, 734 

resin, 720, 725 

Rhine, 714, 715, 717 

Roos ratio, 723 

salicylic acid in, 716 

sauterne, 714, 715, 717 

scheelizing, 725 

sherry, 714, 715, 717 

sodium chloride in, 725, 735 

sparkling, 714, 715, 720 

standards, 716 

still, 714 

succinic acid in, 716 

sweet, 714, 715, 717 

tannin in, 716, 735 

tartaric acid in, 716, 731, 732 

Tokay, 715, 717 

varieties of, 714 

vinegar, 788, 792 

watering of, 722 

white, 714, 715, 719 

yeast of, 713 
Wintergreen extract, 947 

adulteration of, 947 
wintergreen oil in, 947 
oil of, 947 
Winton lead number, 658, 799, 925 
moisture apparatus, 50 



Winton, Ogden, and Mitchell alcohol extract 

method, 424 
insoluble leaf 
method, 382 
piperine meth- 
od, 447 
Wolfbauer titer test method, 518 
Wollny milk fat refractometer, 86, 126 
tables for using, 128 
table for converting Woll- 
ny degrees into wjj, 138 
Wood vinegar, 795, 810 
Woodman and Burwell formic acid test, 899 
Davis benzaldehyde method, 

988 
Taylor caffetannic acid meth- 
od, 396 
Wool, double dyeing method with, 818, 821, 
842 
dyeing of, 841 
for color tests, 841 
green S, 854, 868 
vegetable colors on, 818, 821 
Wormy fruit, 1004 

Xanthine, 35, 205 
Xantho-proteic reaction, 34 
Xylan, 38 
Xylose, 36 

Yeast, 343 

adulteration of, 346 
composition of, 345 
compressed, 344 
dry, 344 
extracts, 252 
in cider, 707 
wine, 713 
leavening power, determination of- 

347 

microscopy of, 346 

standard, 346 

starch in, 346 
Yellow colors, 815, 847 

fat color, 858, 875 
Yogurt, 174 

Zega oleomargarine test, 576 

Zein, 31, 309 

Zinc salts, 966, 1004 

determination of, 973 



PLATE I. 



CEREALS. 





Fig. 121. — Barley, Xiio. 

Transverse section, showing in order, pericarp, 

seed coats, aleurone layer, and starch cells. 



Fig. 122. — Barley, X55. 
Surface view of epidermis with hairs. 




Fig. 123. — Barley, X125. 
Surface view of upper chaff layer. 



Fig. 124. — Barley Starch, X220. 



CEREALS. 



PLATE U. 




Fig. 125. — Buckwheat, Xno. 

Transverse section through part of pericarp, seed 

coat, and part of endosperm. 



Fig. 126. — Buckwheat, Xiio. 
Surface view of scutellum. 




Fig. 127. — Buckwheat, Xiio. 
Surface section. Aleurone or proteid layer. 












--^ o 






St ^^'6^ 









Fig. 128. — Buckwheat Starch, X220. 
Starch granules separated. 



PLATE III. 



CEREALS. 




**^ 




Fig. 129. — Buckwheat Starch, Xno. 
Starch grains in masses. 



Fig. 130. — Corn, Xno. 
Transverse section through pericarp, seed coat, 
proteid layer, and part of endosperm, showing 
starch cells. 






Fig. 131. — Corn, Xno. 
Surface view showing two layers of the mesocarp. 



Fig. 132. — Com, Xno. 
Surface section. Proteid layer. 



CEREALS. 



PLATE IV. 






■■^'^•'■<^^ 








Pi^. 



Fig. i33._Com Starch, X220. 




Fig. 134. — Cornstarch, X22C. 
With polarized light. 




Fio. 135.— Oat, Xiio. 
Transverse section through chaff. 



Fig. 136.— Oat, Xiio. 
Surface section. Proteid layer with fragments of 
epidermis and hairs. 



PLATE V. 




Fig. 137.— Oat, Xiio. 
Surface view of upper chaff layer. 



Fig. 138.— Oat, X55. 
Surface view of epidermis and hairs. 




Fig. i39._Oat Starch, X220, 




Fia. 14c — Ri^e, X no 

Transverse section through seed coat and part of 

endospenn. 



CEREALS. 



PLATE VL 




Fig. 141. — Rice, Xiio. 
Surface section through starch cells. 



Fig. 142. — Rice, Xno. 
Surface view of upper chaff layer. 



-Ai 



\^ 



V 



^ -Kf)^- 



J ^ 












Fig. 143. — Rice Starch, X220. 




Fig. 144. — Rye, X 18 
Transverse section through the entire prain 



PLATE VII. 



CEREALS. 




Fig. 145. — Rye, Xiio. Fig. 146. — Rye, Xiio. 

Transverse section through pericarp, seed coat. Surface view of epidermis and underlying layers, 
aleurone layer, and starch cells of endosperm. 




Fig. 147. — Rye, Xiio. 
Surface view of epidermis and of seed eoat. 



_^». ;«He^e'niip<^^ 



P#1' 








Fig. 148. — Rye Starch, X220. 



PLATE VIII. 




CEREALS. 




Fig. 149.— Wheat, Xiio. Fig. 150.— Wheat, X no. 

Transverse section through pericarp, seed coat, Surface view of outer and inner epidermis Also 
proteid layer, and starch cells of endosperm. showing proteid layer. 








Fig. 151. — Wheat, Xiio. 
Surface view of epidermis, with hairs. 






Fig. 152. — Wheat Starch, X220. 



LEGUMES. 



PLATE IX. 








Fig. 153. — Bean, X no- 
Transverse section through starch cells. 



Fig. 154. — Bean Starch, X220. 




Fig. 155. — Bean, Xno. 
Transverse section through hull, showing palisade 
cells of epidermis, and underlying hypoderma. 



Fig. 156. — Lentil, Xno. 
Transverse section through hull and part of endo- 
sperm, showing some of the starch cells. 



PLATE X. 



LEGUMES. 




Fig. 157 — Lentil, Xiio. 
Surface view of epidermis. 



Fig. 158.— Pea, Xiio. 
Transverse section through hull and seed coat, 
showing outer palisade cells and underlying 
hypoderma. 




/ 



Fig. 159. — Pea, Xiio. 
Surface section through base of palisade layer. 



Fig. 160. — Pea, Xiio. 
Powdered pea hulls. 



PLATE XI. 



LEGUMES. 




Fig. i6i. — Pea, Xiio. 
Surface view of palisade cells. 



Fig. 162. — ^Pea, Xiio. 

Transverse section through starch cells. 





r5^^* 




Fig. 163. — Pea, X30. 
Transverse section through starch cells. 



Fig. 164. — Pea Starch, X220. 



MISCELLANEOUS STARCHES. 



PLATE XII. 




Fig. 165. — Potato Starch, X220. 



Fig. 166. — Potato Starch, X220. 
With polarized light. 



^X^' 




Fig. 167. — Arrowroot Starch, X220, 




Fig. 168. — Tapioca Starch, X220. 
(Cassava.) 



TURMERIC. SAGO. 



PLATE XIII. 





Fig. 169. — Turmeric, X 7°- 
Transverse section through rhizome. 



Fig. 170. — Turmeric, Xiio. 

Longitudinal section. Note spiral ducts through 

the center. 




Fig. 171. — Powdered Turmeric, Xno. 

Showing starch grains, fragments of cell tissue, 

coloring "natter, etc. 



Fig. 172. — Sago Starch, X220. 



PLATE XIV. 



COFFEE. 




Fig. 173.— Raw Coffee, Xiio. Fig. 174. — Roasted Coffee, X130, 

Transverse section of outer portion of endosperm. Transverse section through parenchyma of endo- 
sperm. 




Ftg. 17=5. — Coffee, Xno. 
Surface view of seed coat. 



L 








Fig. 176. — Coffee, Xnc. 

Roasted, ground coffee, showing fragments of 

endosperm parenchyma and of seed coat. 



PLATE XV. 



COFFEE. CHICORY. 




>f ■ 



Fig. 177. — Adulterated Coffee, X130. 
Dark masses of roasted pea starch are shown, 
with transparent fragments of the palisade 
cells of the pea-hull. 



Fig. 178. — Adulterated Coffee, X 130. 
The vascular ducts of chicory show most con- 
spicuously in this field. 




Fig. 179. — Chicory, X25. 
Transverse section through the root. 



Fig. 180. — Chicory, Xiio. 
Transverse section. 



PLATE XVI. 



CHICORY. COCOA. 




Fig. i8i. — Chicons Xno. Fig. 182. — Chicory, Xiio 

Tangential section, showing reticulated ducts and Radial section, showing bark parenchyma and 
wood parenchyma. milk ducts. 




j^' - 








a. ' 




fs 


■ w ^ 



fifa. J^ 




Fig. 183.— Chicory, Xiio. FiG. 184.— Cocoa, Xiio. 

Roasted and ground, showing fragments of Transverse section through periphery of seed 
ducts and other tissues. seed coats, and cotyledon. * 



COCOA. 



PLATE XVII. 



t 



^^^ 




R^~-:^^ 






>.^' ■- ■-■.-1 



Fig. 185. — Powdered Cocoa, Xno. 




Fig. 186. — Adulterated Cocoa, Xiio 

Showing admixture of arrowroot with the cocoa 

powder. 




Fig 187. — Cocoa Shell, Xiio. 
Transverse section through epidermis, pulp, and 
mucilaginous layers of the pericarp and seed 
eoat. 



Fig. 188, — Cocoa Shell, X nc. 
Longitudinal section through shell 



PLATE XVIII. 



TEA. SPICES. 




Fig. 1S9. — Tea, X55- 
Transverse section through midrib of leaf. Note 
the paUsade layer below the upper epidermis, 
the inner wood vessels above the center, and 
the parenchyma of the pulp. 



Fig. 190. — Tea, >C no. 
Surface view of lower epidermis, \vith stomata and 
one of the hairs. 




Fig. 191. — Allspice, X9. 
Transverse section through the entire berry, show- 
ing the two cells, with kidney shaped seed in 
each. 



Fig. 192. — Allspice. X70- 

Transverse section through pericarp, showing oil 

spaces and stone cells. 



PLATE XIX. 



SPICES. 





Fig. 193. — Allspice Seed, Xno. 

Transverse section through seed shell and part of 

embryo, showing starch cells. 



Fig. 194. — Allspice Seed, Xno. 
Transverse section through the resinous portion of 
the seed coat, showing port wine colored lumps 
of gum or resin. 







tx 




Fig. 195. — Powdered Allspice, Xno. Fig. 196.— Adulterated Allspice, Xno. 

Showing stone cells, resinous lumps, and starch. Showing a large fragment of the seed skin of 

cayenne at the left. 



SPICES. 



PLATE XX. 




Fig. 197. — Cassia Bark, X45- 
Transverse section through the bark. 



Fig. 198. — Cassia Bark, X45. 
Longitudinal section. 




Fig. 199. — Cassia Bark, Xiio. 
Transverse section, showing cork cells, parenchy- 
ma, and stone cells. 



Fig. 200. — Cassia Bark, Xiio. 
Longitudinal section, showing bunches of bast 
fibers at the left, starch cells in the center, and 
stone cells at the right. 



SPICES. 



PLATE XXL 





I 



Fig. 20I. — Ccvi.in ( innamon Bark, Xiio. Fig. 202. — Ceylon CiiiMaiiiDn Hark, Xiio. 

Transverse section, slinwins; many bast fibers and Longitudinal section, showinc; bast fibers, stone 
starch cells. cells, and parenchyma. ^ 




Fig. 203. — Powdered Cassia, Xno. 
Showing stone cells, starch, and corky tissue. 



Fig. 2C4. — Powdered Cassia, Xiio. 
Showing bast fibers and starch. 



SPICES. 



PLATE XXII. 




Fig. 205. — Powdered Cassia, X no. 
Showing large bast fiber and starch grains. 



Fig. 206. — Adulterated Cassia, Xiio. 
A mass of foreign bark. 




Fig. 207. — Cayenne, Xiio. 
Transverse section through pericarp. 



Fig. 208. — Cayenne, Xiio. 
Transverse section through seed coat and part of 
endosperm. Collapsed parenchyma cells sepa- 
rate endosperm from long epidermal cells. 



SPICES. 



PLATE XXIII. 




Fig. 209. — Cayenne, Xiio. 
Surface view of fruit epidermis. 



Fig. 210. — Cayenne, Xiio. 
Surface view of two layers of seed coat. 





Fig. 211 . — Powdered Cayenne, X 1 10. 
A large mass of fruit epidermis. 



Fig. 212. — Powdered Cayenne, Xiio. 
Showing chiefly two of the seed coat layers. 



PLATE XXJV. 



SPICES. 




Fig. 213. — Adulterated Cayenne, X130. Fig. 214. — Adulterated Cayenne, X214. 

Com and wheat starch and cocoanut shells appear The central mass is ground red wood, surrounded 
chiefly. A bit of cayenne is shown at the right. by corn starch grains. 




Fig. 215.— Clove, X65. Fig. 216.— Clove, Xiio. 

Transverse section from the center outward to Transverse section near epidermis, showing large 
epidermis, showing parenchyma. oil cavities. 



1 



SPICES. 



PLATE XXV. 




>^-( 




Fig. 217. — Clove, X38. 
Longitudinal section through entire clove. 



Fig. 218. — Clove, X70. 
Central longitudinal section, showing duct bundles. 




Fig. 219. — Clove, Xiio. 
Surface view of epidermis. 



Fig. 220. — Powdered Cloves, X130. 
Dense, spongy tissue, with small oil drops. 



PLATE XXVI. 



SPICES. 





Fig. 221. — Clove Stem, X70. Fig. 222. — Clove Stem, X25. 

Transverse section through outer part of stem, Central longitudinal section through entire stem, 

showing bast fibers at the left, parenchyma in showing bast fibers in the center, and stone cells 

the center, and stone cells near the epidermis. at the right. 




Fig. 223. — Clove Stem, X 70. 
Longitudinal section, showing the stone cells. 



Fig. 224. — Powdered Clove Stems, Xiio. 

Showing fragments of tissues, stone cells, and bast 

fibers. 



SPICES. 



PLATE XXVII. 




Fig. 225. — ^Powdered Clove Stems, Xiio. 
Showing bundle of bast fibers. 



Fig. 226. — Adulterated Cloves, X130. 
Showing chiefly stone cells of cocoanut shells. 




A . ''■■"'■ -W-' 













v>E^ 



Fig. 227. — Adulterated Cloves, X130. Fig. 228. — Ginger, Xiio. 

With large admixture of cocoanut shells. Transverse section, showing starch cells with 

contents. 



PLATE XXViiI. 



SPICES. 




Fig. 229.— Ginger, Xno. Fk,. 230.— Ginger, ,> no. 

Transverse section, showing parenchyma, starch Longitudinal section, showing spiral ducts and 
grains, and duct vessels. pigment cells. 




Fig. 231. — Ginger Starch, X220. 



Fig. 232. — Adulterated Ginger, X 130. 
A mass of wheat bran tissue is most conspicuous. 



PLATE XXIX. 



SPICES. 




Fig. 233. — Adulterated Ginger, X 130. 






k 
d."'" 



'»► 






-i^^l 



qO 






-i^ ,A^^ 









Fig. 234. — Adulterated Ginger, X130. 




The central dark mass is a yellow fragment of Containing a large admixture of corn and wheat 
turmeric. starches. 







Fig. 235. — IVnantz: Mace, Xiio. FiG. 236. — Bombay or Wild Mace, Xiio. 

Transverse section through epidermis and oil cells, Transverse section through outer layers, showing 
showing also parenchyma with contents of yellow and red resinous lumps, 

amylodextrin. 



PLATE XXX. 



SPICES. 





f^f t: 



Fig. 237. — Nutmeg, Xiio. 
Transverse section through the exterior and in- 
terior teguments of the seed and part of the 
endosperm, showing starch cells. 



A^ 



Fig. 238. — Nutmeg, X25. 
Transverse section near exterior of seed. 




Fig 239. — Nutmeg, X no. 

Surface view of seed coat, showing also portions of 

underlying tissues. 



Fig. 240. — Powdered Nutmeg, Xiio. 



PLATE XXXI. 



SPICES. 




Fig. 241. — Wliite ^Tustard, Xiio 
Transverse section through mucilaginous epider- 
mis, sub-epidermal parenchyma layer (square 
cells), palisade cells, and broken parenchyma 
layer of the hull. 



Fig. 242. — White Mustard, Xno. 

Transverse section through the tissue of the 

radicle. 




Fig. 24^5. — White Mustard Xito 
Surface view of two layers of the hull or seed coat. 



Fig. 244. — \¥hite Mustard. Xno. 
Surface section through palisade cells and under- 
lying layer of the seed coat. 



PLATE XXXII. 



SPICES. 




Fig. 245.^l3lack Mustard, Xiio. FiG. 246. — Black Mustard, Xno. 

Transverse section, showing fragments of the epi- Surface view of two of the seed coat layers, 
dermis and dark colored palisade cells of the 
seed coat. 




Fig. 247. — Ground Mustard, X130. 
Ground without removal of the oil. 



Fig. 248. — Ground Mustard Hulls, Xiio. 



PLATE XXXIII. 



SPICES. 





^•^\ 



\. 



Fig. 249. — Dakota Mustard Flour, Xiio. FiG. 250. — Adulterated Mustard Flour, X130. 

Dark spots show starch grains of foreign weed Showing masses of wheat starch, 

seed, stained with iodine. 



Xi^ 





Fig. 251. — Pepper, Xno. 
Transverse section through inner part of pericarp 
(including parenchyma and seed coat layers) and 
portion of perisperm, showing starch and oil 
cells. 



Fig. 252. — Pepper, Xno. 
Surface view of hypodermal layer. 



SPICES. 



PLATE XXXIV. 




Fig. 253. — Pepper, Xno. 
Transverse section through outer part of pericarp, 
showing epidermis, underlying stone cell layers, 
parenchyma, and seed coat. 



Fig. 254. — Pepper, Xiio. 
Surface section through stone cell layer 



#: 



'■'% 









■\ 


' , •* * 






• 


• >»-/^'{";<-.^ 


r'"- 


9 / ? f \5 " * 





^ / * . '^ . * 

Fig. 255. — Pepper Starch, X220. 
Starch granules separated. 





Fig. 256. — Pepper Starch, Xiio. 
Starch grains in masses. 



SPICES. 



PLATE XXXV. 




Fig. 257. — Ground Pepper Shells, Xno. 
Mainly sho\\ang stone cells. 





*•«*. 



-^ 



Fig. 258. — Adulterated Pepper, X130. 
Showing wheat and buckwheat starches. 




t 



^'fU' 






'^' 



^^ 



' /** 



i^- 



*^ 



'. ^ ♦/ '1' 







Fig. 259. — Adulterated Pepper, X 130. 
Showing wheat, corn, and rice starches. 



Fig. 260. — Adulterated Pepper, X 130. 
The large, lower mass shows buckwheat starch, 
while the finer-grained mass near the top is of 
pepper. 



PLATE XXXVI. 



SPICES. SPICE ADULTERANTS. 







Fig. 261. — Adulterated Pepper, Xiio. Fig. 262. — Adulterated Pepper, X130. 

The central mass shows the sclerenchyma cells of Cayenne and wheat starch are the adulterants. 

olive stones. 












&■• >' --^klrra ., - -i.^ .- tf •<■■':■*, ■vie- - <^ ■ ^."^.^ \i 



ffm-ymf>:: 



"^'.4 












Fig. 263. — Powdered Olive Stones, Xiio. 




Fig. 264. — Powdered Cocoanut Shells, X 1 10 



PLATE XXXVII. 



SPICE ADULTERANTS. 








Fig. 265. — Powdered Elm Bark, Xno. 



Fig. 266. — Pine Sawdust, Xiio. 
Finely ground. 







m * m m 






- ^■'*^^J«^'^«••*;|- 



Fig. 267. — Pine Wood, Xno. 
Transverse section. 




^4 



Fig. 268. — ^Pine Wood, Xno. 
Radial and tangential sections. 



PLATE XXXVIll. 



EDIBLE FATS. 




Fig. 269. — Pure Butter, X25. 
With polarized light and selenite plate. 




Fig. 270. — Process or Renovated Butter, X25. 
With polarized light and selenite plate. 



Fig. 271. — Oleomargarine, X25. 
With polarized light and selenite plate. 



PLATE XXXIX. 



EDIBLE FATS. 




Fig. 272. — Lard Stearin, Xiio. 
Leaf lard, crystallized from ether. 



Fig. 273. — Lard Stearin, X220. 
Leaf lard, crystallized from ether. 




Fig. 274.- Lard :Dlearin, X220. 
" Back" lard, crystallized from ether. 



Fig. 275.— Lard Stearin, X480. 
"Back" lard, crystallized from ether. 



PLATE XL. 



EDIBLE FATS. 




Fig. 276. — Beef Stearin, >Cs5- 
Crystallized from ether. 




Fig. 277. — Beef Stearin, Xiio. 
Crystallized from ether. 




Fig. 278. — Beef Stearin, X220. 
Crystallized from ether. 



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X 

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